计算机网络英文试题

合集下载

计算机网络英文题库(附答案)chapter5

计算机网络英文题库(附答案)chapter5

Chapter 5 The Link Layer and Local Area Network1.A ( ) protocol is used to move a datagram over an individual link.A application-layerB transport-layerC network-layerD link-layer2.The units of data exchanged by a link-layer protocol are called ( ).A datagramsB framesC segmentsD messages3.Which of the following protocols is not a link-layer protocol? ( )A EthernetB PPPC HDLCD IP4.In the following four descriptions, which one is not correct? ( )A link-layer protocol has the node-to-node job of moving network-layer datagrams over a single link in the path.B The services provided by the link-layer protocols may be different.C A datagram must be handled by the same link-layer protocols on the different links in the path.D The actions taken by a link-layer protocol when sending and receiving frames include error detection, flow control and random access.5.Which of the following services can not offered by a link-layer protocol? ( )A congestion controlB Link AccessC Error controlD Framing6.( ) protocol serves to coordinate the frame transmissions of the many nodes when multiple nodes share a single broadcast link.A ARPB MACC ICMPD DNS7.In the following four descriptions about the adapter, which one is not correct? ( )A The adapter is also called as NIC.B The adapter is a semi-autonomous unit.C The main components of an adapter are bus interface and the link interface.D The adapter can provide all the link-layer services.8.Consider CRC error checking approach, the four bit generator G is 1011, and suppose that the data D is 10101010, then the value of R is( ).A 010B 100C 011D 1109.In the following four descriptions about random access protocol, which one is not correct? ( )A I n slotted ALOHA, nodes can transmit at random time.B I n pure ALOHA, if a frame experiences a collision, the node will immediately retransmit it with probability p.C T he maximum efficiency of a slotted ALOHA is higher than a pure ALOHA.D I n CSMA/CD, one node listens to the channel before transmitting.10.In the following descriptions about MAC address, which one is not correct? ( )A T he MAC address is the address of one node’s adapter.B N o two adapters have the same MAC address.C T he MAC address doesn’t change no matter where the adapter goes.D M AC address has a hierarchical structure.11.The ARP protocol can translate ( ) into ( ). ( )A h ost name, IP addressB h ost name, MAC addressC I P address, MAC addressD broadcast address, IP address12.The value of Preamble field in Ethernet frame structure is ( )A 10101010 10101010……10101010 11111111B 10101011 10101011……10101011 10101011C 10101010 10101010……10101010 10101011D 10101010 10101010……10101010 1010101013.There are four steps in DHCP, the DHCP server can complete ( ).A DHCP server discoveryB DHCP server offersC DHCP requestD DHCP response14.In CSMA/CD, the adapter waits some time and then returns to sensing the channel. In the following four times, which one is impossible? ( )A 0 bit timesB 512 bit timesC 1024 bit timesD 1028 bit times15.The most common Ethernet technologies are 10BaseT and 100BaseT. “10” and “100” indicate( ).A the maximum length between two adaptersB the minimum length between two adaptersC the transmission rate of the channelD the transmission rate of the node16.The principal components of PPP include but not( ).A framingB physical-control protocolC link-layer protocolD network-layer protocol17.In the following four options, which service can not be provided by switch? ( )A filteringB self-learningC forwardingD optimal routing18.In the following four services, which one was be required in PPP? ( )A packet framingB error detectionC error correctionD multiple types of link19.The ability to determine the interfaces to which a frame should be directed, and then directing the frame to those interfaces is( ).A filteringB forwardingC self-learningD optimal routing20.In ( ) transmission(s), the nodes at both ends of a link may transmit packets at the same time.A full-duplexB half-duplexC single-duplexD both full-duplex and half-duplex21.Consider the data D is 01110010001, if use even parity checking approach, the parity bit is( ① ), if use odd parity checking approach, the parity bit is( ② ). ( )A ①0 ②1B ①0 ②0C ①1 ②1D ①1 ②022.In the following four descriptions about parity checks, which one is correct? ( )A Single-bit parity can detect all errors.B Single-bit parity can correct one errors.C Two-dimensional parity not only can detect a single bit error, but also can correct that error.D Two-dimensional parity not only can detect any combination of two errors, but also can correct them.23.MAC address is ( ) bits long.A 32B 48C 128D 6424.Wireless LAN using protocol ( ).A IEEE 802.3B IEEE 802.4C IEEE 802.5D IEEE 802.1125.The following protocols are belonging to multiple access protocols except for ( ).A channel partitioning protocolsB routing protocolsC random access protocolsD taking-turns protocols26.Which of the following is not belonging to channel partitioning protocols? ( )A CSMAB FDMC CDMAD TDM27.In the following four descriptions about CSMA/CD, which one is not correct? ( )A A node listens to the channel before transmitting.B If someone else begins talking at the same time, stop talking.C A transmitting node listens to the channel while it is transmitting.D With CSMA/CD, the collisions can be avoided completely.28.( ) provides a mechanism for nodes to translate IP addresses to link-layer address.A IPB ARPC RARPD DNS29.A MAC address is a ( )address.A physical-layerB application-layerC link-layerD network-layer30.Which of the following is correct? ( )A No two adapters have the same MAC address.B MAC broadcast address is FF-FF-FF-FF-FF-FF.C A portable computer with an Ethernet card always has the same MAC address, no matter where the computer goes.D All of the above31.In the following four descriptions, which one is not correct? ( )A ARP resolves an IP address to a MAC address.B DNS resolves hostnames to IP addresses.C DNS resolves hostnames for hosts anywhere in the Internet.D ARP resolves IP addresses for nodes anywhere in the Internet.32.In the LAN, ( )protocol dynamically assign IP addresses to hosts.A DNSB ARPC DHCPD IP33.DHCP protocol is a four-step process: ①DHCP request. ②DHCP ACK. ③DHCP server discovery. ④DHCP server offer(s). The correct sequence is ( )A ①②③④B ③②①④C ③④①②D ①④③②34.In the Ethernet frame structure, the CRC field is ( )bytes.A 2B 4C 8D 3235.In the Ethernet frame structure, the Data field carries the ( ).A IP datagramB segmentC frameD message36.In the following four descriptions, which one is not correct? ( )A Ethernet uses baseband transmission.B All of the Ethernet technologies provide connection-oriented reliable service to the network layer.C The Ethernet 10Base2 technology uses a thin coaxial cable for the bus.D The Ethernet 10BaseT technology uses a star topology.37.Ethernet’s multiple access protocol is ( ).A CDMAB CSMA/CDC slotted ALOHAD token-passing protocol38.In the following four descriptions about CSMA/CD, which one is not correct? ( )A An adapter may begin to transmit at any time.B An adapter never transmits a frame when it senses that some other adapter is transmitting.C A transmitting adapter aborts its transmission as soon as it detects that another adapter is also transmitting.D An adapter retransmits when it detects a collision.39.Which of the following descriptions about CSMA/CD is correct? ( )A No slots are used.B It uses carrier sensing.C It uses collision detection.D All of the above.40.The Ethernet 10BaseT technology uses( )as its physical media.A fiber opticsB twisted-pair copper wireC coaxial cableD satellite radio channel41.For 10BaseT, the maximum length of the connection between an adapter and the hub is ( )meters.A 100B 200C 500D 1042.A ( )is a physical-layer device that acts on individual bits rather than on frames.A switchB hubC routerD gateway43.A hub is a ( )device that acts on individual bits rather than on frames.A physical-layerB link-layerC network-layerD ransport-layer44.A switch is a( )device that acts on frame.A physical-layerB link-layerC network-layerD transport-layer45.In the following four descriptions, which one is not correct? ( )A Switches can interconnect different LAN technologies.B Hubs can interconnect different LAN technologies.C There is no limit to how large a LAN can be when switches are used to interconnect LAN segments.D There is restriction on the maximum allowable number of nodes in a collision domain when hubs are used to interconnect LAN segments.46.The ability to determine whether a frame should be forwarded to some interface or should just be dropped is ( ).A f ilteringB f orwardingC s elf-learningD o ptimal routing47.Which of the following devices is not a plug and play device? ( )A hubB routerC switchD repeater48.Which of the following devices is not cut-through device? ( )A hubB routerC switchD repeater49.In the following four descriptions, which one is not correct? ( )A Switches do not offer any protection against broadcast storms.B Routers provide firewall protection against layer-2 broadcast storms.C Both switches and routers are plug and play devices.D A router is a layer-3 packet switch, a switch is a layer-2 packet switch. 50.Which device has the same collision domain? ( )A HubB SwitchC RouterD Bridge51.IEEE802.2 protocol belong to ( )layerA networkB MACC LLCD physical52.IEEE802.11 protocol defines ( )rules.A Ethernet BusB wireless WANC wireless LAND Token Bus53.In data link-layer, which protocol is used to share bandwidth? ( )A SMTPB ICMPC ARPD CSMA/CD54.When two or more nodes on the LAN segments transmit at the same time, there will be a collision and all of the transmitting nodes well enter exponential back-off, that is all of the LAN segments belong to the same( ).A collision domainB switchC bridgeD hub55.( )allows different nodes to transmit simultaneously and yet have their respective receivers correctly receive a sender’s encoded data bits.A CDMAB CSMAC CSMA/CDD CSMA/CA56.Because there are both network-layer addresses (for example, Internet IP addresses) and link-layer addresses (that is, LAN addresses), there is a need totranslate between them. For the Internet, this is the job of ( ).A RIPB OSPFC ARPD IP57.PPP defines a special control escape byte, ( ). If the flag sequence, 01111110 appears anywhere in the frame, except in the flag field, PPP precedes that instance of the flag pattern with the control escape byte.A 01111110B 01111101C 10011001D 1011111058.The device ( ) can isolate collision domains for each of the LAN segment.A modemB switchC hubD NIC59.In the following four descriptions about PPP, which one is not correct? ( )A PPP is required to detect and correct errors.B PPP is not required to deliver frames to the link receiver in the same order in which they were sent by the link sender.C PPP need only operate over links that have a single sender and a single receiver.D PPP is not required to provide flow control.60.In the PPP data frame, the( ) field tells the PPP receivers the upper-layer protocol to which the received encapsulated data belongs.A flagB controlC protocolD checksum61.PPP’s link-control protocols (LCP) accomplish ( ).A initializing the PPP linkB maintaining the PPP linkC taking down the PPP linkD all of the above62.The PPP link always begins in the ( ) state and ends in the ( ) state. ( )A open, terminatingB open, deadC dead, deadD dead, terminating63.For( ) links that have a single sender at one end of the link and a single receiver at the other end of the link.A point-to-pointB broadcastC multicastD all of the above64.With ( )transmission, the nodes at both ends of a link may transmit packets at the same time.A half-duplexB full-duplexC simplex(单工)D synchronous65.With ( ) transmission, a node can not both transmit and receive at the same time.A half-duplexB full-duplexC simplex(单工)D synchronous66.Which of the following functions can’t be implemented in the NIC? ( )A encapsulation and decapsulationB error detectionC multiple access protocolD routing67.Which of the following four descriptions is wrong? ( )A The bus interface of an adapter is responsible for communication with the adapter’s parent node.B The link interface of an adapter is responsible for implementing the link-layer protocol.C The bus interface may provide error detection, random access functions.D The main components of an adapter are the bus interface and the link interface. 68.For odd parity schemes, which of the following is correct? ( )A 011010001B 111000110C 110101110D 00011011069.( )divides time into time frames and further divides each time frame into N time slots.A FDMB TMDC CDMAD CSMA70.With CDMA, each node is assigned a different ( )A codeB time slotC frequencyD link71.Which of the following four descriptions about random access protocol is not correct? ( )A A transmission node transmits at the full rate of the channelB When a collision happens, each node involved in the collision retransmits at once.C Both slotted ALOHA and CSMA/CD are random access protocols.D With random access protocol, there may be empty slots.72.PPP defines a special control escape byte 01111101. If the data is b1b201111110b3b4b5, the value is( )after byte stuffing.A b1b20111110101111110b3b4b5B b1b20111111001111101b3b4b5C b5b4b30111111001111101b2b1D b5b4b30111110101111110b2b173.MAC address is in ( ) of the computer.A RAMB NICC hard diskD cache74.Which of the following is wrong? ( )A ARP table is configured by a system administratorB ARP table is built automaticallyC ARP table is dynamicD ARP table maps IP addresses to MAC addresses75.NIC works in ( )layer.A physicalB linkC networkD transport76.In LAN, if UTP is used, the common connector is( ).A AUIB BNCC RJ-45D NNI77.The modem’s function(s) is(are) ( ).A translates digital signal into analog signalB translates analog signal into digital signalC both translates analog signal into digital signal and translates digital signal into analog signalD translates one kind of digital signal into another digital signal78.( )defines Token-Ring protocol.A IEEE 802.3B IEEE 802.4C IEEE 802.5D IEEE 802.279.( )defines Token-Bus protocol.A IEEE 802.3B IEEE 802.4C IEEE 802.5D IEEE 802.280.( ) defines CSMA/CD protocol.A IEEE 802.3B IEEE 802.4C IEEE 802.5D IEEE 802.281.The computer network that concentrated in a geographical area, such as in a building or on a university campus, is ( )A a LANB a MANC a WAND the Internet82.The MAC address is ( ) bits long.A 32B 48C 128D 25683.Which of the following four descriptions about MAC addresses is wrong? ( )A a MAC address is burned into the adapter’s ROMB No two adapters have the same addressC An adapter’s MAC address is dynamicD A MAC address is a link-layer address84.Which of the following four descriptions about DHCP is correct? ( )A DHCP is C/S architectureB DHCP uses TCP as its underlying transport protocolC The IP address offered by a DHCP server is valid foreverD The DHCP server will offer the same IP address to a host when the host requests an IP address85.The ( )field permits Ethernet to multiplex network-layer protocols.A preambleB typeC CRCD destination MAC address86.For 10BaseT, the maximum length of the connection between an adapter and the hub is ( ) meters.A 50B 100C 200D 50087.An entry in the switch table contains the following information excepts for ( )A the MAC address of a nodeB the switch interface that leads towards the nodeC the time at which the entry for the node was placed in the tableD the IP address of a node88.Consider the 4-bit generator , G is 1001, and suppose that D has the value 101110000. What is the value of R?89.Consider the following graph of the network. Suppose Host A will send a datagram to Host B, Host A run OICQ on port 4000, Host B run OICQ on port 8000. All of ARP tables are up to date. Enumerate all the steps when message “Hello” is sent from host A to host B.。

《计算机网络》考题(英文选择题)

《计算机网络》考题(英文选择题)

《计算机⽹络》考题(英⽂选择题)Computer Networks – Exam1 Short questionsFor each question, please circle a single best answer.1.In the CSMA/CD protocol, what condition on the transmission delay T trans and thepropagation delay T prop has to be satisfied to guarantee that a node always detects a collision?A. T trans > T propB. T trans > 2T prop CORRECTC. T trans < T propD. 2T trans < T prop2.Alice and Bob communicate in an alphabet that has L letters. They use a monoalphabeticsubstitution cipher with key K. Assume that Trudy obtains a plaintext m and thecorresponding ciphertext c. Under what conditions can Trudy recover the key K completely?A. m contains at least 1-L unique letters. CORRECTB. Lm≥.C. Km≥.D. m is not empty.3.The WiMaX protocol:A. provides the maximum available data rate over a wireless channel.B. uses unlicensed spectrum, such as WiFi.C. provides a mechanism for scheduling. CORRECTD. All of the above options are correct.4.Two hosts simultaneously send data through a link of capacity 1Mbps. Host A generates datawith a rate of 1Mbps and uses TCP. Host B uses UDP and transmits a 100bytes packet every 1ms. Which host will obtain higher throughput?A. Host A.B. Host B. CORRECTC. They obtain roughly the same throughput.D. They experience congestion collapse and negligible throughput.5.What is the theoretical upper-bound on the number of simultaneous TCP/IPv4 connectionsthat a host with a single IP address can handle? (Ignore memory limitations.)B. 232C. 264CORRECTD. unlimited6.Host A sends a TCP segment (Seq = 43, ACK = 103), to which host B replies with a TCP segment (Seq = 103, ACK = 57). The payload of the first TCP segment isA. 14 bytes long. CORRECTB. 43 bytes long.C. 46 bytes long.D. 57 bytes long.E. 60 bytes long.7.The Distance-Vector algorithm is not:A. iterative.B. asynchronous.C. distributed.D. used in RIP.E. None of the above. CORRECT8.Longest prefix matching is used:A. in routers to know on which link interface to forward packets. CORRECTB. in classless addressing to use the address space more efficiently than in classful addressing.C. by NAT to increase the available address space in home networks.D. to assign subnet masks.E. None of the above.9.An authoritative DNS server knows a top-level domain server via:A. hostname.B. IP address. CORRECTC. canonical hostname.D. alias.E. domain.10.A user requests aWeb page that consists of some text and 3 images. The browser’s cache is empty. For this page, the client’s browser:A. sends 1 http request message and receives 1 http response messages.B. sends 1 http request message and receives 3 http response messages.C. sends 1 http request message and receives 4 http response messages.D. sends 3 http request messages and receives 3 http response messages.11.What is the advantage of using a layered model of networking?A. Simplified the networkB. For the purpose of standardizationC. Divides the complexity of internetworking into discrete, more easily learned operation subsetsD. All of the above CORRECT12.What is the name of protocol data unit(PDU)at the network layer of the OSI reference model?A. TransportB. FrameC. Packet CORRECTD. Segment13.Which is true when a broadcast is sent out in an Ethernet 802.3 LAN?A. The broadcast is sent only to the default gateway.B. The broadcast is sent only to the destination hardware address in the broadcast.C. The broadcast is sent to all devices in the collision domain. CORRECTD. The broadcast is sent to all devices in the broadcast domain.14.Segmentation of a data stream happens at which layer of the OSI model?A.PhysicalB.Data Link/doc/ee7d8dd65022aaea998f0fd2.html workD.Transport CORRECT15.Which of following international standard defines for Fast Ethernet?A.IEEE 802.3B.IEEE 802.3zC.IEEE 802.3u CORRECTD.IEEE 802.3ae16.What does the Data Link layer use to find hosts on a local network?A.Logical network addressesB.Port numbersC.Hardware addresses CORRECTD.Default gateways17.What were the key reasons the ISO released the OSI model?A.To allow companies to charge more for their equipmentB.To help vendors create interoperable network devices CORRECTC.To help vendors create and sell specialized software and hardware18.What is used at the Transport layer to stop a receiving host’s buffer from overflowing?A.SegmentationB.PacketsC.AcknowledgmentsD.Flow control CORRECT19.When data is encapsulated, which is the correct order?A.Data,frame,packet,segment,bitB.Segment,data,packet,frame,bitC.Data,segment,packet,frame,bit CORRECTD.Data,segment,frame,packet,bit20.What does the term“Base”indicate in 100Base-TX?A.The maximum distanceB.The type of wiring usedC.A LAN switch method using half duplexD.A signaling method for communication on the network CORRECT21.What is the maximum distance of 100Base-T?A.100 feetB.1000 feetC.100 meters CORRECTD.1000 meters22.Which of the following would describe a transport layer connection that would ensure reliable delivery?A.RoutingB.Acknowledgments CORRECTC.SwitchingD.System authentication23.Which of the following is not considered a reason for LAN congestion?A.Low bandwidthB.Too many users in a broadcast domainC.Broadcast stormsD.Routers CORRECT24.Which of the following are two basic types of dynamic routing?A.Static and defaultB.TCP and UDP exchangeD.None of the above25.If your LAN network is currently congested and you are using only hubs in your network,what would be the BEST solution to decrease congestion on your network?A.Cascade your hubs.B.Replace your hubs with switches. CORRECTC.Replace your hubs with routers.D.Add faster hubs.26.What technology is a used by most switches to resolve topology loops and ensure that data flows properly through a single network path?A.RIPB.STP CORRECTC.IGRPD.Store-and-forward27.Which of the following is one of the characteristics of IP?A.reliable and connectionlessB.unreliable and connectionless CORRECTC.reliable and connection-orientedD.unreliable and connection-oriented28.What is the valid host range for subnet 172.16.10.16(Mask 255.255.255.240)?A.172.16.10.20 through 172.16.10.22B.172.16.10.16 through 172.16.10.23C.172.16.10.17 through 172.16.10.31D.172.16.10.17 through 172.16.10.30 CORRECT29.What range of addresses can be used in the first octet of a Class B network address?A.1–126B.128–190C.128–191 CORRECTD.129–19230.Which of the following is not true?A.IP is connectionless and provides routing.B.ARP is used to find an IP address of a host. CORRECTC.UDP is connectionless.D.TCP is connection oriented.31.Which class of IP address provides a maximum of only 254 host addresses per network ID?B.Class BC.Class C CORRECTD.Class D32.Which protocol tool use ICMP?A.TelnetB.Ping CORRECTC.ARPD.FTP33.Which of the following is an IEEE standard for frame tagging?A.802.1XB.802.3ZC.802.1QD.802.3U CORRECT34.A client will use____to send emails to mail-server.A.POP3B.SMTP CORRECTC.TELNETD.FTP35.Which protocol used in PPP allows multiple Network layer protocols to be used during a connection?A.LCPB.NCP CORRECTC.HDLCD.X.2536.When too many packets are present in the subnet, performance degrades. What is this situation called?A.dead lockB.congestion CORRECT/doc/ee7d8dd65022aaea998f0fd2.html work fault/doc/ee7d8dd65022aaea998f0fd2.html work busy37.Which language can be used to realize the client-side dynamic web page generation?A.CGIB.ASP CORRECTC.JavaScript38.The two-wire connections between each subs criber’s telephone and the end office are known in the trade as the____.A.trunkB.local loopC.linkD.switch CORRECT39.When web page is transmitted over SSL, the protocol used is_____.A.HTTPB.SHTTPC.HTTPS CORRECTD.SSL40.Nyquist proved that if an arbitrary signal has been run through a low-pass filter of bandwidthH, the filtered signal can be completely reconstructed by making only_____(exact)samples per secondA.HB.0.5HC.2H CORRECTD.4H41.To convert a binary message to an ASCII message in email system, we can useencoding, which break up groups of 24 bits into four 6-bit units, with each unit being sent asa legal ASCII character. (Ref in page 262)A.base64 CORRECTB.quoted-printableC.SMTPD.POP342.A CRC generator polynomial is G(x)=X8+X5+X2+l.How many bits will the checksum be?A.7B.8 CORRECTC.9D.1043.If the length of sequence is 4 bits, the maximum sending window size should be____.A.13B.14C.15 CORRECTD.1644.In 802.11, to solve the_______station problem and the hidden station problem,we can useA. faultB.mobileC.exposed CORRECTD.wireless45.If the congestion window size is 20KB, and the receive window size is 30KB,what is themaximum bytes can the TCP entity transmit?A.20KB CORRECTB.30KBC.50KBD.10KB46.Port numbers below________are called well-known ports and are reserved for standardservices.A.256B.1024 CORRECTC.4096D.100047.________, which are overlay networks on top of public networks but with most of theproperties of private network.A.PBXB.VPN CORRECTC.CDMA 1XD.GPRS48.The problem of running out of IP addresses is not a theoretical problem that might occur atsome point in the distant future. Some people felt that a quick fix was needed for the short term. This quick fix came in the form of____________________.A.IP6B.DHCPC.RARPD.NAT CORRECT49.Public-key algorithms have the property that_______keys are used for encryption anddecryption and that the decryption key cannot be derived from the encryption key.These properties make it possible to publish the public key.A.one timeB.randomC.same50.The main public-key algorithm is___________which derives its strength from the fact that itis very difficult to factor large numbers.A.DESB.AESC.MD5D.RSA CORRECT51.Various schemes have been devised for digital signatures, using both symmetric-key and________-key algorithms.A.public CORRECTB.privateC.one timeD.one way52.Often, authentication is needed but secrecy is not, based on the idea of a one-way hashfunction that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string. This hash function, MD, often called a________.A.message digest CORRECTB.packet-switchedC.message-detectD.mini data53.URL(Uniform Resource Locator)have three parts: the________, the DNS name of themachine on which the page is located, and a local name uniquely indicating the specific page.A.protocol CORRECTB.addressC.port number/doc/ee7d8dd65022aaea998f0fd2.html54.HTTP1.1, which supports________connections. With them, it is possible to establish a TCPconnection, send a request and get a response, and then additional requests and get additional response.A.one timeB.persistent CORRECTC.stop and waitD.one-way55._______, when it is used, a bad frame that is received is discarded, but the good framesreceived after it are buffered.A.selective repeatD.stop and wait56.How does the FDM multiplexing schemes work like?A.each user having exclusive possession of some band CORRECTB.each user take turns, periodically getting the entire bandwidth for a litter burst of timeC.each user transmit over the entire frequency spectrum all the time with different codingD.each user transmit over a shared fiber using different wavelength57.When we use a modem, which use 16 phases signal to modulation, then how much can we get the maximum data rate in a 2400 baud channel(in noiseless channel)?A.400bpsB.2400bpsC.9.6kbps CORRECTD.14.4kbps58.______is a small java program that has been compiled into binary instruction running in JVM, and can be embedded into HTML pages, interpreted by JVM-capable browsers.A.JavaScriptB.JavaBeanC.Applet CORRECTD.JSP59.Which of the following best describes the function of the OSI reference model’s transport layer?A.It sends data by using flow control CORRECTB.It provides the best path for deliveryC.It determines network addressesD.It provides error-correcting60.What is the most efficient subnet mask to use on point-to-point WAN links?A.255.255.255.0B.255.255.255.224C.255.255.255.252 CORRECTD.255.255.255.248*************************61.Given the cutoff frequency is 3000Hz, the bit rate b=9600 bits/s, then the time required to send 8 bits 1 bit at a time will be 8/b sec, so the number of the highest harmonic passed through isA. 1C. 2.5D. 2062.If two codewords are a Hamming distance 2d+1 apart, it will require single-bit errorsto convert one into the other. Error-correcting can be done while bit-errors are atmost .A.2d, d+1B. 2d, dC.2 d+1, d CORRECTD. None of the above63.For sliding window protocol using go back N, supposing the sender window’s size is 16, then at most frames may be outstanding at any instant.A. 0B. 1C. 15 CORRECTD. 1664.If the physical line is poor, which of the following protocols may be work better?A. Stop-and -WaitB. One-Bit Sliding Window ProtocolC. Sliding Window Protocol Using Go Back ND. Sliding Window Protocol Using Selective Repeat CORRECT65.Services provided by Ethernet are unreliable. If the destination station receive a error data frame, it 。

