第六章《网络通信》 计算机专业英语

append[ə‘pend] 附上 Impose [im‘pəuz] 强加 duration[djuə’reiʃən] 持续时间
Unit 6 Network Communication 6.X Gigabit Ethernet: From 100 to 1000 Mbps
An optional frame bursting feature was defined to improve the throughput of gigabit CSMA/CD LANs. Frame bursting allows multiple short packets to be transmitted consecutively, up to limit, without relinquishing control of the signaling channel and reverting to the CSMA/CD protocol between packets. Thus, it offers a way to avoid the overhead associated with the carrier extension technique for all but the first packet of a burst.
Unit 6 Network Communication 6.X Gigabit Ethernet: From 100 to 1000 Mpbs
In this tutorial, we describe the operation of Gigabit Ethernet over fiber-optic cabling and the emerging IEEE standards project known as 1000Base-T, which addresses operation over Category-5 UTP cabling. Layers of Change Any tutorial concerning a network interface and access protocol standard must refer first to the ISO seven-layer reference model. Like most specifications produced by the IEEE 802 LAN/MAN standards committee, Gigabit Ethernet (IEEE802.3z) addresses the two lowest layers of the model.
计算机专业英语
第七讲 网络通信
倪胜 广西医科大学 计算机网络应用教研室
Unit 6 Network Communication 6.X Gigabit Ethernet: From 100 to 1000 Mpbs
The installed base for Ethernet ranges form PCs and servers to printers, test equipment, telephone switches, cable TV set-top boxes, process control systems, and even high-end theatrical lighting systems. In short, Ethernet is ubiquitous—which is to say, consumers can’t get enough of it. The great value of Ethernet is not that one size fits all, but that common protocols and models are available at a wide