计算机网络双语试题及答案

计算机网络双语试题及答案

计算机网络双语试题及答案一、选择题(共20题,每题2分,共40分)1. 当使用HTTP协议进行通信时,下列哪个是无连接的协议?A. TCPB. IPC. UDPD. FTP2. 在计算机网络中,IP地址的作用是什么?A. 标识主机在网络中的唯一地址B. 实现数据的可靠传输C. 进行主机之间的通信D. 提供远程访问服务3. 下列哪个不属于网络拓扑结构的类型?A. 总线型拓扑B. 环形拓扑C. 星型拓扑D. 布线型拓扑4. 在TCP/IP协议中,下列哪个协议用于将IP地址转换为物理地址?B. DHCPC. FTPD. ICMP5. 在计算机网络中,HTTP和HTTPS协议之间的区别是?A. HTTP使用明文传输,HTTPS使用加密传输B. HTTP使用UDP传输,HTTPS使用TCP传输C. HTTP使用IP地址,HTTPS使用域名D. HTTP使用GET请求,HTTPS使用POST请求6. 某计算机的IP地址是192.168.0.1,子网掩码是255.255.255.0,那么该计算机所在的网络号是?A. 192.168.0B. 192.168.0.1C. 192.168.0.255D. 192.168.0.07. 在计算机网络中,下列哪个协议用于将域名解析为IP地址?A. DNSB. FTPC. DHCP8. 在TCP/IP协议中,下列哪个协议用于控制数据传输的可靠性?A. ICMPB. UDPC. FTPD. TCP9. 在计算机网络中,什么是反向代理服务器(Reverse Proxy Server)?A. 将外部网络请求转发给内部服务器的服务器B. 将内部网络请求转发给外部服务器的服务器C. 将HTTP请求转发给HTTPS服务器的服务器D. 将HTTPS请求转发给HTTP服务器的服务器10. 在计算机网络中,下列哪个协议用于电子邮件的发送和接收?A. SMTPB. POP3C. HTTPD. FTP11. 在计算机网络中,下列哪个协议用于文件传输?B. SMTPC. UDPD. TCP12. 以下哪个不是IPv6地址的特点?A. 128位长度B. 冒号分隔的十六进制C. 有固定的网络号和主机号D. 全球唯一的地址13. 在计算机网络中,下列哪个技术不属于无线局域网技术?A. Wi-FiB. BluetoothC. NFCD. 4G14. 在网络中,下列哪个设备用于将不同网段的数据转发到目的主机?A. 集线器B. 路由器D. 网关15. 下列哪个网络拓扑结构具有较高的可容错性和可拓展性?A. 星型拓扑B. 总线型拓扑C. 环形拓扑D. 树型拓扑16. 在计算机网络中,下列哪个协议用于互联网上的主机进行网络配置?A. DHCPB. DNSC. HTTPD. FTP17. 在TCP/IP协议中,下列哪个协议用于检测并纠正数据传输中的错误?A. TCPB. ARPC. ICMPD. UDP18. 下列哪个是网络安全的常见攻击方式之一?A. DDoS攻击B. 数据库攻击C. 剪贴板攻击D. 社会工程学攻击19. 下列哪个不是局域网(LAN)的特点?A. 覆盖范围较小B. 速度较快C. 价格较高D. 结构较简单20. 在计算机网络中,下列哪个协议用于向局域网中的所有主机广播消息?A. UDPB. TCPC. DHCPD. ICMP二、问答题(共5题,每题10分,共50分)1. 请简要介绍HTTP协议的工作原理。

计算机网络试卷及答案-英文版

计算机网络试卷及答案-英文版

HUST Examination Answer SheetCourse: Computer Networks (closed-book exam) Jan.2014 Department of Electronics and Information EngineeringSolution[Question 1] Network architecture(1) Draw the architecture diagrams of ISO/OSI reference model and TCP/IP network. (2) State the differences between the two architectures.(3) Mark the names of data unit and network equipment in the bottom 4 layers of ISO/OSI diagram.Solution:(1)ISO/OSI reference model TCP/IP modelDifferences:a) TCP/IP model is the actual architecture in the Internet, while OSI model is a theoreticalarchitecture.b) TCP/IP model does not imply strict layering, while OSI model implies strict layering. c) In TCP/IP model, IP serves as the focal point for the architecture.d) TCP/IP model allows for arbitrarily many different network technologies , ranging fromEthernet to wireless to single point-to-point links.e) TCP/IP model emphasize implementations of proposed protocols. (2)Physical : bit, repeater or hubData link : frame, Ethernet switch or bridge Internet : packet, routerTransport : message, gateway[Question 2] Principles of network designSelect ONE of the following principles, tell its main ideas and provide an example. (1) Keep it simple and stupid(2) Complex edge and simple core (3) Smart sender and dumb receiverSolution:(1) KISS: Keep It Simple and StupidIt means that you should make things simple in the designing. One example following it : Ethernet(2) Complex edge and simple coreIt means that the hosts are very complex and have many functions while the nodes are very simple and have few functions.One example following it : The design of router, or the functions of TCP and IP(3) Smart sender and dumb receiverIt means that the function of sender is more complex than that of the receiver, which is help to improve the robustness and performance of communication protocol. One example following it: The flow control of TCP protocol[Question 3] Error detection(1) Tell the main idea of error detection and error correction in communication.(2) Given the CRC polynomial x 4 + x 3 + 1, if the original message is 10110011010, what is the CRC message to send?(3) Suppose the first bit of the message in (2) is inverted due to the noise in transmission. How can the receiver detect it via CRC verification?Solution:(1)1087431()M x x x x x x x =+++++, 43()1C x x x =++. So k=4.a) Multiply M(x) by 2kto get 141211875()T x x x x x x x =+++++,b) Then divide T(x) by C(x) to get the remainder 0000.c) The message that should be transmitted is 101100110100000.(2)The message received is 001100110100000.Divide it by C(x), then the remainder is 1100.So it is not divisible by C(x).So the receiver knows that an error has occurred.(1) What are the essential components to realize reliable transmission?(2) Suppose two computers are communicated via Stop-and-wait protocol. The link bandwidth is 5kbps, and the one-way propagation delay is 20ms. To reach 80% or higher link utilization, what is the minimal frame size for this communication?(3) If it is upgraded to Sliding-Window protocol. To reach the same goal with (2), what is the minimal window size, how many bits are required to describe the frame sequence in window? (Suppose the frame size is 1 or 100Byte)Solution:(1)ACK, and timerActual_throughput = Data / Total_DelayTotal_Delay = RTT + Data / BWLink_Utilization = 100 * Actual_throughput / BWSo: Data/throughput = RTT + Data/BW(BW/throughput - 1) Data = BW*RTTData = BW*RTT/(1/Utilization -1)For the stop-and-wait protocol, for each RTT only one frame is sent,Thus Frame_size = Data = BW*RTT/(1/Utilization - 1) = 5kbps * 40ms / (1/0.8 - 1)= 200 bit / 0.25 = 800 bit = 100 ByteIf the students ignore the data transmission delay, their answer isframe_size = BW*RTT*Utilization = 5000 bit/sec * 40 / 1000 sec * 0.8 = 160 bit = 20 ByteIn this case, at least -2 score.(3)For the sliding-window protocol, in each RTT the data window can be transmitted at most.Thus Window_size = Data = BW*RTT/(1/Utilization - 1) = 5kbps * 40ms / (1/0.8 - 1)= 200 bit / 0.25 = 800 bit = 100 ByteIf the frame size is 100Byte, 1 frames are allowed.To indicate the frames in both sides of sender and receiver, the sequence number should describe 2 frames, thus the [log2(2) ]=1 bitIf the students ignore the data transmission delay, their answer iswindow_size = BW*RTT*Utilization = 5000 bit/sec * 40 / 1000 sec * 0.8 = 160 bit = 20 ByteIf the frame size is 100Byte, 1 frames are allowed.To indicate the frames in both sides of sender and receiver, the sequence number should describe 2 frames, thus the [log2(2) ]=1 bitIn this case, at least -2 score.(1) What is the main idea of CSMA/CD (Carrier Sense Multiple Access/Collision Detection) in traditional Ethernet? Can it be deployed for wireless local network, why?(2) Suppose one traditional Ethernet has 1km cable, the signal propagation speed is 2*105km/s, and the transmission rate is designed to be 100Mbps. What is the minimal frame size to support carrier sensing?Solution:(1) the main idea of CSMA/CD include two parts. One is carrier sensing, which means the node should detect the channel before sending any data. If the node finds the channel is idle, it begins to transmit. Otherwise, the node stop for next round. The second issues is collision detection, which means the node should detect the channel in the duration of its data transmission. If the node finds the channel become busy, or in other word, there is a collision, it should stop transmitting immediately.CSMA/CD cannot be deployed in wireless LAN, because the wireless radio transmitter and receiver can not work in dual mode. The wireless node cannot detect collision when it is transmitting data.(2)the minimal frame should be transmitted throughout the whole traditional Ethernet.Thus t = frame_size / transmit_rate = 2 * cable_length / prop_speed.Frame_size = 100 * 106 bits/sec * 2 * 103 m / (2 * 108)m/sec = 1000 bits = 125 Byte[Question 6] Switched network(1) What are the differences between circuit switching and packet switching?(2) For the following linear topology network, each link has 2ms propagation delay and 4 Mbps bandwidth.A B C DIf we use circuit switching, circuit setup requires a 1KB message to make one round-trip on the path, which incurs a 1ms delay at each switch after the message has been completely received. Then we can send the file as one contiguous bit stream. What is the delay for circuit switching to transmit n-byte from A to D?(3) If we use packet switching in the network of (2), we can break the file into 1KB packets, which has 24byte header and 1000byte payload. The switch takes 1ms process delay after receiving the packet, and then sent it continuously. What is the condition for packet switching to have less delay performance than circuit switching?Solution:(1)(2)T pkt = Packet_Size / Bandwidth = 1 KB / 4Mbps = 1024 *8 / (4 * 106) = 2.048 ms T p = 2 ms, T s = 1 ms,T t = n B / 4MbpsIn circuit switching, Total time duration:D = Singling_Delay + Transmission_Delay = 2 * Packet_Duration + Transmission_Delay = 2 * (T pkt * 2 + T p * 3 + T s * 2 + T pkt ) + (T p * 3 + T t ) = T pkt * 6 + T p * 9 + T s * 4 + T tThus, D = 2.048 * 6 + 2 * 9 + 1 * 4 + n * 8 bits / 4Mbps = 34.288 (ms) + 2n (us)(3)Main ideaThe reliability provided by endhost The reliability provided by thenetwork Information in packet Every packet has its dest-addrin header Every packet has its temp VCIlocally Forwarding action inswitch Every packet was treatedindependentlyThe packets are processed inthe manner of VCPackets received indestinationNot in sequenceIn sequenceT pkt = Packet_Size / Bandwidth = 1 KB / 4Mbps = 1024 *8 / (4 * 106) = 2.048 msT p = 2 ms,T s = 1 ms,T t = 1.024 * n B / 4MbpsIn packet switching, Total time duration:D = Delay_at_Switch * Switch_Num + Delay_at_last_hop= (T p + T pkt +T s)*2 + (T p + T t )= T pkt * 2 + T p * 3 + T s * 2 + T tThus, D = 2.048 * 2 + 2 * 3 + 1 * 2 + 1.024 * n B / 4Mbps= 12.096 (ms) + 2.048 n (us)In order to make34.288 (ms) + 2n (us) > 12.096 (ms) + 2.048 n (us)Thus 22.192(ms) > 0.048 n(us)n < 22.192 * 1000 / 0.048 = 462333 Byte = 451.5 KB[Question 7] Ethernet Switch(1) What are the differences between hub and switch in Ethernet?(2) Suppose one server and nine clients are connected via hub in 10Mbps Ethernet, what is the maximal bandwidth for the client-server connection?(3) If the hub is upgraded to switch, can the client-server connection obtain more bandwidth? if can, how much is it?Solution:(1)hub works in Layer2, it works as the shared media and relays the frames to all the nodes connecting to hub. Switch works in Layer2, it forwards the frames to the specific node according to the destination address embedded in the frame header.(2)the max bandwidth in client-server connection is 10Mbps/(1+9)= 1Mbps(3)the max bandwidth in client-server connection is 10Mbps/9 = 1.1111MbpsAdditional 0.1111 Mbps is obtained for each connection.[Question 8] Router(1) Somebody says that, ``the only difference between switch and router is that they do switch function based on the address in different layers.’’ Is it correct? Why?(2) If we obtain the following information from one router. What kind of routing protocol does itSolution:(1)it is not fully correct. The part talking about the forwarding function is correct, while it is not the only difference. Another but not the last difference is that, router has more functions on control plane, which do routing and find the paths for packets.(2)The routing protocol is RIP.The routing table is:Destination Next hop Interface192.168.1.0/24 * Fa 0/4192.168.2.0/24 * Fa 0/6192.168.10.0/24 192.168.1.1 Fa 0/4192.168.30.0/24 192.168.2.2 Fa 0/6[Question 9] Routing algorithm(1) State the main differences between distance vector routing and link state routing.(2) For the network given in the following figure, provide the steps of forward search in Dijkstra algorithm for node A finding the shortest path to node ESolution:(1) The idea of distance vector routing is to tell the neighbors about the learned topology to all the nodes in the network. The idea of link state routing is to tell all the nodes in network about the neighborhood topology.Step 1 2 3 4 5 6 7 8 9Confirmed (A,0,-) (A,0,-) (A,0,-)(D,2,D)(A,0,-)(D,2,D)(A,0,-)(D,2,D)(B,4,D)(A,0,-)(D,2,D)(B,4,D)(A,0,-)(D,2,D)(B,4,D)(E,6,D)(A,0,-)(D,2,D)(B,4,D)(E,6,D)(A,0,-)(D,2,D)(B,4,D)(E,6,D)(C,7,D)Tentative (B,5,B)(D,2,D)(B,5,B) (B,4,D)(E,7,D)(E,7,D)(E,6,D)(C,8,D)(C,8,D) (C,7,D)A→E A→D→EA→D→B→EA→D→B→E[Question 10] IP address allocationA company has one C class IP address of 200.1.1.*. It has four departments.(1) If each department has less than 25 computers. Provide a kind of IP address allocation. Give the network address, subnet mask, and the available IP address range for each department. (2) If the four departments have 72, 35, 34, 20 computers respectively. Provide the IP address allocation scheme again.Solution:(1)Since each department has less than 25 computers, even considering the additional two more IP address for gateway and broadcast, the 64-computer subnet is enough for them.One IP address allocation scheme is to even divide the 256 IP addresses into 4 subnets, each subnet allows 64 hosts.Another IP address allocation scheme is to even divide the 256 IP addresses into 4 subnets, each subnet allows 32 hosts.(2) Since one of the department has more requirements than 64, then the even distribution scheme[Question 11] TCP protocol(1) Somebody says that, ``because of the reliable transmission service in layer 2, there is no need to provide such service again within TCP protocol in layer 4’’. Is it correct? Why?(2) State the main rules of TCP connection setup according to the following figure. Explain every word and number in the figure.Solution:(1) It is wrong. TCP is based on the un-reliable IP layer, which only provides best effort service. If TCP wants to provide reliable transmission service, it has to realize this by itself.(2)TCP use three hand-shakes to setup the connection.According to the figure, there are two nodes. The sender is with IP address of 192.168.1.163 and the receiver 192.168.1.165 respectively.●At first, the sender send a request ``SYN’’to the receiver to setup the connection. Thismessage is with the sequence number of 424CF1DC;●Secondly, the receiver reply an acknowledgment message ``SYN/ACK’’ to the sender. Thismessage has two sequence numbers. The seq in the ACK is 424CF1DD, which is to confirm the last ``SYN’’ from sender. The seq in the SYN is 30318555, which is a new message from the receiver.●Thirdly, the sender reply an acknowledgment message ``ACK’’ to the receiver. The seq in theACK is 30318556, which is to confirm the last ``SYN’’ from receiver.In the end, both the sender and receiver knows that the other side is ready for this TCP connection.[Question 12] TCP congestion control(1) Both flow control and congestion control in TCP are realized by window based packet control. How can TCP get the window sizes in these two mechanisms?(2) Assume that TCP implements an extension that allows window sizes much larger than 64 KB. Suppose that you are using this extended TCP over a 1Gbps link with a latency of 150ms. TCP packet size is 1KB, and the max receive window is 1 MB. Suppose there is no real congestion and packet loss in transmission. How many RTTs does it take until slow start opens the send window to 1 MB? How long does it take to send the complete file? ( Suppose file size is 10MB )Solution:(1) In flow control, TCP sender knows the window size by the field of advertise-window replied from the receiver. In congestion control, TCP sender learns the window size adaptively by AIMD( Additive Increase and Multiplicative Decrease) mechanism responding to the packet lossevent.(2)When TCP realizes congestion control mechanism, its effective send window size will be min (CongestionWindow, AdvertizedWindow). In original design of TCP header, the field of AdvertizedWindow is 16 bit, which is 216=26*210=64 KB. So the maximum effective window of original TCP sender is 64KB. The assumption of the first sentence in this question relaxes such constraint for TCP.In slow start, the send window starts from w0=1 packet, which is 1 KB. For each RTT after a successful transmission, the window size will be doubled. After i RTT, it will be 2i * w0. Let 2i * 1KB = 1MB, soi = log2(1MB/1KB) = log2(210) = 10.It will take 10 RTTs to reach 1MB send window.Case 1: if the receiver window remains as 1MBIn the first 10 RTTs, total (1 + 2 + 4 + … + 210) * 1KB has been transmitted.Which is (211 - 1) * 1KB = 2 MB - 1 KB, the rest file is 10MB - (2MB - 1KB) = 8MB + 1KBIn the reset transmission, each RTT can only support 1MB transmission.Thus, additional 9 RTTs are required. Total 19 RTT = 19 * 150ms = 2.85 sCase 2: if the receiver window can be changed.Since there is no congestion and loss, the maximum send window will be the bandwidth * delay for this TCP connection.w max= 1G bps * 150ms = 109 * 150 * 10-3= 150 *106 bit = 18.75 * 106 byte = 17.88 MB.So, this 10 MB file can be transferred before reaching w max. In another word, it can be sent in its slow start phase. Assume x RTT is required to send this file, then:(1 + 2 + 4 + … + 2x) * 1KB ≥ 10 MB2 * 2x–1 ≥ 10 * 1024x ≥ log2(10241) – 1 = 12.3Thus x = 13, it will take 13 RTTs to transfer this file. 13RTT = = sTotal delay = 13RTT + Filesize/BW = 13 * 150ms+ 10MB / 1Gbps =1.95 + 0.08 * 1.024^2=2.03 s11。

计算机网络英文复习题

计算机网络英文复习题

计算机⽹络英⽂复习题、英译汉(10分)1.TCP(Transmission Control Protocol) 传输控制协议2.IP(Internet Protocol) 互联⽹协议3.RFC(Requests for comments) 请求评议4.SMTP(Simple Mail Transfer Protocol) 简单邮件传输协议5.Congestion-control 拥塞控制6.Flow control 流控制7.UDP (User Datagram Protocol) ⽤户数据报协议8.FTP(File Transfer Protocol) ⽂件传输协议9.HTTP( Hyper-Text Transfer Protocol ) 超⽂本传输协议10.TDM 时分复⽤11.FDM 频分复⽤12.ISP(Internet Service Provider) 互联⽹服务提供商13.DSL(Digital Subscriber Line) 数字⽤户线路14.DNS(Domain Name System) 域名系统15.ARQ(Automatic Repeat Request) ⾃动重发请求16.ICMP(Internet Control Message Protocol) ⽹间控制报⽂协议17.AS(Autonomous Systems) ⾃制系统18.RIP(Routing Information Protocol)\ 路由信息协议19.OSPF(Open Shortest Path First) 开放最短路径优先20.BGP (Border Gateway Protocol) 边界⽹关协议21.HFC 光纤同轴电缆混合⽹22.CRC(Cyclic Redundancy Check) 循环冗余检验23.CSMA/CD 带冲突检测的载波侦听多路存取24.ARP 地址解析协议25.RARP 反向地址解析协议26.DHCP 动态主机配置协议27.RTT 循环时间28.IETF(P5)互联⽹⼯程任务组29.URL(P88)统⼀资源定位30.API应⽤程序编程接⼝31.MIME多⽤途互联⽹邮件扩展1. DSL divides the communication link between the home and the ISP into three nonoverlapping frequency bands, a upstream channel is in _A_________.A)50 kHz to 1MHz band B) 1MHz to 2MHz bandC)4 kHz to 50kHz band D) 0 to 4kHz band2. As a data packet moves from the upper to the lower layers, headers are A .A) Added; B) subtracted; C) rearranged; D) modified3. What is the main function of the network layer? DA) node-to-node delivery; B) process-to-process message deliveryC) synchronization; D) updating and maintenance of routingtables4. Which of the following is the default mask for the address 168.0.46.201? BA) 255.0.0.0; B) 255.255.0.0; C) 255.255.255.0; D) 255.255.255.2555.A router reads theaddress on a packet to determine the next hop. AA) IP ; B) MAC; C) source; D)ARP6 .Which device can’t isolates the departme ntal collision domains. AA) Hub; B) switch; C) router; D) A and B7. Input port of a router don’t perform ____D____ functions.A) the physical layer functions B) the data link layer functionsC) lookup and forwarding function D) network management8. HTTP has a mechanism that allows a cache to verify that its objects are up to date. The mechanism is DA) persistent connections B) cookies C) Web Caching D) conditional GET9. A protocol layer can be implemented in ___D_____.A) software B) hardware C) a combination of the software and hardware D) All of the above10. A protocol has three important factors, they are_A______.A)syntax, semantics, order B) syntax, semantics, layerC)syntax, semantics, packet D) syntax , layer, packet11. There are two broad classes of packet-switched networks: datagram networks and virtual-circuit networks. The virtual-circuit networks forward packets in their switches use ___D___.A) MAC addresses B) IP addressesC) e-mail addresses D) virtual-circuit numbers12. TCP service model doesn’t provide ___D_______service.A) reliable transport service B) flow control serviceC) congestion-control service D) guarantee a minimum transmission rate service.13. Usually elastic applications don’t include____B______.A) Electronic mail B) Internet telephony14. A user who uses a user agent on his local PC receives his mail sited in a mail server by using _B___ protocol.A)SMTP B) POP3C)SNMP D) FTP15. Considering sliding-window protocol, if the size of the transmitted window is N and the size of the receiving window is 1,the protocol is BA) stop-and-wait protocol B) Go-Back-N protocolC) selective Repeat protocol D) alternating-bit protocol16. which IP address is effective___B______.A) 202,131,45,61 B) 126.0.0.1C) 192.268.0.2 D) 290.25.135.1217. if IP address is 202.130.191.33, subnet mask is 255.255.255.0,then subnet prefix is__D_____A) 202.130.0.0 B) 202.0.0.0C) 202.130.191.33 D)202.130.191.018.The command Ping s implemented with __B______messagesA) DNS B) ICMPC) IGMP D) RIP19. Which layer-function is mostly implemented in an adapter? __A________A) physical layer and link layer B) network layer and transport layerC)physical layer and network layer D) transport layer and application layer20. If a user brings his computer from Chengdu to Peking, and accesses Internet again. Now, __B_____ of his computer needs to be changed.A) MAC address B) IP addressC) e-mail address D) user address1. .traceroute is implemented with __B____messages.A) DNS B) ICMPC) ARP D) RIP2.A router reads the A address on a packet to determine the next hop.A. IP ;B. MAC;C. source;D.ARP3. There are two broad classes of packet-switched networks: datagram networks andvirtual-circuit networks. The virtual-circuit networks forward packets in their switches use ___D___.A) MAC addresses B) IP addressesC) e-mail addresses D) virtual-circuit numbersA) device interfaces with same subnet part of IP addressB) can’t physically reach each other without intervening a router.C)all of the devices on a given subnet having the same subnet address.D)A portion of an interface’s IP address must be determined by the subnet to which it is connected.5. if IP address is 102.100.100.32, subnet mask is 255.255.240.0,then subnet prefix is___A___A) 102.100.96.0 B) 102.100.0.0C) 102.100.48.0 D) 102.100.112.06 If a user brings his computer from chengdu to beijing, and accesses Internet again. Now,___B__ of his computer needs to be changed.A) MAC address B) IP addressC) e-mail address D) user address7.I nput port of a router don’t perform ____D___ functions.A) the physical layer functions B) the data link layer functionsC) lookup and forwarding function D) network management8.switching fabric is at the heart of a router, switching can be accomplished in a number of ways, donit include_D_A)Switching via memory B)Switching via crossbarC)Switching via a bus D) Switching via buffer9.if a host wants to emit a datagram to all hosts on the same subnet, then the datagram’s destination IP address is ___B__A)255.255.255.0 B) 255.255.255.255C)255.255.255.254 D) 127.0.0.110.The advantage of Circuit switching does not include________.A) small transmission delay B)small Processing costC) high link utilization D)no limited to format of message1.an ARP query sent to __A__A) local network B) all over the Internet.2. .packet-switching technologies that use virtual circuitsinclude__B___:A) X.25, ATM, IP B) X.25, ATM, frame relay.C) IPX, IP, ATM D) IPX, IP, TCP3. In Internet, _D_ protocol is used to report error and provide the information forun-normal cases.A) IP B) TCP C)UDP D) ICMP1.A is a Circuit-switched network.B. Datagram networkC. InternetD. virtual circuit network2.The store-and-forward delay is DA. processing delayB. queuing delayC. propagation delayD. transmission delay3.Which is not the function of connection-oriented service? DA. flow controlB. congestion controlC. error correctionD. reliabledata transfer4.The IP protocol lies in CA. application layerB. transport layerC. network layerD. link layer5.Which of the following is the PDU for application layer __B___A.datagram;B. message;C. frame;D.segment6.bandwidth is described in _B__A) Bytes per second B) Bits per secondC) megabits per millisecond D) centimeters7.A user who uses a user agent on his local PC receives his mail sited in a mail server by using __A__ protocol.A)SMTP B) POP3C)SNMP D) FTP8.As a data packet moves from the lower to the upper layers, headers are B.A)Added; B. subtracted; C. rearranged; D. modified三、填空题(每空1分,共22分 (注意:所有填空题不能写中⽂,否则中⽂答案对的情况1. link-layer address is variously called a LAN address, a MAC address, or a physical address.2 In the layered architecture of computer networking, n layer is the user of n-1 layer and the service provider of n+1 layer.A) n B) n+3 C) n+1 D) n-1四、判断题(每⼩题1分,共10分)1.√The services of TCP’s reliable data transfer founded on the services of theunreliable data transfer.2.√Any protocol that performs handshaking between the communication entitiesbefore transferring data is a connection-oriented service.3.× HOL blocking occur in output ports of router.4.√Socket is globally unique.5.√SMTP require multimedia data to be ASCII encoded before transfer.6.×The transmission delay is a function of the distance between the two routers.7.×IP address is associated with the host or router. SO one device only have one IPaddress.8. √In packet-switched networks, a session’s messages use the resources on demand, and Internet makes its best effort to deliver packets in a timely manner.9. ×UDP is a kind of unreliable transmission layer protocol, so there is not any checksum field in UDP datagram header.10.√Forwarding table is configured by both Intra and Inter-AS routing algorithmIP is a kind of reliable transmission protocol. F8.Forwarding table is configured by both Intra and Inter-AS routing algorithm.T9.Distance vector routing protocol use lsa to advertise the network which router10.RIP and OSPF are Intra-AS routing protocols T11.Packet switching is suitable for real-time services, and offers better sharing ofbandwidth than circuit switching F五、计算题(28 points)1.C onsider the following network. With the indicated link costs, use Dijkstra’s shortest-path algorithm to compute the shortest path from X to all network nodes.2 Given: an organization has been assigned the network number 198.1.1.0/24 and it needs todefine six subnets. The largest subnet is required to support 25 hosts. Please:●Defining the subnet mask; (2分) 27bits or 255.255.255.224●Defining each of the subnet numbers; which are starting from 0# (4分)198.1.1.0/27 198.1.1.32/27 198.1.1.64/27 198.1.1.96/27 198.1.1.128/27 198.1.1.160/27 198.1.1.192/27 198.1.1.224/27●Defining the subnet 2#’s broadcast address.(2分) 198.1.1.95/27Defining host addresses scope for subnet 2#. (2分) 198.1.1.65/27--198.1.1.94/273. Consider sending a 3,000-byte datagram into a link that has an MTU of 1500bytes.Suppose the original datagram is stamped with the identification number 422 .Assuming a 20-byte IP header,How many fragments are generated? What are their characteristics?(10分)。

计算机网络英文题库附答案chater

计算机网络英文题库附答案chater

Chapter 1 Computer Networks and the Internet1.The ( ) is a worldwide computernetwork, that is, a network that interconnectsmillionsofcomputing devices throughout theworld. ppt3 A public InternetB IntranetC switch netD television net2.Which kind of media is not a guidedmedia ( )A twisted-pair copper wireB a coaxial cableC fiber opticsD digital satellite channel3.Which kind of media is a guided media ( )A geostationary satelliteB low-altitude satelliteC fiber opticsD wireless LAN4.The units of data exchanged by a link-layer protocol are called ( ).A FramesB SegmentsC DatagramsD bit streams5.Which of the following optionbelongs to the circuit-switchednetworks ( )A FDMB TDMC VCnetworksD both A and B 6.( )makes sure that neither sideof a connection overwhelms theother side by sending too manypackets too fast.A Reliable data transferB Flow controlC Congestion controlD Handshaking procedure7.( ) means that the switch mustreceive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Store-and-forward transmissionB FDMC End-to-end connectionD TDM8.Datagramnetworksandvirtual-circuit networks differ in that ( ).A datagram networks are circuit-switched networks, and virtual-circuit networks are packet-switched networks.B datagram networks are packet-switched networks, and virtual-circuit networks are circuit-switched networks.C datagram networks use destination addresses and virtual-circuit networks use VC. numbers to forward packets toward their destination.D datagram networks use VC. numbers and virtual-circuit networks use destination addresses to forward packetstoward their destination.9.In the following options, which one is not a guided media ( )A twisted-pairwireB fiber opticsC coaxial cableD satellite10.Processing delay does not include the time to ( ).A examine the packet ’s headerB wait to transmit the packet onto the linkC determine where to direct thepacketD check bit-error in the packet 11.In the following four descriptions, which one is correct ( )A The traffic intensity must begreater than 1.B The fraction of lost packetsincreases as the trafficintensity decreases.C If the traffic intensity isclose to zero, the averagequeuing delay will be close tozero.D If the traffic intensity isclose to one, the averagequeuing delay will be close toone.12.The Internet’s network layer is responsible for movingnetwork-layer packets known as( ) from one host to another.A frameB datagramC segmentD message13.The protocols of various layersare called ( ).A the protocol stackB TCP/IPC ISPD network protocol14.There are two classes ofpacket-switched networks: ( )networks and virtual-circuitnetworks.A datagramB circuit-switchedC televisionD telephone15.Access networks can be looselyclassified into threecategories: residential access,company access and ( ) access.A cabledB wirelessC campusD city areaQuestion 16~17Suppose, a is the average rate at which packets arrive at the queue,R is the transmission rate, and all packets consist of L bits, then thetraffic intensity is ( 16 ), and it should no greater than ( 17 ).16. A LR /aB La /RC Ra /LD LR /a 17.A 2B 1C 0D -118.In the Internet, the equivalentconcept to end systems is ( ).A hostsB serversC clientsD routers19.In the Internet, end systems are connected together by ( ).A copper wireB coaxial cableC communication linksD fiber optics 20.End systems access to the Internet through its ( ). A modemsB protocolsC ISPD sockets21.End systems, packet switches,and other pieces of the Internet, run ( ) that control thesending and receiving ofinformation within theInternet.A programsB processesC applicationsD protocols22.There are many private networks,such as many corporate andgovernment networks, whosehosts cannot exchange messages with hosts outside of the private network. These private networks are often referred to as ( ).A internetsB LANC intranetsD WAN23.The internet allows ( ) runningon its end systems to exchangedata with each other.A clients applicationsB server applicationsC P2P applicationsD distributed applications24.The Internet provides two services to its distributed applications: a connectionlessunreliable service and ()service.A flowcontrolB connection-oriented reliableC congestion controlD TCP25.It defines the format and theorder of messages exchangedbetween two or morecommunicating entities, as wellas the actions taken on thetransmission and/or receipt ofa message or other event. Thesentence describes ( ).A InternetB protocolC intranetD network26.In the following options, which does not define in protocol ( )A the format of messagesexchanged between two or morecommunicating entitiesB the order of messagesexchanged between two or morecommunicating entitiesC the actions taken on thetransmission of a message orother eventD the transmission signals aredigital signals or analogsignals27.In the following options, which is defined in protocol ( )A the actions taken on thetransmission and/or receiptof a message or other event B the objects exchanged between communicating entities C the content in the exchangedmessagesD the location of the hosts28.In the following options, whichdoes not belong to the network edge( )A end systemsB routersC clientsD servers29.In the following options, whichbelongs to the network core ( )A end systemsB routersC clientsD servers30.In the following options, whichis not the bundled with theInternet’sconnection-oriented service( )A reliable data transferB guarantee of thetransmission timeC flow controlD congestion-control31.An application can rely on theconnection to deliver all of itsdata without error and in theproper order. The sentencedescribes ( ). A flow controlB congestion-controlC reliable datatransferD connection-oriented service 32.It makes sure that neither sideof a connection overwhelms theother side by sending too manypackets too fast. The sentence describes ( ). A flow controlB congestion-controlC connection-oriented serviceD reliable data transfer33.It helps prevent the Internetfrom entering a state of gridlock. When a packet switchbecomes congested, its bufferscan overflow and packet loss canoccur. The sentence describes( ).A flowcontrolB congestion-controlC connection-oriented serviceD reliable data transfer 34.TheInternet ’sconnection-oriented service has aname, it is ( ).A TCPB UDPC TCP/IPD IP35.In the following options, which service does not be provided to an application by TCP( )A reliable transportB flow controlC video conferencingD congestion control36.The Internet ’s connectionless service is called ( ).A TCPB UDPC TCP/IPD IP37.In the following options, which does not use TCP( )A SMTPB internet telephoneC FTPD HTTP38.In the following options, which does not use UDP( )A InternetphoneB video conferencingC streamingmultimediaD telnet39.There are two fundamentalapproaches to building a network core, ( ) and packet switching.A electrical current switchingB circuit switchingC data switchingD message switching40.In ( ) networks, the resourcesneeded along a path to provide for communication between the end system are reserved for theduration of the communicationsession.A packet-switchedB data-switchedC circuit-switchedD message-switched41.In ( ) networks, the resources are not reserved; a session’smessages use the resources ondemand, and as a consequence,may have to wait for access tocommunication link.A packet-switchedB data-switchedC circuit-switchedD message-switched42.In a circuit-switched network, if each link has n circuits, foreach link used by the end-to-endconnection, the connection gets( ) of the link’s bandwidthfor the duration of the connection.A a fraction 1/nB allC 1/2D n times43.For ( ), the transmission rateof a circuit is equal to theframe rate multiplied by thenumber of bits in a slot.A CDMAB packet-switched networkC TDMD FDM44.( ) means that the switch mustreceive the entire packetbefore it can begin to transmitthe first bit of the packet ontothe outbound link.A Queuing delayB Store-and-forwardtransmissionC Packet lossD Propagation45.The network that forwardspackets according to host destination addresses is called( ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram46.The network that forwardspackets according tovirtual-circuit numbers iscalled ( ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram47.In the following entries, whichis not a kind of access network( )A residentialaccessB company accessC wirelessaccessD local access48.Suppose there is exactly onepacket switch between a sendinghost and a receiving host. The transmission rates between thesending host and the switch and between the switch and the receiving host are R 1 and R 2,respectively. Assuming that theswitch uses store-and-forwardpacket switching, what is thetotal end-to-end delay to senda packet of length L (Ignorequeuing delay, propagationdelay, and processing delay.) ( ) A L /R 1+L /R 2B L /R 1C L /R 2D none of the above49.The time required to examine thepacket ’s header and determinewhere to direct the packet ispart of the ( ). A queuing delayB processing delayC propagation delayD transmission delay50.The time required to propagatefrom the beginning of the linkto the next router is ( ). A queuing delayB processing delayC propagation delayD transmission delay51.Consider sending a packet of3000bits over a path of 5 links. Eachlink transmits at 1000bps. Queuingdelays, propagation delay and processing delay are negligible. (6 points)(1).Suppose the network is apacket-switched virtual circuitnetwork. VC setup time is seconds.Suppose the sending layers add atotal of 500 bits of header to eachpacket. How long does it take to sendthe file from source to destination(2).Suppose the network is a packet-switched datagram networkand a connectionless service is used.Now suppose each packet has 200 bitsof header. How long does it take tosend the file(3).Suppose that the network is acircuit-switched network. Furthersuppose that the transmission rate of the circuit between source anddestination is 200bps. Assumingsetup time and 200 bits of header appended to the packet, how longdoes it take to send the packetS olution:(1).t=5*(3000+500)/1000+=( 2).t=5*(3000+200)/1000=16s( 3).t=(3000+200)/200+=。

最新计算机网络英文题库(附答案)chapter1word版本

最新计算机网络英文题库(附答案)chapter1word版本

Chapter 1 Computer Networks and the Internet1.The ( ) is a worldwide computer network, that is, a network that interconnects millions of computing devices throughout the world.ppt3A public InternetB IntranetC switch netD television net2.Which kind of media is not a guided media? ( )A twisted-pair copper wireB a coaxial cableC fiber opticsD digital satellite channel3.Which kind of media is a guided media? ( )A geostationary satelliteB low-altitude satelliteC fiber opticsD wireless LAN4.The units of data exchanged by a link-layer protocol are called ( ).A FramesB SegmentsC DatagramsD bit streams5.Which of the following option belongs to the circuit-switched networks? ( )A FDMB TDMC VC networksD both A and B6.( )makes sure that neither side of a connection overwhelms the other side by sending too many packets too fast.A Reliable data transferB Flow controlC Congestion controlD Handshaking procedure7.( ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Store-and-forward transmissionB FDMC End-to-end connectionD TDM8.Datagram networks and virtual-circuit networks differ in that ( ).A datagram networks are circuit-switched networks, andvirtual-circuit networks are packet-switched networks.B datagram networks are packet-switched networks, andvirtual-circuit networks are circuit-switched networks.C datagram networks use destination addresses and virtual-circuitnetworks use VC. numbers to forward packets toward theirdestination.D datagram networks use VC. numbers and virtual-circuit networksuse destination addresses to forward packets toward their destination. 9.In the following options, which one is not a guided media? ( )A twisted-pair wireB fiber opticsC coaxial cableD satellite10.Processing delay does not include the time to ( ).A examine the packet’s headerB wait to transmit the packet onto the linkC determine where to direct the packetD check bit-error in the packet11.In the following four descriptions, which one is correct? ( )A The traffic intensity must be greater than 1.B The fraction of lost packets increases as the traffic intensitydecreases.C If the traffic intensity is close to zero, the average queuing delaywill be close to zero.D If the traffic intensity is close to one, the average queuing delaywill be close to one.12.The Internet’s network layer is responsible for moving network-layer packets known as ( ) from one host to another.A frameB datagramC segmentD message13.The protocols of various layers are called ( ).A the protocol stackB TCP/IPC ISPD network protocol14.There are two classes of packet-switched networks: ( ) networks and virtual-circuit networks.A datagramB circuit-switchedC televisionD telephone15.Access networks can be loosely classified into three categories: residential access, company access and ( ) access.A cabledB wirelessC campusD city areaQuestion 16~17Suppose, a is the average rate at which packets arrive at the queue, R is the transmission rate, and all packets consist of L bits, then the traffic intensity is ( 16 ), and it should no greater than ( 17 ).16. A LR/aB La/RC Ra/LD LR/a17.A 2B 1C 0D -118.In the Internet, the equivalent concept to end systems is ( ).A hostsB serversC clientsD routers19.In the Internet, end systems are connected together by ( ).A copper wireB coaxial cableC communication linksD fiber optics20.End systems access to the Internet through its ( ).A modemsB protocolsC ISPD sockets21.End systems, packet switches, and other pieces of the Internet, run ( ) that control the sending and receiving of information within theInternet.A programsB processesC applicationsD protocols22.There are many private networks, such as many corporate and government networks, whose hosts cannot exchange messages withhosts outside of the private network. These private networks are often referred to as ( ).A internetsB LANC intranetsD WAN23.The internet allows ( ) running on its end systems to exchange data with each other.A clients applicationsB server applicationsC P2P applicationsD distributed applications24.The Internet provides two services to its distributed applications: a connectionless unreliable service and () service.A flow controlB connection-oriented reliableC congestion controlD TCP25.It defines the format and the order of messages exchanged between two or more communicating entities, as well as the actions taken on thetransmission and/or receipt of a message or other event. The sentence describes ( ).A InternetB protocolC intranetD network26.In the following options, which does not define in protocol? ( )A the format of messages exchanged between two or morecommunicating entitiesB the order of messages exchanged between two or morecommunicating entitiesC the actions taken on the transmission of a message or other eventD the transmission signals are digital signals or analog signals 27.In the following options, which is defined in protocol? ( )A the actions taken on the transmission and/or receipt of a message orother eventB the objects exchanged between communicating entitiesC the content in the exchanged messagesD the location of the hosts28.In the following options, which does not belong to the network edge? ( )A end systemsB routersC clientsD servers29.In the following options, which belongs to the network core? ( )A end systemsB routersC clientsD servers30.In the following options, which is not the bundled with the Internet’s connection-oriented service? ( )A reliable data transferB guarantee of the transmission timeC flow controlD congestion-control31.An application can rely on the connection to deliver all of its data without error and in the proper order. The sentence describes ( ).A flow controlB congestion-controlC reliable data transferD connection-oriented service32.It makes sure that neither side of a connection overwhelms the other side by sending too many packets too fast. The sentence describes ( ).A flow controlB congestion-controlC connection-oriented serviceD reliable data transfer33.It helps prevent the Internet from entering a state of gridlock. When a packet switch becomes congested, its buffers can overflow and packet loss can occur. The sentence describes ( ).A flow controlB congestion-controlC connection-oriented serviceD reliable data transfer34.The Internet’s connection-oriented service has a name, it is ( ).A TCPB UDPC TCP/IPD IP35.In the following options, which service does not be provided to an application by TCP?( )A reliable transportB flow controlC video conferencingD congestion control36.The Internet’s connectionless service is called ( ).A TCPB UDPC TCP/IPD IP37.In the following options, which does not use TCP?( )A SMTPB internet telephoneC FTPD HTTP 38.In the following options, which does not use UDP?( )A Internet phoneB video conferencingC streaming multimediaD telnet39.There are two fundamental approaches to building a network core, ( ) and packet switching.A electrical current switchingB circuit switchingC data switchingD message switching40.In ( ) networks, the resources needed along a path to provide for communication between the end system are reserved for the duration of the communication session.A packet-switchedB data-switchedC circuit-switchedD message-switched41.In ( ) networks, the resources are not reserved; a session’s messages use the resources on demand, and as a consequence, may have to wait for access to communication link.A packet-switchedB data-switchedC circuit-switchedD message-switched42.In a circuit-switched network, if each link has n circuits, for each link used by the end-to-end connection, the connection gets ( ) of thelink’s bandwidth for the duration of the connection.A a fraction 1/nB allC 1/2D n times43.For ( ), the transmission rate of a circuit is equal to the frame rate multiplied by the number of bits in a slot.A CDMAB packet-switched networkC TDMD FDM44.( ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Queuing delayB Store-and-forward transmissionC Packet lossD Propagation45.The network that forwards packets according to host destination addresses is called ( ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram46.The network that forwards packets according to virtual-circuit numbers is called ( ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram47.In the following entries, which is not a kind of access network?( )A residential accessB company accessC wireless accessD local access48.Suppose there is exactly one packet switch between a sending host and a receiving host. The transmission rates between the sending host and the switch and between the switch and the receiving host are R1 and R2,respectively. Assuming that the switch uses store-and-forward packetswitching, what is the total end-to-end delay to send a packet of length L? (Ignore queuing delay, propagation delay, and processing delay.)( )A L/R1+L/R2B L/R1C L/R2D none of the above49.The time required to examine the packet’s header and determine where to direct the packet is part of the ( ).A queuing delayB processing delayC propagation delayD transmission delay50.The time required to propagate from the beginning of the link to the next router is ( ).A queuing delayB processing delayC propagation delayD transmission delay51.Consider sending a packet of 3000bits over a path of 5 links. Each link transmits at 1000bps. Queuing delays, propagation delay and processing delay are negligible. (6 points)(1).Suppose the network is a packet-switched virtual circuit network. VC setup time is 0.1 seconds. Suppose the sending layers add a total of 500 bits of header to each packet. How long does it take to send the file from source to destination?(2).Suppose the network is a packet-switched datagram network and a connectionless service is used. Now suppose each packet has 200 bits of header. How long does it take to send the file?(3).Suppose that the network is a circuit-switched network. Further suppose that the transmission rate of the circuit between source and destination is 200bps. Assuming 0.02s setup time and 200 bits of header appended to the packet, how long does it take to send the packet?Solution: (1). t=5*(3000+500)/1 000+0.1=17.6s(2). t=5*(3000+200)/1 000=16s(3). t=(3000+200)/200+0.02=16.02s 相对压力一般指表压,是测量系统相对于大气压的压力值。

计算机网络英文题库(附答案)chapter1(推荐文档)

计算机网络英文题库(附答案)chapter1(推荐文档)

Chapter 1 Computer Networks and the Internet1.The ( ) is a worldwide computer network, that is, a network that interconnects millions of computing devices throughout the world.ppt3A public InternetB IntranetC switch netD television net2.Which kind of media is not a guided media? ( )A twisted-pair copper wireB a coaxial cableC fiber opticsD digital satellite channel3.Which kind of media is a guided media? ( )A geostationary satelliteB low-altitude satelliteC fiber opticsD wireless LAN4.The units of data exchanged by a link-layer protocol are called ( ).A FramesB SegmentsC DatagramsD bit streams5.Which of the following option belongs to the circuit-switched networks? ( )A FDMB TDMC VC networksD both A and B6.( )makes sure that neither side of a connection overwhelms the other side by sending too many packets too fast.A Reliable data transferB Flow controlC Congestion controlD Handshaking procedure7.( ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Store-and-forward transmissionB FDMC End-to-end connectionD TDM8.Datagram networks and virtual-circuit networks differ in that ( ).A datagram networks are circuit-switched networks, andvirtual-circuit networks are packet-switched networks.B datagram networks are packet-switched networks, andvirtual-circuit networks are circuit-switched networks.C datagram networks use destination addresses and virtual-circuitnetworks use VC. numbers to forward packets toward theirdestination.D datagram networks use VC. numbers and virtual-circuit networksuse destination addresses to forward packets toward their destination. 9.In the following options, which one is not a guided media? ( )A twisted-pair wireB fiber opticsC coaxial cableD satellite10.Processing delay does not include the time to ( ).A examine the packet’s headerB wait to transmit the packet onto the linkC determine where to direct the packetD check bit-error in the packet11.In the following four descriptions, which one is correct? ( )A The traffic intensity must be greater than 1.B The fraction of lost packets increases as the traffic intensitydecreases.C If the traffic intensity is close to zero, the average queuing delaywill be close to zero.D If the traffic intensity is close to one, the average queuing delaywill be close to one.12.The Internet’s network layer is responsible for moving network-layer packets known as ( ) from one host to another.A frameB datagramC segmentD message13.The protocols of various layers are called ( ).A the protocol stackB TCP/IPC ISPD network protocol14.There are two classes of packet-switched networks: ( ) networks and virtual-circuit networks.A datagramB circuit-switchedC televisionD telephone15.Access networks can be loosely classified into three categories: residential access, company access and ( ) access.A cabledB wirelessC campusD city areaQuestion 16~17Suppose, a is the average rate at which packets arrive at the queue, R is the transmission rate, and all packets consist of L bits, then the traffic intensity is ( 16 ), and it should no greater than ( 17 ).16. A LR/aB La/RC Ra/LD LR/a17.A 2B 1C 0D -118.In the Internet, the equivalent concept to end systems is ( ).A hostsB serversC clientsD routers19.In the Internet, end systems are connected together by ( ).A copper wireB coaxial cableC communication linksD fiber optics20.End systems access to the Internet through its ( ).A modemsB protocolsC ISPD sockets21.End systems, packet switches, and other pieces of the Internet, run ( ) that control the sending and receiving of information within theInternet.A programsB processesC applicationsD protocols22.There are many private networks, such as many corporate and government networks, whose hosts cannot exchange messages withhosts outside of the private network. These private networks are often referred to as ( ).A internetsB LANC intranetsD WAN23.The internet allows ( ) running on its end systems to exchange data with each other.A clients applicationsB server applicationsC P2P applicationsD distributed applications24.The Internet provides two services to its distributed applications: a connectionless unreliable service and () service.A flow controlB connection-oriented reliableC congestion controlD TCP25.It defines the format and the order of messages exchanged between two or more communicating entities, as well as the actions taken on thetransmission and/or receipt of a message or other event. The sentence describes ( ).A InternetB protocolC intranetD network26.In the following options, which does not define in protocol? ( )A the format of messages exchanged between two or morecommunicating entitiesB the order of messages exchanged between two or morecommunicating entitiesC the actions taken on the transmission of a message or other eventD the transmission signals are digital signals or analog signals 27.In the following options, which is defined in protocol? ( )A the actions taken on the transmission and/or receipt of a message orother eventB the objects exchanged between communicating entitiesC the content in the exchanged messagesD the location of the hosts28.In the following options, which does not belong to the network edge? ( )A end systemsB routersC clientsD servers29.In the following options, which belongs to the network core? ( )A end systemsB routersC clientsD servers30.In the following options, which is not the bundled with the Internet’s connection-oriented service? ( )A reliable data transferB guarantee of the transmission timeC flow controlD congestion-control31.An application can rely on the connection to deliver all of its data without error and in the proper order. The sentence describes ( ).A flow controlB congestion-controlC reliable data transferD connection-oriented service32.It makes sure that neither side of a connection overwhelms the other side by sending too many packets too fast. The sentence describes ( ).A flow controlB congestion-controlC connection-oriented serviceD reliable data transfer33.It helps prevent the Internet from entering a state of gridlock. When a packet switch becomes congested, its buffers can overflow and packet loss can occur. The sentence describes ( ).A flow controlB congestion-controlC connection-oriented serviceD reliable data transfer34.The Internet’s connection-oriented service has a name, it is ( ).A TCPB UDPC TCP/IPD IP35.In the following options, which service does not be provided to an application by TCP?( )A reliable transportB flow controlC video conferencingD congestion control36.The Internet’s connectionless service is called ( ).A TCPB UDPC TCP/IPD IP37.In the following options, which does not use TCP?( )A SMTPB internet telephoneC FTPD HTTP38.In the following options, which does not use UDP?( )A Internet phoneB video conferencingC streaming multimediaD telnet39.There are two fundamental approaches to building a network core, ( ) and packet switching.A electrical current switchingB circuit switchingC data switchingD message switching 40.In ( ) networks, the resources needed along a path to provide for communication between the end system are reserved for the duration of the communication session.A packet-switchedB data-switchedC circuit-switchedD message-switched41.In ( ) networks, the resources are not reserved; a session’s messages use the resources on demand, and as a consequence, may have to wait for access to communication link.A packet-switchedB data-switchedC circuit-switchedD message-switched42.In a circuit-switched network, if each link has n circuits, for each link used by the end-to-end connection, the connection gets ( ) of thelink’s bandwidth for the duration of the connection.A a fraction 1/nB allC 1/2D n times43.For ( ), the transmission rate of a circuit is equal to the frame rate multiplied by the number of bits in a slot.A CDMAB packet-switched networkC TDMD FDM44.( ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Queuing delayB Store-and-forward transmissionC Packet lossD Propagation45.The network that forwards packets according to host destination addresses is called ( ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram46.The network that forwards packets according to virtual-circuit numbers is called ( ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram47.In the following entries, which is not a kind of access network?( )A residential accessB company accessC wireless accessD local access48.Suppose there is exactly one packet switch between a sending host and a receiving host. The transmission rates between the sending host and the switch and between the switch and the receiving host are R1 and R2,respectively. Assuming that the switch uses store-and-forward packetswitching, what is the total end-to-end delay to send a packet of length L? (Ignore queuing delay, propagation delay, and processing delay.)( )A L/R1+L/R2B L/R1C L/R2D none of the above49.The time required to examine the packet’s header and determine where to direct the packet is part of the ( ).A queuing delayB processing delayC propagation delayD transmission delay50.The time required to propagate from the beginning of the link to the next router is ( ).A queuing delayB processing delayC propagation delayD transmission delay51.Consider sending a packet of 3000bits over a path of 5 links. Each link transmits at 1000bps. Queuing delays, propagation delay and processing delay are negligible. (6 points)(1).Suppose the network is a packet-switched virtual circuit network. VC setup time is 0.1 seconds. Suppose the sending layers add a total of 500 bits of header to each packet. How long does it take to send the file from source to destination?(2).Suppose the network is a packet-switched datagram network and a connectionless service is used. Now suppose each packet has 200 bits of header. How long does it take to send the file?(3).Suppose that the network is a circuit-switched network. Further suppose that the transmission rate of the circuit between source and destination is 200bps. Assuming 0.02s setup time and 200 bits of header appended to the packet, how long does it take to send the packet?Solution: (1). t=5*(3000+500)/1 000+0.1=17.6s(2). t=5*(3000+200)/1 000=16s(3). t=(3000+200)/20 0+0.02=16.02s。

计算机网络英文题库附答案chapter定稿版

计算机网络英文题库附答案chapter定稿版

计算机网络英文题库附答案c h a p t e r精编W O R D版IBM system office room 【A0816H-A0912AAAHH-GX8Q8-GNTHHJ8】Chapter 1 Computer Networks and the Internet 1.The ( ) is a worldwide computer network, that is, a network that interconnects millions of computing devices throughout the world.ppt3A public InternetB IntranetC switch netD television net2.Which kind of media is not a guided media ( )A twisted-pair copper wireB a coaxial cableC fiber opticsD digital satellite channel3.Which kind of media is a guided media ( )A geostationary satelliteB low-altitude satelliteC fiber opticsD wireless LAN4.The units of data exchanged by a link-layer protocol are called ( ).A FramesB SegmentsC DatagramsD bit streams5.Which of the following option belongs to the circuit-switched networks ( )A FDMB TDMC VC networksD both A and B6.( )makes sure that neither side of aconnection overwhelms the other side bysending too many packets too fast.A Reliable data transferB Flow controlC Congestion controlD Handshaking procedure7.( ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Store-and-forward transmissionB FDMC End-to-end connectionD TDM8.Datagram networks and virtual-circuit networks differ in that ( ).A datagram networks are circuit-switchednetworks, and virtual-circuit networks arepacket-switched networks.B datagram networks are packet-switchednetworks, and virtual-circuit networks arecircuit-switched networks.C datagram networks use destinationaddresses and virtual-circuit networks useVC. numbers to forward packets towardtheir destination.D datagram networks use VC. numbersand virtual-circuit networks use destinationaddresses to forward packets toward theirdestination.9.In the following options, which one is not a guided media ( )A twisted-pair wireB fiber opticsC coaxial cableD satellite10.Processing delay does not include the time to ( ).A examine the packet’s headerB wait to transmit the packet onto the linkC determine where to direct the packetD check bit-error in the packet11.In the following four descriptions, which one is correct ( )A The traffic intensity must be greaterthan 1.B The fraction of lost packets increases asthe traffic intensity decreases.C If the traffic intensity is close to zero,the average queuing delay will be close tozero.D If the traffic intensity is close to one, theaverage queuing delay will be close to one.12.The Internet’s network layer isresponsible for moving network-layerpackets known as ( ) from one host toanother.A frameB datagramC segmentD message13.The protocols of various layers are called ( ).A the protocol stackB TCP/IPC ISPD network protocol14.There are two classes of packet-switched networks: ( ) networks and virtual-circuitnetworks.A datagramB circuit-switchedC televisionD telephone15.Access networks can be loosely classified into three categories: residential access,company access and ( ) access.A cabledB wirelessC campusD city areaQuestion 16~17Suppose, a is the average rate at which packets arrive at the queue, R is the transmission rate, and all packets consist of L bits, then the traffic intensity is ( 16 ), and it should no greater than ( 17 ).16.A LR/aB La/RC Ra/LD LR/a 17.A 2B 1C 0D -118.In the Internet, the equivalent concept to end systems is ( ).A hostsB serversC clientsD routers19.In the Internet, end systems are connected together by ( ).A copper wireB coaxial cableC communication linksD fiber optics20.End systems access to the Internet through its ( ).A modemsB protocolsC ISPD sockets21.End systems, packet switches, and other pieces of the Internet, run ( ) that controlthe sending and receiving of informationwithin the Internet.A programsB processesC applicationsD protocols22.There are many private networks, such as many corporate and government networks,whose hosts cannot exchange messageswith hosts outside of the private network.These private networks are often referredto as ( ).A internetsB LANC intranetsD WAN23.The internet allows ( ) running on its end systems to exchange data with each other.A clients applicationsB server applicationsC P2P applicationsD distributed applications24.The Internet provides two services to its distributed applications: a connectionlessunreliable service and () service.A flow controlB connection-oriented reliableC congestion controlD TCP25.It defines the format and the order of messages exchanged between two or morecommunicating entities, as well as theactions taken on the transmission and/orreceipt of a message or other event. Thesentence describes ( ).A InternetB protocolC intranetD network26.In the following options, which does not define in protocol ( )A the format of messages exchangedbetween two or more communicatingentitiesB the order of messages exchangedbetween two or more communicatingentitiesC the actions taken on the transmission ofa message or other eventD the transmission signals are digitalsignals or analog signals27.In the following options, which is defined in protocol ( )A the actions taken on the transmissionand/or receipt of a message or othereventB the objects exchanged between communicating entitiesC the content in the exchanged messagesD the location of the hosts28.In the following options, which does not belong to the network edge ( )A end systemsB routersC clientsD servers29.In the following options, which belongs to the network core ( )A end systemsB routersC clientsD servers30.In the following options, which is not the bundled with the Internet’s connection-oriented service( )A reliable data transferB guarantee of the transmission timeC flow controlD congestion-control31.An application can rely on the connection to deliver all of its data without error andin the proper order. The sentencedescribes ( ).A flow controlB congestion-controlC reliable data transferD connection-oriented service32.It makes sure that neither side of aconnection overwhelms the other side bysending too many packets too fast. Thesentence describes ( ).A flow controlB congestion-controlC connection-oriented serviceD reliable data transfer33.It helps prevent the Internet from enteringa state of gridlock. When a packet switchbecomes congested, its buffers canoverflow and packet loss can occur. Thesentence describes ( ).A flow controlB congestion-controlC connection-oriented serviceD reliable data transfer34.The Internet’s connection-oriented service has a name, it is ( ).A TCPB UDPC TCP/IPD IP 35.In the following options, which service does not be provided to an application by TCP( )A reliable transportB flow controlC video conferencingD congestion control36.The Internet’s connectionless service is called ( ).A TCPB UDPC TCP/IPD IP37.In the following options, which does not use TCP()A SMTPB internet telephoneC FTPD HTTP38.In the following options, which does not use UDP( )A Internet phoneB video conferencingC streaming multimediaD telnet39.There are two fundamental approaches to building a network core, ( ) and packetswitching.A electrical current switchingB circuit switchingC data switchingD message switching40.In ( ) networks, the resources needed along a path to provide forcommunication between the end systemare reserved for the duration of thecommunication session.A packet-switchedB data-switchedC circuit-switchedD message-switched41.In ( ) networks, the resources are not reserved; a session’s messages use theresources on demand, and as aconsequence, may have to wait for accessto communication link.A packet-switchedB data-switchedC circuit-switchedD message-switched42.In a circuit-switched network, if each link has n circuits, for each link used by theend-to-end connection, the connectiongets ( ) of the link’s bandwidth for theduration of the connection.A a fraction 1/nB allC 1/2D n times43.For ( ), the transmission rate of a circuit is equal to the frame rate multiplied by thenumber of bits in a slot.A CDMAB packet-switched networkC TDMD FDM 44.( ) means that the switch must receive the entire packet before it can begin totransmit the first bit of the packet onto theoutbound link.A Queuing delayB Store-and-forward transmissionC Packet lossD Propagation45.The network that forwards packetsaccording to host destination addresses iscalled ( ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram46.The network that forwards packetsaccording to virtual-circuit numbers iscalled ( ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram47.In the following entries, which is not a kind of access network()A residential accessB company accessC wireless accessD local access48.Suppose there is exactly one packet switch between a sending host and a receivinghost. The transmission rates between thesending host and the switch and betweenthe switch and the receiving host are R1and R2, respectively. Assuming that theswitch uses store-and-forward packetswitching, what is the total end-to-enddelay to send a packet of length L (Ignorequeuing delay, propagation delay, andprocessing delay.) ( )A L/R1+L/R2B L/R1C L/R2D none of the above49.The time required to examine thepacket’s header and determine where todirect the packet is part of the ( ).A queuing delayB processing delayC propagation delayD transmission delay50.The time required to propagate from the beginning of the link to the next router is( ).A queuing delayB processing delayC propagation delayD transmission delay51.Consider sending a packet of 3000bits over a path of 5 links. Each link transmits at 1000bps. Queuing delays, propagation delay and processing delay are negligible. (6 points) (1).Suppose the network is a packet-switched virtual circuit network. VC setup time is 0.1 seconds. Suppose the sending layers add a total of 500 bits of header to each packet. How long does it take to send the file from source to destination?(2).Suppose the network is a packet-switched datagram network and a connectionless serviceis used. Now suppose each packet has 200 bitsof header. How long does it take to send the file?(3).Suppose that the network is a circuit-switched network. Further suppose that the transmission rate of the circuit between sourceand destination is 200bps. Assuming 0.02s setuptime and 200 bits of header appended to the packet, how long does it take to send the packet?So lution:(1).t=5*(3000+500)/1000+0.1=17.6s( 2).t=5*(3000+200)/1000=16s( 3).t=(3000+200)/200+0.02=16.02s。

计算机网络英文题库附答案chapter1

计算机网络英文题库附答案chapter1

networks use VC. numbers to forward packets toward their Chapter 1 Computer Networks and the Internet destination.thatis, a network is a worldwide computer network, that 1.The ( )Ddatagram networks use VC. numbers and virtual-circuit of computing devices throughout the world. interconnects millions networks use destination addresses to forward packets toward their ppt3destination. A public InternetB Intranet9.In the following options, which one is not a guided media ( )A twisted-pair wire C switch netfiber opticsD B television netcoaxial cable C 2.Which kind of media is not a guided media ( ) A D satellite twisted-pair copper wirea coaxial cableB 10.Processing delay does not include the time to ( ).C fiber optics A examine the packet's headerB wait to transmit the packet onto the linkdigital satellite channel DC determine where to direct the packet)3.Which kind of media is a guided media (D check bit-error in the packet A geostationary satellite11.In the following four descriptions, which one is correct ( )low-altitude satelliteB A The traffic intensity must be greater than 1. C fiber optics B The fraction of lost packets increases as the traffic intensity Dwireless LANdecreases.).The units of data exchanged by a link-layer protocol are called ( 4.C If the traffic intensity is close to zero, the average queuing delay A Frames will be close to zero.B SegmentsDIf the traffic intensity is close to one, the average queuing delayC Datagrams will be close to one.D bit streams12.The Internet's network layer is responsible for moving network-layerWhich of the following option belongs to the circuit-switched networks5.packets known as ( ) from one host to another.)( A frameA FDMB datagram B TDMC segmentVC networks C D message both A and BD13.The protocols of various layers are called ( ).)makes sure that neither side of a connection overwhelms the other( 6.A the protocol stackside by sending too many packets too fast.B TCP/IP Reliable data transfer A C ISPFlow controlB Dnetwork protocol C Congestion control 14.There are two classes of packet-switched networks: ( ) networks andDHandshaking procedurevirtual-circuit networks.) means that the switch must receive the entire packet before it can.7( A datagram begin to transmit the first bit of the packet onto the outbound link.B circuit-switched A Store-and-forward transmissionC television B FDM End-to-end connection C DtelephoneD TDM15.Access networks can be loosely classified into three categories:residential access, company access and ( ) access.8Datagram networks and virtual-circuit networks differ in that ( .).datagram networks are circuit-switched networks, and A A cabledvirtual-circuit networks are packet-switched networks.B wirelessdatagram networks are packet-switched networks, and B C campus virtual-circuit networks are circuit-switched networks.city areaDdatagram networks use destination addresses and virtual-circuitCC P2P applications 17Question 16~distributed applicationsDRSuppose, a is the average rate at which packets arrive at the queue, 24.The Internet provides two services to its distributed applications: atraffic then the is the transmission rate, and all packets consist of L bits, connectionless unreliable service and () service. intensity is ( 16 ), and it should no greater than ( 17 ).A flow controlLR16.A/a connection-oriented reliableBB La/R congestion control CTCPD/C RaL25.It defines the format and the order of messages exchanged betweenLRD /atwo or more communicating entities, as well as the actions taken on .17A 2the transmission and/or receipt of a message or other event. TheB1sentence describes ( ).C 0 A InternetD -1B protocol).18.In the Internet, the equivalent concept to end systems is ( C intranethosts A D networkB servers26.In the following options, which does not define in protocol ( )C clients A the format of messages exchanged between two or moreroutersD communicating entities). 19.In the Internet, end systems are connected together by ( B the order of messages exchanged between two or moreA copper wire communicating entitiescoaxial cableB C the actions taken on the transmission of a message or otherC communication links eventfiber opticsD Dthe transmission signals are digital signals or analog signals).End systems access to the Internet through its ( 20.27.In the following options, which is defined in protocol ( )A modems A the actions taken on the transmission and/or receipt of a message protocolsB or other eventISP C B the objects exchanged between communicating entitiesDsockets C the content in the exchanged messages).End systems, packet switches, and other pieces of the Internet, run ( 21 D the location of the hoststhat control the sending and receiving of information within the 28.In the following options, which does not belong to the network edgeInternet.( )A programs A end systemsB processes B routersapplications C C clientsDprotocols D serversThere are many private networks, such as many corporate and22.29.In the following options, which belongs to the network core ( )government networks, whose hosts cannot exchange messages with A end systemshosts outside of the private network. These private networks are often B routers). referred to as ( C clientsinternets A DserversB LAN30.In the following options, which is not the bundled with the Internet'sC intranets connection-oriented service ( )DWANA reliable data transfer) running on its end systems to exchange data.23The internet allows ( B guarantee of the transmission timewith each other.Cflow controlclients applications A congestion-controlDserver applicationsBA electrical current switching An application can rely on the connection to deliver all of its data.31circuit switching ).B without error and in the proper order. The sentence describes (data switching A flow control Cmessage switchingB Dcongestion-controlreliable data transfer C 40.In ( ) networks, the resources needed along a path to provide for communication between the end system are reserved for the duration connection-oriented serviceDof the communication session.32.It makes sure that neither side of a connection overwhelms the otherside by sending too many packets too fast. The sentence describes A packet-switchedB data-switched).(C circuit-switched A flow controlDB congestion-control message-switchedC connection-oriented service 41.In ( ) networks, the resources are not reserved; a session's messagesuse the resources on demand, and as a consequence, may have to wait reliable data transfer Dfor access to communication link.It helps prevent the Internet from entering a state of gridlock. When a33.A packet-switched packet switch becomes congested, its buffers can overflow and packetB data-switched loss can occur. The sentence describes ( ).C circuit-switched A flow controlDmessage-switched B congestion-controlC connection-oriented service 42.In a circuit-switched network, if each link has n circuits, for each linkused by the end-to-end connection, the connection gets ( ) of the D reliable data transferlink's bandwidth for the duration of the connection.34.The Internet's connection-oriented service has a name, it is ( ).A a fraction 1/n A TCPB all B UDPC 1/2 C TCP/IPDn times DIP43an to .For ( ), the transmission rate of a circuit is equal to the frame ratenot options, the .35In following which service does be providedmultiplied by the number of bits in a slot.application by TCP( )A CDMA reliable transport AB packet-switched network flow controlBC TDM C video conferencingDFDM D congestion control44)..( ) means that the switch must receive the entire packet before it can.36The Internet's connectionless service is called (begin to transmit the first bit of the packet onto the outbound link. TCP AA Queuing delay UDPBB C TCP/IP Store-and-forward transmissionC Packet loss IPDDPropagation)In the following options, which does not use TCP( 37.SMTP A 45.The network that forwards packets according to host destinationaddresses is called ( internet telephone ) network.BA C circuit-switched FTPB packet-switched HTTPDC virtual-circuit In the following options, which does not use UDP( .38 )DA Internet phone datagramB video conferencing46.The network that forwards packets according to virtual-circuit numbersis called ( ) network.streaming multimedia CA Dcircuit-switched telnetB packet-switched)39 There are two fundamental approaches to building a network core, ( .virtual-circuit Cand packet switching.D datagram=47.In the following entries, which is not a kind of access network( )A residential accessB company access wireless access Clocal accessD48.Suppose there is exactly one packet switch between a sending host anda receiving host. The transmission rates between the sending host andthe switch and between the switch and the receiving host are R and 1R, respectively. Assuming that the switch uses store-and-forward 2packet switching, what is the total end-to-end delay to send a packetof length L (Ignore queuing delay, propagation delay, and processingdelay.) ( )A L/R+L/R 21/B RL1L/C R 2none of the aboveD 49.The time required to examine the packet's header and determine whereto direct the packet is part of the ( ).A queuing delayB processing delayC propagation delayDtransmission delay50.The time required to propagate from the beginning of the link to thenext router is ( ).A queuing delayB processing delayC propagation delayDtransmission delay51.Consider sending a packet of 3000bits over a path of 5 links. Each linktransmits at 1000bps. Queuing delays, propagation delay and processingdelay are negligible. (6 points)(1).Suppose the network is a packet-switched virtual circuit network. VCsetup time is seconds. Suppose the sending layers add a total of 500 bitsof header to each packet. How long does it take to send the file from sourceto destination(2).Suppose the network is a packet-switched datagram network and aconnectionless service is used. Now suppose each packet has 200 bits ofheader. How long does it take to send the file(3).Suppose that the network is a circuit-switched network. Further supposethat the transmission rate of the circuit between source and destination is200bps. Assuming setup time and 200 bits of header appended to thepacket, how long does it take to send the packetSolution:(1).t=5*(3000+500)/1000+=(2).t=5*(3000+200)/1000=16s200+(3).t=(3000+200)/。

网络英语试题及答案

网络英语试题及答案

网络英语试题及答案一、选择题(每题1分,共10分)1. What does the abbreviation "WWW" stand for?A. World Wild WebB. World Wide WebC. World War WebD. World Wonder Web2. Which of the following is the most common way to access the internet?A. RadioB. TelevisionC. Telephone lineD. Satellite3. The term "URL" refers to:A. Uniform Resource LocatorB. Unique Resource LocatorC. User Resource LocatorD. Universal Resource Locator4. What is the primary function of a search engine?A. To play musicB. To send emailsC. To find information on the internetD. To make online purchases5. Which of the following is not a social media platform?A. FacebookB. TwitterC. LinkedInD. Photoshop6. What is the full form of "HTTP"?A. HyperText Transfer ProtocolB. HyperText Transport ProtocolC. HighText Transfer ProtocolD. HighText Transport Protocol7. What is the purpose of cookies on the internet?A. To store user preferences and track browsing historyB. To send messages to friendsC. To play videosD. To make online reservations8. Which of the following is a type of malware?A. VirusB. EmailC. FirewallD. Antivirus9. What does "VPN" stand for?A. Virtual Private NetworkB. Very Personal NetworkC. Video Personal NetworkD. Virtual Programming Network10. Which protocol is used for sending emails?A. FTPB. SMTPC. TCPD. UDP二、填空题(每空1分,共10分)11. The internet is a global system of interconnected computer networks that use the __________ protocol suite to link devices worldwide.12. When you want to download a file from the internet, you might use a __________ client.13. A __________ is a program that displays and runs documents written in HTML.14. The process of making a website accessible to users with disabilities is known as __________.15. The term "cyberbullying" refers to bullying or harassment that takes place __________.三、简答题(每题5分,共20分)16. Explain the difference between an intranet and an extranet.17. What are the benefits of using a cloud service for data storage?18. Describe the steps to create a new email account.19. What are some common security measures to protect personal information online?四、论述题(每题15分,共30分)20. Discuss the impact of social media on modern communication.21. Analyze the role of the internet in e-commerce and its implications for traditional businesses.五、翻译题(每题5分,共10分)22. 将以下句子翻译成英文:“网络改变了我们的生活和工作方式。

(完整版)计算机网络英文题库(附答案)chapter5

(完整版)计算机网络英文题库(附答案)chapter5

(完整版)计算机⽹络英⽂题库(附答案)chapter5 Chapter 5 The Link Layer and Local Area Network1.A ( ) protocol is used to move a datagram over an individual link.A application-layerB transport-layerC network-layerD link-layer2.The units of data exchanged by a link-layer protocol are called ( ).A datagramsB framesC segmentsD messages3.Which of the following protocols is not a link-layer protocol? ( )A EthernetB PPPC HDLCD IP4.In the following four descriptions, which one is not correct? ( )A link-layer protocol has the node-to-node job of moving network-layer datagrams over a single link in the path.B The services provided by the link-layer protocols may be different.C A datagram must be handled by the same link-layer protocols on the different links in the path.D The actions taken by a link-layer protocol when sending and receiving frames include error detection, flow control and random access.5.Which of the following services can not offered by a link-layer protocol? ( )A congestion controlB Link AccessC Error controlD Framing6.( ) protocol serves to coordinate the frame transmissions of the many nodes when multiple nodes share a single broadcast link.A ARPB MACC ICMPD DNS7.In the following four descriptions about the adapter, which one is not correct? ( )A The adapter is also called as NIC.B The adapter is a semi-autonomous unit.C The main components of an adapter are bus interface and the link interface.D The adapter can provide all the link-layer services.8.Consider CRC error checking approach, the four bit generator G is 1011, and suppose that the data D is 10101010, then the value of R is( ).A 010B 100C 011D 1109.In the following four descriptions about random access protocol, which one is not correct? ( )A I n slotted ALOHA, nodes can transmit at random time.B I n pure ALOHA, if a frame experiences a collision, the node will immediately retransmit it with probability p.C T he maximum efficiency of a slotted ALOHA is higher than a pure ALOHA.D I n CSMA/CD, one node listens to the channel before transmitting.10.In the following descriptions about MAC address, which one is not correct? ( )A T he MAC address is the address of one node’s adapter.B N o two adapters have the same MAC address.C T he MAC address doesn’t change no matter where the adapter goes.D M AC address has a hierarchical structure.11.The ARP protocol can translate ( ) into ( ). ( )A h ost name, IP addressB h ost name, MAC addressC I P address, MAC addressD broadcast address, IP address12.The value of Preamble field in Ethernet frame structure is ( )A 10101010 10101010……10101010 11111111B 10101011 10101011……10101011 10101011C 10101010 10101010……10101010 10101011D 10101010 10101010……10101010 1010101013.There are four steps in DHCP, the DHCP server can complete ( ).A DHCP server discoveryB DHCP server offersC DHCP requestD DHCP response14.In CSMA/CD, the adapter waits some time and then returns to sensing the channel. In the following four times, which one is impossible? ( )A 0 bit timesB 512 bit timesC 1024 bit timesD 1028 bit times15.The most common Ethernet technologies are 10BaseT and 100BaseT. “10” and “100” indicate( ).A the maximum length between two adaptersB the minimum length between two adaptersC the transmission rate of the channelD the transmission rate of the node16.The principal components of PPP include but not( ).A framingB physical-control protocolC link-layer protocolD network-layer protocol17.In the following four options, which service can not be provided by switch? ( )A filteringB self-learningC forwardingD optimal routing18.In the following four services, which one was be required in PPP? ( )A packet framingB error detectionC error correctionD multiple types of link19.The ability to determine the interfaces to which a frame should be directed, and then directing the frame to those interfaces is( ).A filteringB forwardingC self-learningD optimal routing20.In ( ) transmission(s), the nodes at both ends of a link may transmit packets at the same time.A full-duplexB half-duplexC single-duplexD both full-duplex and half-duplex21.Consider the data D is 01110010001, if use even parity checking approach, the parity bit is( ① ), if use odd parity checking approach, the parity bit is( ② ). ( )A ①0 ②1B ①0 ②0C ①1 ②1D ①1 ②022.In the following four descriptions about parity checks, which one is correct? ( )A Single-bit parity can detect all errors.B Single-bit parity can correct one errors.C Two-dimensional parity not only can detect a single bit error, but also can correct that error.D Two-dimensional parity not only can detect any combination of two errors, but also can correct them.23.MAC address is ( ) bits long.A 32B 48C 128D 6424.Wireless LAN using protocol ( ).A IEEE 802.3B IEEE 802.4C IEEE 802.5D IEEE 802.1125.The following protocols are belonging to multiple access protocols except for ( ).A channel partitioning protocolsB routing protocolsC random access protocolsD taking-turns protocols26.Which of the following is not belonging to channel partitioning protocols? ( )A CSMAB FDMC CDMAD TDM27.In the following four descriptions about CSMA/CD, which one is not correct? ( )A A node listens to the channel before transmitting.B If someone else begins talking at the same time, stop talking.C A transmitting node listens to the channel while it is transmitting.D With CSMA/CD, the collisions can be avoided completely.28.( ) provides a mechanism for nodes to translate IP addresses to link-layer address.A IPB ARPC RARPD DNS29.A MAC address is a ( )address.A physical-layerB application-layerC link-layerD network-layer30.Which of the following is correct? ( )A No two adapters have the same MAC address.B MAC broadcast address is FF-FF-FF-FF-FF-FF.C A portable computer with an Ethernet card always has the same MAC address, no matter where the computer goes.D All of the above31.In the following four descriptions, which one is not correct? ( )A ARP resolves an IP address to a MAC address.B DNS resolves hostnames to IP addresses.C DNS resolves hostnames for hosts anywhere in the Internet.D ARP resolves IP addresses for nodes anywhere in the Internet.32.In the LAN, ( )protocol dynamically assign IP addresses to hosts.A DNSB ARPC DHCPD IP33.DHCP protocol is a four-step process: ①DHCP request. ②DHCP ACK. ③DHCP server discovery. ④DHCP server offer(s). The correct sequence is ( )A ①②③④B ③②①④C ③④①②D ①④③②34.In the Ethernet frame structure, the CRC field is ( )bytes.D 3235.In the Ethernet frame structure, the Data field carries the ( ).A IP datagramB segmentC frameD message36.In the following four descriptions, which one is not correct? ( )A Ethernet uses baseband transmission.B All of the Ethernet technologies provide connection-oriented reliable service to the network layer.C The Ethernet 10Base2 technology uses a thin coaxial cable for the bus.D The Ethernet 10BaseT technology uses a star topology.37.Ethernet’s multiple access protocol is ( ).A CDMAB CSMA/CDC slotted ALOHAD token-passing protocol38.In the following four descriptions about CSMA/CD, which one is not correct? ( )A An adapter may begin to transmit at any time.B An adapter never transmits a frame when it senses that some other adapter is transmitting.C A transmitting adapter aborts its transmission as soon as it detects that another adapter is also transmitting.D An adapter retransmits when it detects a collision.39.Which of the following descriptions about CSMA/CD is correct? ( )A No slots are used.B It uses carrier sensing.C It uses collision detection.D All of the above.40.The Ethernet 10BaseT technology uses( )as its physical media.A fiber opticsB twisted-pair copper wireC coaxial cableD satellite radio channel41.For 10BaseT, the maximum length of the connection between an adapter and the hub is ( )meters.D 1042.A ( )is a physical-layer device that acts on individual bits rather than on frames.A switchB hubC routerD gateway43.A hub is a ( )device that acts on individual bits rather than on frames.A physical-layerB link-layerC network-layerD ransport-layer44.A switch is a( )device that acts on frame.A physical-layerB link-layerC network-layerD transport-layer45.In the following four descriptions, which one is not correct? ( )A Switches can interconnect different LAN technologies.B Hubs can interconnect different LAN technologies.C There is no limit to how large a LAN can be when switches are used to interconnect LAN segments.D There is restriction on the maximum allowable number of nodes in a collision domain when hubs are used to interconnect LAN segments.46.The ability to determine whether a frame should be forwarded to some interface or should just be dropped is ( ).A f ilteringB f orwardingC s elf-learningD o ptimal routing47.Which of the following devices is not a plug and play device? ( )A hubB routerC switchD repeater48.Which of the following devices is not cut-through device? ( )D repeater49.In the following four descriptions, which one is not correct? ( )A Switches do not offer any protection against broadcast storms.B Routers provide firewall protection against layer-2 broadcast storms.C Both switches and routers are plug and play devices.D A router is a layer-3 packet switch, a switch is a layer-2 packet switch. 50.Which device has the same collision domain? ( )A HubB SwitchC RouterD Bridge51.IEEE802.2 protocol belong to ( )layerA networkB MACC LLCD physical52.IEEE802.11 protocol defines ( )rules.A Ethernet BusB wireless WANC wireless LAND Token Bus53.In data link-layer, which protocol is used to share bandwidth? ( )A SMTPB ICMPC ARPD CSMA/CD54.When two or more nodes on the LAN segments transmit at the same time, there will be a collision and all of the transmitting nodes well enter exponential back-off, that is all of the LAN segments belong to the same( ).A collision domainB switchC bridgeD hub55.( )allows different nodes to transmit simultaneously and yet have their respective receivers correctly receive a sender’s encoded data bits.C CSMA/CDD CSMA/CA56.Because there are both network-layer addresses (for example, Internet IP addresses) and link-layer addresses (that is, LAN addresses), there is a need totranslate between them. For the Internet, this is the job of ( ).A RIPB OSPFC ARPD IP57.PPP defines a special control escape byte, ( ). If the flag sequence, 01111110 appears anywhere in the frame, except in the flag field, PPP precedes that instance of the flag pattern with the control escape byte.A 01111110B 01111101C 10011001D 1011111058.The device ( ) can isolate collision domains for each of the LAN segment.A modemB switchC hubD NIC59.In the following four descriptions about PPP, which one is not correct? ( )A PPP is required to detect and correct errors.B PPP is not required to deliver frames to the link receiver in the same order in which they were sent by the link sender.C PPP need only operate over links that have a single sender and a single receiver.D PPP is not required to provide flow control.60.In the PPP data frame, the( ) field tells the PPP receivers the upper-layer protocol to which the received encapsulated data belongs.A flagB controlC protocolD checksum61.PPP’s link-control protocols (LCP) accomplish ( ).A initializing the PPP linkB maintaining the PPP linkC taking down the PPP linkD all of the above62.The PPP link always begins in the ( ) state and ends in the ( ) state. ( )A open, terminatingB open, deadC dead, deadD dead, terminating63.For( ) links that have a single sender at one end of the link and a single receiver at the other end of the link.A point-to-pointB broadcastC multicastD all of the above64.With ( )transmission, the nodes at both ends of a link may transmit packets at the same time.A half-duplexB full-duplexC simplex(单⼯)D synchronous65.With ( ) transmission, a node can not both transmit and receive at the same time.A half-duplexB full-duplexC simplex(单⼯)D synchronous66.Which of the following functions can’t be implemented in the NIC? ( )A encapsulation and decapsulationB error detectionC multiple access protocolD routing67.Which of the following four descriptions is wrong? ( )A The bus interface of an adapter is responsible for communication with the adapter’s parent node.B The link interface of an adapter is responsible for implementing the link-layer protocol.C The bus interface may provide error detection, random access functions.D The main components of an adapter are the bus interface and the link interface. 68.For odd parity schemes, which of the following is correct? ( )A 011010001B 111000110C 110101110D 00011011069.( )divides time into time frames and further divides each time frame into N time slots.A FDMB TMDC CDMAD CSMA70.With CDMA, each node is assigned a different ( )A codeB time slotC frequencyD link71.Which of the following four descriptions about random access protocol is not correct? ( )A A transmission node transmits at the full rate of the channelB When a collision happens, each node involved in the collision retransmits at once.C Both slotted ALOHA and CSMA/CD are random access protocols.D With random access protocol, there may be empty slots.72.PPP defines a special control escape byte 01111101. If the data is b1b201111110b3b4b5, the value is( )after byte stuffing.A b1b20111110101111110b3b4b5B b1b20111111001111101b3b4b5C b5b4b30111111001111101b2b1D b5b4b30111110101111110b2b173.MAC address is in ( ) of the computer.A RAMB NICC hard diskD cache74.Which of the following is wrong? ( )A ARP table is configured by a system administratorB ARP table is built automaticallyC ARP table is dynamicD ARP table maps IP addresses to MAC addresses75.NIC works in ( )layer.A physicalB linkC networkD transport76.In LAN, if UTP is used, the common connector is( ).A AUIB BNCC RJ-45D NNI77.The modem’s function(s) is(are) ( ).A translates digital signal into analog signalB translates analog signal into digital signalC both translates analog signal into digital signal and translates digital signal into analog signalD translates one kind of digital signal into another digital signal78.( )defines Token-Ring protocol.A IEEE 802.3B IEEE 802.4C IEEE 802.5D IEEE 802.279.( )defines Token-Bus protocol.A IEEE 802.3B IEEE 802.4C IEEE 802.5D IEEE 802.280.( ) defines CSMA/CD protocol.A IEEE 802.3B IEEE 802.4C IEEE 802.5D IEEE 802.281.The computer network that concentrated in a geographical area, such as in a building or on a university campus, is ( )A a LANB a MANC a WAND the Internet82.The MAC address is ( ) bits long.A 32B 48C 128D 25683.Which of the following four descriptions about MAC addresses is wrong? ( )A a MAC address is burned into the adapter’s ROMB No two adapters have the same addressC An adapter’s MAC address is dynamicD A MAC address is a link-layer address84.Which of the following four descriptions about DHCP is correct? ( )A DHCP is C/S architectureB DHCP uses TCP as its underlying transport protocolC The IP address offered by a DHCP server is valid foreverD The DHCP server will offer the same IP address to a host when the host requests an IP address85.The ( )field permits Ethernet to multiplex network-layer protocols.A preambleB typeC CRCD destination MAC address86.For 10BaseT, the maximum length of the connection between an adapter and the hub is ( ) meters.A 50B 100C 200D 50087.An entry in the switch table contains the following information excepts for ( )A the MAC address of a nodeB the switch interface that leads towards the nodeC the time at which the entry for the node was placed in the tableD the IP address of a node88.Consider the 4-bit generator , G is 1001, and suppose that D has the value 101110000. What is the value of R?89.Consider the following graph of the network. Suppose Host A will send a datagram to Host B, Host A run OICQ on port 4000, Host B run OICQ on port 8000. All of ARP tables are up to date. Enumerate all the steps when message “Hello” is sent from host A to host B.。

(完整版)计算机网络英文题库(附答案)chapter3

(完整版)计算机网络英文题库(附答案)chapter3

Chapter 3 Transport Layer1. A transport-layer protocol provides for logical communication between ____.A Application processesB HostsC RoutersD End systems2. Transport-layer protocols run in ____.A ServersB ClientsC RoutersD End systems3. In transport layer, the send side breaks application messages into ____, passes to network layer.A FramesB SegmentsC Data-gramsD bit streams4. Services provided by transport layer include ____.A HTTP and FTPB TCP and IPC TCP and UDPD SMTP5. Which of the following services is not provided by TCP?A Delay guarantees and bandwidth guaranteesB Reliable data transfers and flow controlsC Congestion controlsD In-order data transfers6. These two minimal transport-layer services----____ and ____----are the only two services that UDP provides!A process-to-process data delivery, error checkingB congestion control, reliable data transferC flow control, congestion controlD In-order data transfer, error checking7. Port number’s scop e is ____ to ____.A 0, 1023B 0, 65535C 0, 127D 0,2558. The port numbers ranging from ____to ____ are called well-known port number and are restricted.A 0, 1023B 0, 65535C 0, 127D 0,2559. UDP socket identified by two components, they are ____.A source IP addresses and source port numbersB source IP addresses and destination IP addressesC destination IP address and destination port numbersD destination port numbers and source port numbers10. TCP socket identified by a (an) ____.A 1-tupleB 2-tupleC 3-tupleD 4-tuple11. Which of the following applications normally uses UDP services?A SMTPB Streaming multimediaC FTPD HTTP12. Reliable data transfer protocol over a perfectly reliable channel is____.A rdt1.0B rdt2.0C rdt3.0D rdt2.113. Reliable data transfer protocol over a channel with bit errors and packet losses is _ ___.A rdt1.0B rdt2.0C rdt3.0D rdt2.114. Which of the following about reliable data transfer over a channel with bit errors i s not correct?A RDT2.0: assuming ACK and NAK will not be corruptedB RDT2.1: assuming ACK and NAK can be corruptedC RDT2.2: only use ACK-sD RDT2.2: use both ACK-s and NAK-s15. Which of the following protocols is not pipelining protocols?A TCPB rdt3.0C GO-BACK-ND selective repeat16. Which of the following is not correct about GBN protocol?A Only using ACK-sB Using cumulative ACK-sC Receiver discards all out-of-order packetsD It is not pipelined protocol17. Which of the following is not correct about SR protocol?A receiver individually acknowledges all correctly received packetsB sender only resends packets for which ACK not receivedC It limits sequence number of sent but un-ACK-ed packetsD It is not a pipelined protocol18. Which of the following about TCP connection is not correct?A It is a broadcast connectionB It is a point-to-point connectionC It is a pipelined connectionD It is a full duplex connection19. The SYN segment is used for____.A TCP connection setupB TCP flow controlC TCP congestion controlD Closing a TCP connection20. The FIN segment is used for____.A TCP connection setupB TCP flow controlC TCP congestion controlD Closing a TCP connection21.How does TCP sender perceive congestion?A Through a timeout eventB Through a receiving duplicate ACK-s eventC Both A and BD Either A or B22. Extending host-to-host delivery to process-to-process delivery is called transport-layer ____ and .A multiplexing and de-multiplexingB storing and forwardingC forwarding and filteringD switching and routing23. UDP is a ____ service while TCP is a connection-oriented service.A ConnectionlessB ReliableC Connection-orientedD In-order24. The UDP header has only four fields, they are____.A Source port number, destination port number, length and checksumB Source port number, destination port number, source IP and destination IPC source IP, destination IP, source MAC address and destination MAC addressD source IP, destination IP, sequence number and ACK sequence number25. There are two 16-bit integers: 1110 0110 0110 0110, 1101 0101 0101 0101. Their checksum is____.A 0100010001000011B 1011101110111100C 1111111111111111D 100000000000000026.The maximum amount of data that can be grabbed and placed in a segment is limited by the____.A Maximum segment size (MSS)B MTUC ChecksumD Sequence number27.The MSS is typically set by first determining the length of the largest link-layer frame that can be sent by the local sending host----the so-called____.A Maximum transmission unit (MTU)B MSSC ChecksumD Sequence number28. A File size of 500,000bytes, MSS equals 1000bytes. When we want to transmit this file with TCP, the sequence number of the first segment is 0, and the sequence number of the second segment is ____.A 1000B 999C 1001D 50000029.Because TCP only acknowledges bytes up to the first missing byte in the stream, TCP is said to provide____.A Cumulative acknowledgementsB Selective acknowledgementsC 3 duplicate ACKsD positive ACKs30. Provided α=0.125, current value of Estimated-RTT is 0.4s, Sample-RTT is 0.8s, then the new value of Estimated-RTT is ____s.A 0.45B 0.6C 0.7D 0.831.Provided RcvBuffer=20,LastByteRcvd=20,LastByteRead=15, thenRcvWindow=____.A 14B 15C 16D 1032. TCP service does not provide____.A Reliable data transferB Flow controlC Delay guaranteeD Congestion control33. There are two states in TCP congestion control, which are ____.A slow start and congestion avoidanceB safe start and congestion avoidanceC slow start and congestion abandonD safe start and congestion abandon34. The transport-layer protocol provides logical communication between ____, and the network-layer protocol provides logical communication ____.A hosts, processesB processes, hostsC threads, processesD processes, threads35. To implement the multicast services the Internet employs the ____ protocol.A FTPB TCPC IGMPD UDP36. If an application developer chooses ____ protocol, then the application process is almost directly talking with IP.A HTTPB RIPC CSMA/CDD UDP37. ____ maintains connection-state in the end systems. This connection state includes receive and send buffers, congestion-control parameters, and sequence and acknowledgment number parameters.A UDPB TCPC DNSD HTTP38. The host that initiates the session in the Internet is labeled as ____.A serverB user agentC clientD router39. With TCP there is no _____ between sending and receiving transport-layer entities.A flow controlB handshakingC. congestion control D VC setup40. The Internet’s ____service helps prevent the Internet from entering a state of gridlock.A datagramB congestion controlC sliding windowD timeout event41. Connection setup at the transport layer involves ____.A serverB only the two end systemsC clientD router42. A ____layer protocol provides for logical communication between applications.A transportB applicationC networkingD MAC43. In static congestion window, if it satisfies W*S/R > RTT + S/R, the Latency is ____.A W*S/R – ( RTT+ S/R)B 2RTT + O/RC 2RTT + O/R + (k-1)[W* S/R- (RTT + S/R)]D 2RTT + S/R44. The receive side of transport layer reassembles segments into messages, passes to ____layer.A ApplicationB NetworkingC PhysicalD MAC45. In the following four options, which one is correct?A The variations in the SampleRTT are smoothed out in the computation of the EstimatedRTTB The timeout should be less than the connection’s RTTC Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Then the current value of TimeoutInterval will necessarily be≥1 secD Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Then the current value of TimeoutInterval will necessarily be≤1 sec46. The port number used by HTTP is ____.A 80B 25C 110D 5347. The port number used by SMTP is ____.A 80B 25C 110D 5348. The port number used by pop3 is ____.A 80B 25C 110D 5349. The port number used by DNS is ____.A 80B 25C 110D 5350. The port number used by FTP is ____.A 20 and 21B 20C 21D 5351. A UDP socket identified by a ____ tuple(s).A 2B 4C 1D 352. A TCP socket identified by a ____ tuple(s).A 2B 4C 1D 353. A TCP socket does not include____.A Source MAC addressB Source port numberC Destination IP addressD Destination port number54. Which of following about UDP is not correct.A It is a reliable data transfer protocolB It is connectionlessC no handshaking between UDP sender, receiverD it is a best effort service protocol55. DNS uses ____ service.A TCPB UDPC Both TCP and UDPD None of above56. Which of following about UDP is correct?A Finer application-level control over what data is sent, and whenB No connection establishment (which can add delay), so no delay for establish a connectionC No connection state (so, UDP can typically support many active clients)D Large packet header overhead (16-B)57. Streaming media uses a ____ service normally.A TCPB UDPC Both TCP and UDPD None of above58. The UDP header has only ____ fields.A 2B 4C 1D 359. Which of the following does not included in UDP header.A Source port numberB Destination port numberC ChecksumD Sequence number60. Which of the following is not a pipelining protocol.A Rdt1.0B Go-Back-NC Selective repeatD TCP61. In the following four descriptions about MSS and MTU, which one is not correct?A The MSS is the maximum amount of application-layer data in the segmentB The MSS is the maximum size of the TCP segment including headersC The MSS is typically set by MTUD The MTU means the largest link-layer frame62. The job of gathering data chunks, encapsulating each data chunk with header information to create segments and passing the segments to the network is called ____.A multiplexingB de-multiplexingC forwardingD routing63. In the following four descriptions about the relationship between the transport layer and the network layer, which one is not correct?A The transport-layer protocol provides logical communication between hostsB The transport-layer protocol provides logical communication between processesC The services that a transport-layer protocol can provide are often constrained by the service model of the network-layer protocolD A computer network may make available multiple transport protocols64. Suppose the following three 8-bit bytes: 01010101, 01110000, 01001100. What’s the 1s complement of the sum of these 8-bit bytes?A 00010001B 11101101C 00010010D 1000100065. The following four descriptions about multiplexing and de-multiplexing, which one is correct?A A UDP socket is identified by a two-tuples consisting of a source port number and a destination port number.B If two UDP segment have different source port number, they may be directed to the same destination process.C If two TCP segments with different source port number, they may be directed to the same destination process.D If two TCP segments with same destination IP address and destination port number, they must be the same TCP connection.66. UDP and TCP both have the fields except ____.A source port numberB destination port numberC checksumD receive window67. If we define N to be the window size, base to be the sequence number of the oldest unacknowledged packet, and next-seq-num to be the smallest unused sequence number, then the interval [nextseqnum,base+N-1] corresponds to packet that ____.A can be sent immediatelyB have already been transmitted and acknowledgedC cannot be usedD have been sent but not yet acknowledged68. Which of the following about TCP is not correct?A It is a connectionless protocolB Point-to-point protocolC Reliable, in-order byte steam protocolD Pipelined protocol69. Which of the following about TCP is not correct?A It is a connectionless protocolB full duplex data transfer protocolC connection-oriented protocolD flow controlled protocol70. The maximum amount of data that can be grabbed and placed in a segment is limited by the ____.A Maximum segment size (MSS)B MTUC Sequence numberD Check sum71. The MSS is typically set by first determining the length of the largest link-layer frame that can be sent by the local sending host (the so-called____), and then will fit into a single link-layer frame.A Maximum segment size (MSS)B MTUC Sequence numberD Check sum72. The MSS is the maximum amount of ____layer data in the segment, not the maximum size of the TCP segment including headers.A ApplicationB TransportC NetworkingD Link73. Which of the following field is not used for connection setup and teardown?A Sequence numberB TSTC SYND FIN74. ____ is the byte stream number of first byte in the segment.A Sequence numberB ACK numberC ChecksumD port number75. ____ is the byte sequence numbers of next byte expected from other side.A Sequence numberB ACK numberC ChecksumD port number76. Because TCP only acknowledges bytes up to the first missing byte in the stream, TCP is said to provide ____ acknowledgements.A CumulativeB SelectiveC SingleD Negative77. Fast retransmit means in the case that ____ duplicate ACK-s are received, the TCP sender resend segment before timer expires.A 3B 4C 5D 678. TCP____ means sender won’t overflow receiver’s buffer by tran smitting too much, too fast.A Flow controlB Congestion controlC Reliable data transferD Connection-oriented service79. TCP provides flow control by having the sender maintain a variable called the ____.A Receive windowB Congestion windowC Sliding windowD buffer80. How does TCP sender perceive congestion?A TimeoutB 3 duplicate ACK-sC Both A and BD None of above81. Transport protocols run in ____.A ServersB ClientsC RoutersD End systems82. Which of the following services is not provided by TCP?A Delay guarantees and bandwidth guaranteesB Reliable data transfers and flow controlsC Congestion controlsD In-order data transfers83. Which service does UDP not provide?A multiplexingB de-multiplexingC error-detectionD error-correction84. There are three major events related to data transmission and retransmission in the TCP sender, which one is not in it?A data received from application aboveB de-multiplexing segmentC timer timeoutD ACK receipt85. Which of the following applications normally uses UDP services?A SMTPB Streaming multimediaC FTPD HTTP86. Which of the following about TCP connection is not correct?A It is a broadcast connectionB It is a point-to-point connectionC It is a pipelined connectionD It is a full duplex connection87. The SYN segment is used for____.A TCP connection setupB TCP flow controlC TCP congestion controlD Closing a TCP connection88. Which service helps prevent the internet from entering a state of gridlock?A reliable data transferB flow controlC congestion controlD handshaking procedure89. The Internet’s _____is responsible for moving packets from one host to another.A application layerB transport layerC network layerD link layer90.In the following applications, which one is a bandwidth-sensitive application?A E-mailB web applicationC real-time audioD file transfer91. In the following applications, which one uses UDP?A E-mailB web applicationC file transferD DNS92. In the following four descriptions, which one is correct?A If one host’s transport layer uses TCP, then its network layer must use virtual-circuit network.B Datagram network provides connection serviceC The transport-layer connection service is implemented in the routerD The network-layer connection service is implemented in the router as well as in the end system.93.____ is a speeding-matching service---matching the rate which the sender is sending against the rate at which the receiving application is reading.A congestion controlB flow controlC sliding-window controlD variable control94. In the following four descriptions about Rcv-Window, which one is correct?A The size of the TCP RcvWindow never changes throughout the duration of the connectionB The size of the TCP RcvWindow will change with the size of the TCP RcvBufferC The size of the TCP RcvWindow must be less than or equal to the size of the TCP RcvBufferD Suppose host A sends a file to host B over a TCP connection, the number of unacknowledged bytes that A sends cannot exceed the size of the size of the RcvWindow.95. There are 6 flag fields. Which one is to indicate that the receiver should pass the data to the upper layer immediately?A PSHB URGC ACKD RST96. Suppose the TCP receiver receives the segment that partially or completely fills in gap in received data, it will ____.A immediately send ACKB immediately send duplicate ACKC wait some time for arrival of another in-order segmentD send single cumulative97. _____ imposes constrain on the rate at which a TCP sender can send traffic into the network.A sliding windowB congestion windowC receive windowD variable window98. Flow control and congestion control are same at that they all limit the rate of the sender, but differ in that ____.A flow control limits its rate by the size of RcvWindow, but congestion control by the traffic on the linkB congestion control limits its rate by the size of RcvWindow, but flow control by the traffic on the linkC flow control mainly is accomplished by the sender, but congestion control by the receiver.D flow control mainly is accomplished by the receiver, but congestion control bythe link.99. This job of delivering the data in a transport-layer segment to the correct socket is called ____.A multiplexingB de-multiplexingC forwardingD routing100. If we define N to be the window size, base to be the sequence number of the oldest unacknowledged packet, and next-seq-num to be the smallest unused sequence number, then the interval [base, nextseqnum-1] corresponds to packet that ____.A can be sent immediatelyB have already been transmitted and acknowledgedC cannot be usedD have been sent but not yet acknowledged101. ____ are the two types of transport services that the Internet provides to the applications.A TCP and UDPB connection-oriented and connectionless serviceC TCP and IPD reliable data transfer and flow control102. In the following descriptions about persistent connection, which one is not correct?A The server leaves the TCP connection open after sending a responseB Each TCP connection is closed after the server sending one objectC There are two versions of persistent connection: without pipelining and with pipeliningD The default mode of HTTP uses persistent connection with pipelining103. The field of Length in UDP segment specifies the length of ____.A the UDP segment, not including the headerB the UDP segment, including the headerC the UDP segment’s headerD the Length field104. In TCP segment header, which field can implement the reliable data transfer?A source port number and destination port numberB sequence number and ACK numberC urgent data pointerD Receive window105. In the following four descriptions about TCP connection management, which one is not correct?A Either of the two processes participating in a TCP connection can end the connectionB If the FIN bit is set to 1, it means that it wants to close the connectionC In the first two step of the three-way handshake, the client and server randomly choose an initial sequence numberD In the three segments of the three-way handshake, the SYN bit must be set to 1 106. Suppose host A sends two TCP segments back to back to host B over a TCP connection. The first segment has sequence number 42, and the second has sequence number 110. If the 1st is lost and 2nd arrives at host B. What will be the acknowledgment number?A 43B ACK42C 109D ACK1101.Consider sending an object of size O=500,000bytes from server to client. LetS=500 bytes and RTT=0.2s. Suppose the transport protocol uses static windows with window size 5. For a transmission rate of 100Kbps, determine the latency for sending the whole object. Recall the number of windows K=O/ WS), and there is K-1 stalled state (that is idle time gaps).2.Consider the following plot of TCP congestion window size as a function of time.Fill in the blanks as follow:a) The initial value of Threshold at the first transmission round is ____. b) The value of Threshold at the 11st transmission round is ____. c) The value of Threshold at the 21st transmission round is ____. d) After the 9th transmission round, segment loss detected by ____.(A) Timeout(B) Triple duplicate ACKe) After the 19th transmission round, segment loss detected by ____.(A) Timeout(B) Triple duplicate ACKf) During ____ transmission round, the 18th segment is sent.3.Consider the TCP reliable data transfer in the given graph. If in Segment 1’s Sequence number =10,data=“AC”, please fill in the following blanks. a) In Segment 2, ACK number=____;b) In Segment 3, Sequence number =____; data=“0123456789”c) If there are some bits corrupted in segment 3 when it arrives Host B, then the ACK number in Segment 5 is ____; and the ACK number in Segment 6 is ____.14 180 26 3000 2 6 4 8 10 12 16 20 22 240 28 32Congestion window sizeTransmission round48121612345674. The client A wants to request a Web page from Server B. Suppose the URL of the page is 172.16.0.200/experiment, and also it wants to receive French version of object. The time-sequence diagram is shown below, please fill in the blanks.12345Packet① to Packet③are TCP connection’s segment, then:Packet ①: SYN flag bit= aACK flag bit= bSequence number= 92Packet ②: SYN flag bit=1ACK flag bit= c Sequence number=100 Packet ③: SYN flag bit= d ACK flag bit=1Sequence number= e5. Consider sending an object of size O=100 Kbytes from server to client. Let S=536 bytes and RTT=100msec. Suppose the transport protocol uses static windows with window size W.(1) For a transmission rate of 25 kbps, determine the minimum possible latency. Determine the minimum window size that achieves this latency. (2) Repeat (1) for 100 kbps.6. Consider the following plot of TCP congestion window size as a function of time. Please fill in the blanks as below.a) The initial value of Threshold at the first transmission round is____. b) The value of Threshold at the 11th transmission round is_____. c) The value of Threshold at the 21st transmission round is_____.14 18 26 30 0 2 6 4 8 10 12 16 20 22 24 28 32 Congestion window sizeTransmission round481216d) After the 9th transmission round, _____ occurs.e) After the 19th transmission round, ____ are detected.。

计算机网络英文题库(附答案)chapter1

计算机网络英文题库(附答案)chapter1

Chapter 1 Computer Networks and the Internet 1.The The ( ( ) ) is is is a a a worldwide worldwide worldwide computer computer computer network, network, network, that that that is, is, is, a a a network network network that that interconnects millions of computing devices throughout the world. ppt3 A public Internet B Intranet C switch net D television net 2.Which kind of media is not a guided media? ( ) A twisted-pair copper wire B a coaxial cable C fiber optics D digital satellite channel 3.Which kind of media is a guided media? ( ) A geostationary satellite B low-altitude satellite C fiber optics D wireless LAN 4.The units of data exchanged by a link-layer protocol are called ( ). A Frames B Segments C Datagrams D bit streams 5.Which of the following option belongs to the circuit-switched networks? ( ) A FDM B TDM C VC networks D both A and B 6.( )makes sure that that neither neither neither side side side of of of a a a connection overwhelms connection overwhelms the the other other side by sending too many packets too fast. A Reliable data transfer B Flow control C Congestion control D Handshaking procedure 7.( ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link. A Store-and-forward transmission B FDM C End-to-end connection D TDM 8.Datagram networks and virtual-circuit networks differ in that ( ). A datagram networks are circuit-switched networks, and virtual-circuit networks are packet-switched networks. B datagram networks are packet-switched networks, and virtual-circuit networks are circuit-switched networks. C datagram networks use destination addresses and virtual-circuit networks use VC. numbers to forward packets toward their destination. D datagram networks use VC. numbers and virtual-circuit networks use destination addresses to forward packets toward their destination. 9.In the following options, which one is not a guided media? ( ) A twisted-pair wire B fiber optics C coaxial cable D satellite 10.Processing delay does not include the time to ( ). A examine the packet ’s header B wait to transmit the packet onto the link C determine where to direct the packet D check bit-error in the packet 11.In the following four descriptions, which one is correct? ( ) A The traffic intensity must be greater than 1. B The fraction of lost packets increases as the traffic intensity decreases. C If the traffic intensity is close to zero, the average queuing delaywill be close to zero. D If the traffic intensity is close to one, the average queuing delay will be close to one. 12.The The Internet Internet Internet’’s s network network network layer layer layer is is is responsible responsible responsible for for for moving moving moving network-layer network-layer packets known as ( ) from one host to another. A frame B datagram C segment D message 13.The protocols of various layers are called ( ). A the protocol stack B TCP/IP C ISP D network protocol 14.There are two classes of packet-switched networks: ( ) networks and virtual-circuit networks. A datagram B circuit-switched C television D telephone 15.Access networks can be loosely classified into three categories: residential access, company access and ( ) access. A cabled B wireless C campus D city area Question 16~17 Suppose, a is the average rate at which packets arrive at the queue, R is the the transmission transmission transmission rate, rate, rate, and and and all all all packets packets packets consist consist consist of of L bits, bits, then then then the the the traffic traffic intensity is ( 16 ), and it should no greater than ( 17 ). 16. A LR /aB La /RC Ra /L D LR /a 17.A 2 B 1 C 0 D -1 18.In the Internet, the equivalent concept to end systems is ( ). A hosts B servers C clients D routers 19.In the Internet, end systems are connected together by ( ). A copper wire B coaxial cable C communication links D fiber optics 20.End systems access to the Internet through its ( ). A modems B protocols C ISP D sockets 21.End systems, packet switches, and other pieces of the Internet, run ( ) that control the sending and receiving of information within the Internet. A programs B processes C applications D protocols 22.There are many private networks, such as many corporate and government networks, whose hosts cannot exchange messages with hosts outside of the private network. These private networks are often referred to as ( ). A internets B LANC intranets D W AN 23.The internet allows ( ) running on its end systems to exchange data with each other. A clients applications B server applications C P2P applications D distributed applications 24.The Internet provides two services to its distributed applications: a connectionless unreliable service and () service. A flow control B connection-oriented reliable C congestion control D TCP 25.It defines the format and the order of messages exchanged between twoor more communicating entities, as well as the actions taken on the transmission and/or receipt of a message or other event. The sentence describes ( ). A Internet B protocol C intranet D network 26.In the following options, which does not define in protocol? ( ) A the format of messages exchanged between two or more communicating entities B the order of messages exchanged between two or more communicating entities C the actions taken on the transmission of a message or other evenD the transmission signals are digital signals or analog signals 27.In the following options, which is defined in protocol? ( ) A the actions taken on the transmission and/or receipt of a message oother event B the objects exchanged between communicating entities C the content in the exchanged messages D the location of the hosts 28.In the following options, which does not belong to the network edge( ) A end systems B routers C clients D servers 29.In the following options, which belongs to the network core? ( ) A end systems B routers C clients D servers 30.In the following options, which is not the bundled with the Internet ’s connection-oriented service? ( ) A reliable data transfer B guarantee of the transmission time C flow control D congestion-control 31.An application can rely on the connection to deliver all of its data without error and in the proper order. The sentence describes ( ). A flow control B congestion-control C reliable data transfer D connection-oriented service 32.It makes sure that neither side of a connection overwhelms the other side by sending too many packets too fast. The sentence describes ( ). A flow control B congestion-control C connection-oriented service D reliable data transfer 33.It helps prevent the Internet from entering a state of gridlock. When a packet switch becomes congested, its buffers can overflow and packet loss can occur. The sentence describes ( ). A flow control B congestion-control C connection-oriented service D reliable data transfer 34.The Internet ’s connection-oriented service has a name, it is ( ). A TCP B UDP C TCP/IP D IP 35.In In the the the following following following options, options, options, which which which service service service does does does not not not be be be provided provided provided to to to an an application by TCP?( ) A reliable transport B flow control C video conferencing D congestion control 36.The Internet ’s connectionless service is called ( ). A TCP B UDP C TCP/IP D IP 37.In the following options, which does not use TCP?( ) A SMTP B internet telephone C FTP D HTTP 38.In the following options, which does not use UDP?( ) A Internet phone B video conferencing C streaming multimedia D telnet 39.There are two fundamental approaches to building a network core, ( ) and packet switching. A electrical current switching B circuit switching C data switching D message switching 40.In ( ) networks, the resources needed along a path to provide for communication between the end system are reserved for the duration ofthe communication session. A packet-switched B data-switched C circuit-switched D message-switched 41.In ( ) networks, the resources are not reserved; a session’s messages use the resources on demand, and as a consequence, may have to wait for access to communication link. A packet-switched B data-switched C circuit-switched D message-switched 42.In a circuit-switched network, if each link has n circuits, for each link used by the end-to-end connection, the connection gets ( ) of the link link’’s bandwidth for the duration of the connection. A a fraction 1/n B all C 1/2 D n times 43.For ( ), the transmission rate of a circuit is equal to the frame rate multiplied by the number of bits in a slot. A CDMA B packet-switched network C TDM D FDM 44.( ) means that the switch must receive the entire packet before it canbegin to transmit the first bit of the packet onto the outbound link. A Queuing delay B Store-and-forward transmission C Packet loss D Propagation 45.The network that forwards packets according to host destination addresses is called ( ) network. A circuit-switched B packet-switched C virtual-circuit D datagram 46.The network that forwards packets according to virtual-circuit numbers is called ( ) network. A circuit-switched B packet-switched C virtual-circuit D datagram 47.In the following entries, which is not a kind of access network?( ) A residential access B company access C wireless access D local access 48.Suppose there is exactly one packet switch between a sending host and a receiving host. The transmission rates between the sending host and the switch and between the switch and the receiving host are R 1 and R 2, respectively. Assuming that the switch uses store-and-forward packet switching, what is the total end-to-end delay to send a packet of length L ? (Ignore queuing delay, propagation delay, and processing delay.) ( )A L /R 1+L /R 2 B L /R 1C L /R 2D none of the above 49.The time required to examine the packet ’s header and determine where to direct the packet is part of the ( ). A queuing delay B processing delay C propagation delay D transmission delay 50.The time required to propagate from the beginning of the link to the next router is ( ). A queuing delay B processing delay C propagation delay D transmission delay 51.Consider sending a packet of 3000bits over a path of 5 links. Each link transmits transmits at at at 1000bps. 1000bps. 1000bps. Queuing Queuing Queuing delays, delays, delays, propagation propagation propagation delay delay delay and and and processing processing delay are negligible. (6 points) (1).Suppose (1).Suppose the the the network network network is is is a a a packet-switched packet-switched packet-switched virtual virtual virtual circuit circuit circuit network. network. network. VC VC setup time is 0.1 seconds. Suppose the sending layers add a total of 500 bits of header to each packet. How long does it take to send the file from source to destination? (2).Suppose the the network network network is is is a a a packet-switched packet-switched datagram datagram network network network and and and a a connectionless connectionless service service service is is is used. used. used. Now Now Now suppose suppose suppose each each each packet packet packet has has has 200 200 200 bits bits bits of of header. How long does it take to send the file? (3).Suppose that the network is a circuit-switched network. Further suppose that that the the the transmission transmission transmission rate rate rate of of of the the the circuit circuit circuit between between between source source source and and and destination destination destination is is 200bps. Assuming 0.02s setup time and 200 bits of header appended to the packet, how long does it take to send the packet? Solution: (1). t=5*(3000+500)/1000+0.1=17.6s(2). t=5*(3000+200)/1000=16s(3). t=(3000+200)/200+0.02=16.02s。

计算机网络英文复习题

计算机网络英文复习题

计算机网络英文复习题1、请简述英文“network”是什么含义?并举出一个具体的网络应用实例。

“Network”的英文意思是网络。

网络是由多个节点(nodes)通过各种协议(protocols)进行连接,以实现信息的交换和共享的一种系统。

网络应用实例包括:电子邮件(Email)、万维网(World Wide Web)、文件传输(FTP)、远程登录(Telnet)等。

2、什么是局域网(Local Area Network,LAN)?请举例说明。

局域网(LAN)是一种在有限区域内(如一座大楼、一个校园或一个工厂等)连接计算机和其他设备的高速网络。

例如,家庭网络、办公室网络和校园网络等都是局域网的例子。

3、什么是广域网(Wide Area Network,WAN)?请举例说明。

广域网(WAN)是一种跨越较大地理范围的网络,通常由多个局域网组成,并通过各种传输媒介(如光纤、卫星等)连接在一起。

例如,因特网(Internet)就是一种广域网的例子。

4、请简述TCP/IP协议是什么?并列举其中两个主要的协议。

TCP/IP协议是一种在网络通信中广泛使用的协议套件,它包含了传输控制协议(TCP)和互联网协议(IP)。

这两个协议是TCP/IP协议的重要组成部分。

此外,TCP/IP协议还包括其他一些协议,如HTTP、FTP等。

5、什么是IP?请简述其结构。

IP是互联网协议(IP)中用来唯一标识网络主机或设备的。

它通常由四个数字组成,每个数字在0-255之间。

这些数字由点号分隔,形如 x.x.x.x。

例如,192.168.1.1就是一个IP的例子。

6、什么是DNS?请简述其作用。

DNS(Domain Name System)是域名系统,它可以将网站的域名解析为对应的IP,从而让用户可以通过域名访问网站。

DNS的作用是在用户访问网站时进行解析,将域名转化为对应的IP,这样用户就可以通过浏览器访问网站了。

计算机网络复习题一、选择题1、OSI模型将计算机网络分为几个层次?A. 4个B. 6个C. 7个D. 8个2、TCP/IP协议包含哪两个主要的协议?A. TCP和HTTPB. TCP和UDPC. HTTP和FTPD. FTP和SMTP3、以下哪个协议用于传输电子邮件?A. SMTPB. IMAPC. POP3D. FTP4、以下哪个网络设备用于将网络分成若干个子网?A.路由器B.交换机C.网关D.集线器5、以太网使用什么类型的传输方式?A.异步传输B.同步传输C.基带传输D.宽带传输二、填空题1、OSI模型的第一层是_________层,负责在计算机之间建立连接。

计算机网络英文试题

计算机网络英文试题

Computer Network Test Paper1.Who invented IP and some related Internet protocols?Ba)Vinton Cerf and Bob Metcalfeb)Vinton Cerf and Robert Kahnc)Bob Metcalfe and Ivan Sutherlandd)Bob Metcalfe and David Clark2.In the OSI reference model,3.The upper layers of the OSI model are, in correct order Ba)Session, application, presentationb)Session, presentation, applicationc)Session, application, presentation, physicald)Application, presentation, session4.The lower layers of the OSI model are, in correct order Da)physical, system, network, logicalb)physical, logical, network, systemc)physical, transport, network, data linkd)physical, data link, network, transport5.The Internet Protocol (IP) generally corresponds to which OSI layer?Aa)Network (layer three)b)Transport (layer four)c)Data link (layer two)d)Session (layer five)6.MTU stands for Ca)Minimum Transfer Unitb)Minimum Transmission Unitc)Maximum Transmission Unitd)Maximum Transfer Unit7.What layer of the OSI model is designed to perform error detection functions?Ba)Physicalb)Data linkc)Networkd)transport8.Which of these network devices primarily functions at the OSI Network layer (layer 3)?Ca)Switchb)Gatewayc)Routerd)All of the above9.What is the size of today’s standard (IPv4) IP address?Aa) 4 bytes (32 bits)b)12 bytes (96 bits)c)15 bytes (120 bits)d)16 bytes (128 bits)10.What is the size of the next-generation (IPv6) IP address?a) 4 bytes (32 bits)b)12 bytes (96 bits)c)15 bytes (120 bits)d)16 bytes (128 bits)11.Which of the following higher-level protocols runs over IP?Da)FTPb)HTTPc)SMTPd)All of the above12.Which of the following IPv4 addresses is the loopback address?C13.of the following IPv6 addresses is the loopback address?Ba)0::0b)0::1c)127::0d)127::114.The length of an IP datagram header can vary depending on the options used. What is thesmallest possible IP header size?Ba)16 bytesb)20 bytesc)24 bytesd)60 bytes15.The source IP address for an IPv4 datagram is stored where in the header?Ca)2nd longword (bytes 5-8)b)3rd longword (bytes 9-12)c)4rd longword (bytes 13-16)d)5rd longword (bytes 17-20)16.The destination IP address for an IPv4 datagram is stored where in the header?Da)2nd longword (bytes 5-8)b)3rd longword (bytes 9-12)c)4rd longword (bytes 13-16)d)5rd longword (bytes 17-20)17.The header length field in an IPv4 datagram contains the size of an IP header measured innumber of Ca)Bitsb)Bytesc)Longwords (4 bytes)d)None of the above18.Can IP run over any other physical networks besides Ethernet?Da)No (and IP does not run over Ethernet)b)Noc)Yes (but IP does not run over Ethernet)d)Yes19.What function does Address Resolution Protocol (ARP) perform?Aa)Converts IP addresses to Ethernet addressesb)Automatically assigns IP addresses to computersc)Prevents two computers from using the same IP addressd)None of the above20.What mechanism does ARP use to resolve IP addresses?Ba)Mathematical formulab)Lookup tablec)Central web sited)Random number generator21.Which utility program is designed to report whether a networked computer is responding ata given IP address, and how long these responses take?Ba)tracerouteb)pingc)ttcpd)netstate22.which of these shell commands supplies the IP address of a computer running the Linuxoperating system?Ba)ipconfigb)ifconfigc)linuxconfd)none of the above23.Which of the following technologies manage the conversion between IP addresses and hostnames?Ba)BGPb)DNSc)ARPd)All of the above24.CIDR stands for Da)Class-based Internet Domain Routingb)Careful Inter-Domain Routingc)Constant Internet Domain Routingd)Classless Inter-Domain Routing25.In CIDR notation, which of the following networks contains host B26.central authority is responsible for allocating IP addresses on the Internet?Ba)IETFb)IANAc)IEEEd)None of the above27.The IP delivery service is Ca)Reliable, connection-orientedb)Non-routablec)Unreliable, connectionlessd)None of the above28.TCP stands for Aa)Transmission Control Protocolb)Trivial Connection Protocolc)Traffic Control Protocold)Telephony Connection Protocol29.UDP stands for Ca)Universal Data Protocolb)Unreliable Datagram Protocolc)User Datagram Protocold)Ultimate Data Protocol30.Both TCP and UDP belong to which layer of the OSI mode?Ba)Sessionb)Transportc)Networkd)Data Link31.UDP offers which of the following benefits relative to TCP?Aa)UDP consumes fewer computer resources by not maintaining connection stateb)UDP supports a self-regulating “throttle” feature that prevents network saturationc)UDP guarantees that Individual packets of a transmission will arrive “in order”d)None of the above32.What is the maximum recommended length of twisted-pair Ethernet cables used in home orbusiness networks?Ba)10 metersb)100 metersc)1000 metersd)Other33.On Ethernet LANs, the Ethernet address is also known as the Ba)IP addressb)MAC addressc)Virtual addressd)Other34.How long is a MAC address?Ba) 4 bytesb) 6 bytesc)8 bytesd)10 bytes35.What is the basic unit of Ethernet traffic?Ba)Fileb)Framec)Packetd)Stream36.CSMA/CD stands for Aa)Carrier Sense Multiple Access with Collision Detectionb)Collision Sense Multiple Access with Carrier Detectionc)Carrier Single-Multiple Access with Collision Detectiond)Collision Single-Multiple Access with Carrier Detection37.Which of the following is a routing protocol?a)ARPb)DNSc)BGPd)SMTP38.Which of the following algorithm has the so called count-to-infinity problem?Ca)Flooding algorithmb)Link-state algorithmc)Distance vector algorithmd)None of the above39.Which of the following algorithm does BGP use?Ca)Flooding algorithmb)Link-state algorithmc)Distance vector algorithmd)None of the above40.Which of the following protocol does ICMP run over?Ca)TCPb)UDPc)IPd)Ethernet41.Which of the following describes the TCP connection establishing mechanism?Ca)One-way-handshakeb)Two-way-handshakec)Three-way-handshaked)Four-way-handshake。

计算机网络英文题库(附答案)chapter1

计算机网络英文题库(附答案)chapter1

计算机网络英文题库(附答案)chapter1Chapter 1 Computer Networks and the Internet networks use VC. numbers to forward packets toward their1.The ( ) is a worldwide computer network, that is, a network that destination.interconnects millions of computing devices throughout the world. D datagram networks use VC. numbers and virtual-circuit networks ppt3 use destination addresses to forward packets toward their destination.A public Internet 9.In the following options, which one is not a guided media? ( )B Intranet A twisted-pair wireC switch net B fiber opticsD television net C coaxial cable2.Which kind of media is not a guided media? ( ) D satelliteA twisted-pair copper wire 10.Processing delay does not include the time to ( ).B a coaxial cable A examine the packet’s headerC fiber optics B wait to transmit the packet onto the linkD digital satellite channel C determine where to direct the packetD check bit-error in the packet3.Which kind of media is a guided media? ( )11.In the following four descriptions, which one is correct? ( )A geostationary satelliteB low-altitude satelliteC fiber opticsD wireless LAN A The traffic intensity must be greater than 1.B The fraction of lost packets increases as the traffic intensity decreases.C If the traffic intensity is close to zero, the average queuing delay 4.The units of data exchanged by a link-layer protocol are called ( ).will be close to zero. A FramesD If the traffic intensity is close to one, the average queuing delay B Segmentswill be close to one. C Datagrams12.The Internet’s network layer is responsible for moving network-layer D bit streamspackets known as ( ) from one host to another. 5.Which of the following option belongs to the circuit-switched networks?A frame ( )B datagram A FDMC segment B TDMD message C VC networks13.The protocols of various layers are called ( ). D both A and BA the protocol stack 6.( )makes sure that neither side of a connection overwhelms the otherB TCP/IPside by sending too many packets too fast.C ISPA Reliable data transferD network protocolB Flow control14.There are two classes of packet-switched networks: ( ) networks andC Congestion controlvirtual-circuit networks.D Handshaking procedureA datagram7.( ) means that the switch must receive the entire packet before it canB circuit-switchedbegin to transmit the first bit of the packet onto the outbound link.C television A Store-and-forward transmissionB FDMD telephoneC End-to-end connection 15.Access networks can be loosely classified into three categories:D TDM residential access, company access and ( ) access.8.Datagram networks and virtual-circuit networks differ in that ( ).A cabledA datagram networks are circuit-switched networks, andB wirelessvirtual-circuit networks are packet-switched networks.B datagram networks are packet-switched networks, andC campusD city areavirtual-circuit networks are circuit-switched networks.Question 16~17 C datagram networks use destination addresses and virtual-circuit1D distributed applicationsSuppose, a is the average rate at which packets arrive at the queue, R is24.The Internet provides two services to its distributed applications: a the transmission rate, and all packets consist of L bits, then the trafficintensity is ( 16 ), and it should no greater than ( 17 ). connectionless unreliable service and () service.A flow control16. A LR/aB connection-oriented reliableB La/RC congestion controlC Ra/LD TCP25.It defines the format and the order of messages exchanged between twoD LR/aor more communicating entities, as well as the actions taken on the 17.A 2B 1 transmission and/or receipt of a message or other event. The sentence describes ( ).C 0A InternetD -1B protocol 18.In the Internet, the equivalent concept to end systems is ( ).C intranet A hostsD network B servers26.In the following options, which does not define in protocol? ( )C clientsA the format of messages exchanged between two or moreD routerscommunicating entities 19.In the Internet, end systems are connected together by ( ).B the order of messages exchanged between two or more A copper wirecommunicating entities B coaxial cableC the actions taken on the transmission of a message or other eventC communication linksD the transmission signals are digital signals or analog signals 模拟 D fiber optics信号20.End systems access to the Internet through its ( ).27.In the following options, which is defined in protocol? ( ) A modemsA the actions taken on the transmission and/or receipt of a message orB protocolsother eventC ISPB the objects exchanged between communicating entities D socketsC the content in the exchanged messages21.End systems, packet switches, and other pieces of the Internet, run ( )D the location of the hosts that control the sending and receiving of information within the28.In the following options, which does not belong to the network edge?Internet.( )A programsA end systemsB processesB routersC applicationsC clientsD protocolsD servers22.There are many private networks, such as many corporate and29.In the following options, which belongs to the network core? ( ) government networks, whose hosts cannot exchange messages withA end systemshosts outside of the private network. These private networks are oftenB routersreferred to as ( ).C clientsA internetsD serversB LAN30.In the following options, which is not the bundled with the Internet ’s C intranetsconnection-oriented service? ( ) D WANA reliable data transfer23.The internet allows ( ) running on its end systems to exchange dataB guarantee of the transmission timewith each other.C flow control***A clients applicationsD congestion-controlB server applications31.An application can rely on the connection to deliver all of its data C P2P applicationswithout error and in the proper order. The sentence describes ( ).2A flow control C data switchingB congestion-control D message switchingC reliable data transfer 40.In ( ) networks, the resources needed along a path to provide forD connection-oriented service communication between the end system are reserved for the duration 持续of the communication session. 32.It makes sure that neither side of a connection overwhelms 淹没压倒the other side by sending too many packets too fast. The sentence A packet-switcheddescribes ( ). B data-switchedA flow control C circuit-switchedB congestion-control D message-switchedC connection-oriented service 41.In ( ) networks, the resources are not reserve d; a session’s messagesD reliable data transfer use the resources on demand, and as a consequence, may have to wait 33.It helps prevent the Internet from entering a state of gridlock. When a for access to communication link.packet switch becomes congested, its buffers can overflow and packet A packet-switchedloss can occur. The sentence describes ( ). B data-switchedA flow control C circuit-switchedB congestion-control D message-switchedC connection-oriented service 42.In a circuit-switched network, if each link has n circuits, for each linkD reliable data transfer used by the end-to-end connection, the connection gets ( ) of the 34.The Internet’s connection-oriented service has a name, it is ( ). link ’s bandwidth for the duration of the connection.A TCP A a fraction 1/nB UDP B allC TCP/IP C 1/2D IP D n times35.In the following options, which service does not be provided to an 43.For ( ), the transmission rate of a circuit is equal to the frame rate application by TCP?( ) multiplied by the number of bits in a slot.A reliable transport A CDMAB flow control B packet-switched networkC video conferencing C TDMD congestion control D FDM36.The Internet’s connectionless service is called ( ). 44.( ) means that the switch must receive the entire packet before it canA TCP begin to transmit the first bit of the packet onto the outbound link.B UDP A Queuing delayC TCP/IP B Store-and-forward transmissionD IP C Packet loss37.In the following options, which does not use TCP?( ) D PropagationA SMTP 45.The network that forwards packets according to host destinationB internet telephone addresses is called ( ) network.C FTP A circuit-switchedD HTTP B packet-switched38.In the following options, which does not use UDP?( ) C virtual-circuitA Internet phone D datagramB video conferencing 46.The network that forwards packets according to virtual-circuit numbersC streaming multimedia is called ( ) network.D telnet A circuit-switched39.There are two fundamental approaches to building a network core, ( ) B packet-switchedand packet switching. C virtual-circuitA electrical current switching D datagramB circuit switching3。

计算机网络英文题库

计算机网络英文题库

计算机网络英文题库(附答案)c h a p t e r2(总17页) -本页仅作为预览文档封面,使用时请删除本页-Chapter 2 Application Layer1. In the following four descriptions, which one is correctA In C/S architecture, clients communicate with each other directly.B In C/S architecture, client has a fixed well-known address.C In P2P architecture, peers communicate with each other directly.D In P2P architecture, peer has a fixed well-known address.2. In the context of a communication session between a pair of process, the process that initiates the communication is labeled as the , the process that waits to be contacted to begin the session is labeled as the .A client process, server processB sending process, receiving processC input process, output processD communicating process, connecting process3. A socket is the interface between within a host.A the network layer and the link layerB the link layer and the physical layerC the application layer and the transport layerD the transport layer and the network layer4. In the following applications, which one is a loss-tolerant applicationA E-mailB file transferC instant messagingD real-time audio5. In the following applications, which one is a bandwidth-sensitive applicationA E-mailB web applicationC real-time audioD file transfer6. The service of TCP can’t guarantee .A delivery of all data without errorB delivery of all data in the proper orderC the rate of deliveryD congestion control7. In the following applications, which one uses UDPA E-mailB web applicationC file transferD DNS8. In the following descriptions about HTTP, which one is not correctA HTTP uses non-persistent connections in its default mode.B HTTP uses TCP as its underlying transport protocol.C HTTP is a stateless protocol.D HTTP is client-server architecture.9. Suppose a web page consists of a base HTML file, 5 JEPG images and a java applet, and also suppose HTTP uses persistent connection without pipelining, the total response timeis .A 2RTTB 8RTTC 12 RTTD 14RTT10. In HTTP response message, if the requested HTTP protocol version is not supported, the status code is .A 200B 301C 400D 5051~5 CACDC 6~10 CDABD11. The port number of web application is .A 25B 20C 80D 5312. A network entity that satisfies HTTP requests on the behalf of an origin web server is .A server farmB server stackC proxy serverD edge server13. In the following descriptions about persistent connection, which one is not correctA The server leaves the TCP connection open after sending a response.B Each TCP connection is closed after the server sending one object.C There are two versions of persistent connection: without pipelining and with pipelining.D The default mode of HTTP uses persistent connection with pipelining.14. FTP uses two parallel TCP connections to transfer a file, there are .A control connection and data connectionB receiving connection and sending connectionC client connection and sever connectionD program connection and process connection15. In the following descriptions about FTP, which one is correctA FTP is p2p architecture.B FTP sends its control information out-of-band.C FTP uses persistent connection.D FTP is a stateless protocol.16. In the commands of FTP, which one does not have parameterA USERB PASSC LISTD STOR17. The Internet mail system has three components which they are .A user agent, SMTP, POP3B SMTP, POP3, IMAPC user agent, SMTP, IMAPD user agent, SMTP, mail server18. If the status code in HTTP response message is 404, it means .A Request succeeded.B The requested document doesn’t exit on this server.C This is a generic error code indicating that the request could not be understood by the server.D Requested object has been permanently mover.19. Comparison HTTP with SMTP, the correct is .A HTTP is a push protocol, and SMTP is a pull protocol.B In the default mode, both of them use persistent connection.C HTTP place s all of the message’s objects into one message, and SMTP sends every object one by one.D HTTP requires each message to be in 7-bit ASCII format, and SMTP doesn’t impose this restriction.20. The headers in the MIME message must include except .A FromB Content-typeC Content-transfer-encodingD MIME version11~15CCBAB 16~20 DDBBD21. In the following protocol, which one is statelessA POP3B SMTPC FTPD IMAP22. DNS means .A Data Name SystemB Data National SystemC Domain Name SystemD Domain National System23. There are three classes of DNS server except .A Root DNS serverB Local DNS serverC TLD server D Authoritative DNS server24. DNS provides some services except .A Host aliasingB Mail server aliasingC Load distributionD A single point of failure25. There are three architectures for locating content in P2P file sharing, KaZaA uses .A Centralized Directory (Napster)B Query Flooding(Gnutella)C Exploiting Heterogeneity (p141)D Incentive Priorities26. There are three architectures for locating content in P2P file sharing, Napster uses .A Centralized Directory (p137)B Query FloodingC Exploiting HeterogeneityD Incentive Priorities27. The following architectures in P2P file sharing, which is an overlay networkA Centralized DirectoryB Query Flooding(p139)C Exploiting HeterogeneityD Incentive Priorities28. The time it takes for a small packet to travel from client to server and then back to the client is .A round-travel timeB next-hop timeC round-trip timeD prefix-matching time29. Suppose A ( with a Web-based e-mail account ) sends a message to B ( who accesses his mail server using POP3), which application-layer protocol is not usedA HTTPB SMTPC POP3D IMAP30. In the four following options, which protocol is included in Mail Access ProtocolA SMTPB DHCPC IMAPD FTP31. In FTP commands, is used to send user password to the server.A UserB PassC RetrD Stor32. The function of the additional header field in MIME Content-Type is .A to convert the message body to its origin non-ASCII formB to determine what actions it should take on message bodyC to send an E-mail to the receiving user agentD to indicate what type the message is33. In the four following options, which application is organized as hybrid of C/S and P2P architectureA E-mailB OICQC File transferD Web application34. In the four following options, which is not a centralized DNS design’s problemA a single point of failureB traffic volumeC distant centralized databaseD slow (maintenance)35.In the following options, from the application developer’s perspective, which is not correctA the network architecture is fixedB the network architecture provides a specific set of services to applicationsC the application architecture is designed by the physical devicesD the application architecture dictates how the application is organized over the various end systems36. There are three predominant architectures used in modern network applications, which one is not includedA the client-server architectureB the P2P architectureC a hybrid of the client-server and P2P architectureD a hybrid of the client-server and browser-server architecture37. In the following options about C/S architecture, which is not correctA In C/S architecture, there is an always-on host, called the server.B In C/S architecture, there is an always-on host, called the client.C The server has a fixed, well-known address, called IP address.D Clients do not directly communicate with each other.38. are often used to create a powerful virtual server in C/S architecture.A PeersB Server farmC server stackD local server39. A process sends messages into, and receives messages from, the network through its .A socketB programC clientD peer40. Which one is not defined by an application-layer protocolA the types of messages exchangedB the syntax of various message typesC the semantics of the fieldsD rules for determining when and how to translate the socket41. HTTP can use two types of connections, which are .A persistent and non-persistent connectionB connection with pipelining and without pipeliningC TCP and UDPD parallel and serial connection42. takes for a small packet to travel from client to server and then back to the client.A RDTB thresholdC RTTD overhead43. The default mode of HTTP uses .A non-persistent connection with pipeliningB non-persistent connection without pipeliningC persistent connection with pipeliningD persistent connection without pipelining44. In HTTP request messages, the request line has three fields, there are .A the method field, the URL field and the HTTP version fieldB the method, the connection and URL fieldC the user-agent, the method and HTTP version fieldD the user-agent, the URL and the HTTP version field45. In the header lines of HTTP request message, if the field of Connection is close, it specifies .A the host on which object residesB what type of the user agentC that the browser wants the server to close the connection after sending the requested objectD which language can the browser receive46. In HTTP response message, if the status code is 404, it means .A request succeeded and the information is returned in the responseB requested object has been permanently movedC the requested HTTP protocol version is not supported by the serverD the requested document does not exist on this server47. is a network entity that satisfies HTTP requests on the behalf of an origin Web server.A proxy serverB local serverC DNS serverD Web server48. In the following four options about web cache, which one is not correctA A web cache is both a server and a client at the same time.B A web cache is purchased and installed by an ISP.C A web cache can raise the response time for a client request.D A web cache can reduce traffic on an institution’s access link to the Internet.49. The request message in the conditional GET must include the header line.A Last-ModifiedB Last-ReferencedC If-Modified-SinceD If –Referenced-Since50. FTP uses two parallel connections to transfer a file, they are .A TCP and UDP connectionB connection with pipelining and without pipeliningC control an data connectionD client-server and browser-server connection51. In FTP commands, which one is used to ask the server to send back a list of all files in the current remote directoryA USERB PASSC LISTD RETR52. In the Internet mail system, allow users to read, reply to, forward, save and compose message.A User agentsB mail serversC SMTPD TCP53. The two key MIME headers for supporting multimedia are .A Content-Type and MIME-VersionB Content-Type and Content-Transfer-EncodingC Content-Transfer-Encoding and MIME-VersionD MIME-Version and MIME-Type54. For Internet mail, the mail access protocol is used to .A transfer mail from the recipient’s mail server to the recipient’s user agentB transfer mail from the sender’s mail server to the recipient’s mail serverC translate the mail fr om the sender’s mail serverD translate the mail into the recipient’s mail server55. POP3 progresses through three phases, which they are .A authorization, translation and transactionB authorization, translation and updateC authorization, transaction and updateD translation, transaction and update56. In the following four services, which one can not provide by DNSA Host aliasingB Mail server aliasingC translate hostname to IP addressesD translate MAC addresses to IP addresses57. There are three classes of DNS servers, there are .A root DNS server, top-level domain DNS server and local DNS serverB root DNS server, top-level domain DNS server and authoritative DNS serverC root DNS server, local DNS server and authoritative DNS serverD root DNS server, local DNS server and top-level domain DNS server58. In the following four options about POP3, which one is not correctA The user agent employed only three commands: List, Retr and QuitB The server does not carry state information across POP3 sessionsC The port number is 110D The POP3 protocol does not provide any means for a user to create remote folders and assign messages to folders.59. A resource record in DNS distributed database is a four-tuple, which field can be ignored(p132) A Name B Value C Type D TTL 60. In the following four options about DNSresource record, which one is correctA The meaning of Name and Value depend on Type.B The meaning of Value and Type depend on Name.C If Type=A, then Name is a domain and Value is the IP address for the hostname.D If Type=MX, then Name is domain and Value is the IP address for the hostname.61. In the following four options about DNS messages, which one is not correctA There are only two kinds of DNS message.(p133)B Both query and reply message have the same format.C The header section in DNS message has 12 bytes.D The authority section contains the resource records for the same that was originally queri ed.62. In DNS message, contains information about the query that is being made.(p133)A authority sectionB question sectionC answer sectionD additional section63. There are three techniques are employed in most any P2P file-sharing systems, which one is not include (p144)A Request queuingB incentive prioritiesC parallel downloadingD Response queuing64. In the following four options about P2P file-sharing, which one is not correctA P2P file-sharing is highly scalable.B P2P file-sharing relies on P2P architecture.C The means for locating content in different P2P file-sharing are different.D P2P file-sharing systems not only share MP3s,but also videos, software, documents and images.65. In MIME header lines, specifies the name of the SMTP server that sent the message (f rom),the name of the SMTP server that received the message (by), and the time an which the rec eiving server received the message.A ReceivedB FromC ToD MIME-Version66. If the header line Connection is close, it means that the client wants .A persistent connection with pipeliningB persistent connection without pipeliningC nonpersistent connectionD not connection67. In HTTP request message, the entity body is empty with the method, but is used with the method.A GET, POSTB POST,GETC GET, HEAD D POST, HEAD68. In HTTP response message, if the Date: header ;one indicates the time Fri. 08 Aug. 2008 12:00:00 GMT, the Last-Modified: header line can not be .A Fri. 08 Aug. 2008 11:00:00 GMTB Fri. 08 Aug. 2008 11:30:00 GMTC Fri. 08 Aug. 2008 12:00:00 GMTD Fri. 08 Aug. 2008 12:30:00 GMT69. In the following four options, which one is not the part of cookie technologyA Cookie header lines in the HTTP response message and request message.B One cookie header file kept on the user’s end system and managed by the user’s browser.C A network entity that satisfies HTTP requests on the behalf of an origin Web server.D A back-end database at the Web site70. On-top of stateless HTTP, can be used to create a user session layer.A proxy serverB Web cacheC cookieD socket71. Processes communicate with each other by reading from and writing to .A programsB threadsC socketsD channels72. In the following four options about network architecture, which one is not correctA The network architecture is fixed.B The network architecture provides a specific set of services to application.C The network architecture is designed by application developer.D The network architecture dictates how the application is organized over special server.73. In Client-Server architecture, the clients visit the server’s through .A client’s socketB client’s IP addressC server’s socketD server’s IP address74. can be thought of as a program that is running within end system.A processB threadC socketD context75. API means .A Application Program InterfaceB Application Process InterfaceC Appellation Program InterfaceD Appellation Process Interface76. One host can be running many network applications, so the system assigns them differentto distinguish each other.A IP addressB port numberC hostnameD section77. In the following four applications, which one is both bandwith-sensitive and require tight timing constraintsA real-time audioB file transferC E-mailD Web documents78. The port number of the Web server is .A 25B 20C 80D 808079. The port number of the mail server is .A 25B 20C 80D 808080. Look the URL the object’s path name is .A B /rjxy/ D81. Each URL has components, they are .A transport protocol and object’s path nameB host name and object’s path nameC transport protocol and host nameD client name and server name1. Consider an HTTP client will request a WEB page from a WEB server. Suppose the URL of the page is /somedir/. The client does not want to use persistent connections and want to receive French version of the object. The user agent is Windows NT . Give the request message according to the given format.Request line:Header lines:2. Telnet into a Web server and send a multiline request message. Include in the request message the If-modified-since: header line to force a response message with the 304 Not Modified status code.Solution:Request line:Header lines:3. Suppose within you Web browser you click on a link to obtain a Web page. The IP address for the associated URL is not cached in your local host, so a DNS look-up is necessary to obtain the IP address. Suppose that n DNS servers are visited before your host receives the IP address from DNS; the successive visits incur an RTT of RTT1,…,RTT n. Further suppose that the Web page associated with the link contains exactly one object, consisting of a small HTML text. Let RTT0 denote the RTT between the local host and the server containing the object. Assuming zero transmission time of the object, how much time elapses from when the client clicks on the link until the client receives the object5. Suppose that you send an e-mail message whose only data is a microsoft excell attachment. What might the header lines (including MIME lines) look like。

  1. 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
  2. 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
  3. 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。

Computer Network Test Paper1.Who invented IP and some related Internet protocols? Ba)Vinton Cerf and Bob Metcalfeb)Vinton Cerf and Robert Kahnc)Bob Metcalfe and Ivan Sutherlandd)Bob Metcalfe and David Clark2.In the OSI reference model,3.The upper layers of the OSI model are, in correct order Ba)Session, application, presentationb)Session, presentation, applicationc)Session, application, presentation, physicald)Application, presentation, session4.The lower layers of the OSI model are, in correct order Da)physical, system, network, logicalb)physical, logical, network, systemc)physical, transport, network, data linkd)physical, data link, network, transport5.The Internet Protocol (IP) generally corresponds to which OSI layer? Aa)Network (layer three)b)Transport (layer four)c)Data link (layer two)d)Session (layer five)6.MTU stands for Ca)Minimum Transfer Unitb)Minimum Transmission Unitc)Maximum Transmission Unitd)Maximum Transfer Unit7.What layer of the OSI model is designed to perform error detection functions?Ba)Physicalb)Data linkc)Networkd)transport8.Which of these network devices primarily functions at the OSI Network layer(layer 3)? Ca)Switchb)Gatewayc)Routerd)All of the above9.What is the size of today’s standard (IPv4) IP address? Aa) 4 bytes (32 bits)b)12 bytes (96 bits)c)15 bytes (120 bits)d)16 bytes (128 bits)10.What is the size of the next-generation (IPv6) IP address?a) 4 bytes (32 bits)b)12 bytes (96 bits)c)15 bytes (120 bits)d)16 bytes (128 bits)11.Which of the following higher-level protocols runs over IP? Da)FTPb)HTTPc)SMTPd)All of the above12.Which of the following IPv4 addresses is the loopback address? Ca)0.0.0.0b)10.0.0.1c)127.0.0.1d)255.255.255.25513.Which of the following IPv6 addresses is the loopback address? Ba)0::0b)0::1c)127::0d)127::114.The length of an IP datagram header can vary depending on the options used. Whatis the smallest possible IP header size? Ba)16 bytesb)20 bytesc)24 bytesd)60 bytes15.The source IP address for an IPv4 datagram is stored where in the header?Ca)2nd longword (bytes 5-8)b)3rd longword (bytes 9-12)c)4rd longword (bytes 13-16)d)5rd longword (bytes 17-20)16.The destination IP address for an IPv4 datagram is stored where in the header?Da)2nd longword (bytes 5-8)b)3rd longword (bytes 9-12)c)4rd longword (bytes 13-16)d)5rd longword (bytes 17-20)17.The header length field in an IPv4 datagram contains the size of an IP headermeasured in number of Ca)Bitsb)Bytesc)Longwords (4 bytes)d)None of the above18.Can IP run over any other physical networks besides Ethernet? Da)No (and IP does not run over Ethernet)b)Noc)Yes (but IP does not run over Ethernet)d)Yes19.What function does Address Resolution Protocol (ARP) perform? Aa)Converts IP addresses to Ethernet addressesb)Automatically assigns IP addresses to computersc)Prevents two computers from using the same IP addressd)None of the above20.What mechanism does ARP use to resolve IP addresses? Ba)Mathematical formulab)Lookup tablec)Central web sited)Random number generator21.Which utility program is designed to report whether a networked computer isresponding at a given IP address, and how long these responses take? Ba)tracerouteb)pingc)ttcpd)netstate22.which of these shell commands supplies the IP address of a computer running theLinux operating system? Ba)ipconfigb)ifconfigc)linuxconfd)none of the above23.Which of the following technologies manage the conversion between IP addressesand host names? Ba)BGPb)DNSc)ARPd)All of the above24.CIDR stands for Da)Class-based Internet Domain Routingb)Careful Inter-Domain Routingc)Constant Internet Domain Routingd)Classless Inter-Domain Routing25.In CIDR notation, which of the following networks contains host 192.168.14.2?Ba)192.168.10.0/22b)192.168.11.0/21c)192.168.12.0/23d)192.168.13.0/2426.Which central authority is responsible for allocating IP addresses on theInternet? Ba)IETFb)IANAc)IEEEd)None of the above27.The IP delivery service is Ca)Reliable, connection-orientedb)Non-routablec)Unreliable, connectionlessd)None of the above28.TCP stands for Aa)Transmission Control Protocolb)Trivial Connection Protocolc)Traffic Control Protocold)Telephony Connection Protocol29.UDP stands for Ca)Universal Data Protocolb)Unreliable Datagram Protocolc)User Datagram Protocold)Ultimate Data Protocol30.Both TCP and UDP belong to which layer of the OSI mode? Ba)Sessionb)Transportc)Networkd)Data Link31.UDP offers which of the following benefits relative to TCP? Aa)UDP consumes fewer computer resources by not maintaining connection stateb)UDP supports a self-regulating “throttle” feature that prevents networksaturationc)UDP guarantees that Individual packets of a transmission will arrive “inorder”d)None of the above32.What is the maximum recommended length of twisted-pair Ethernet cables used inhome or business networks? Ba)10 metersb)100 metersc)1000 metersd)Other33.On Ethernet LANs, the Ethernet address is also known as the Ba)IP addressb)MAC addressc)Virtual addressd)Other34.How long is a MAC address? Ba) 4 bytesb) 6 bytesc)8 bytesd)10 bytes35.What is the basic unit of Ethernet traffic? Ba)Fileb)Framec)Packetd)Stream36.CSMA/CD stands for Aa)Carrier Sense Multiple Access with Collision Detectionb)Collision Sense Multiple Access with Carrier Detectionc)Carrier Single-Multiple Access with Collision Detectiond)Collision Single-Multiple Access with Carrier Detection37.Which of the following is a routing protocol?a)ARPb)DNSc)BGPd)SMTP38.Which of the following algorithm has the so called count-to-infinity problem?Ca)Flooding algorithmb)Link-state algorithmc)Distance vector algorithmd)None of the above39.Which of the following algorithm does BGP use? Ca)Flooding algorithmb)Link-state algorithmc)Distance vector algorithmd)None of the above40.Which of the following protocol does ICMP run over? Ca)TCPb)UDPc)IPd)Ethernet41.Which of the following describes the TCP connection establishing mechanism?Ca)One-way-handshakeb)Two-way-handshakec)Three-way-handshaked)Four-way-handshake。

相关文档
最新文档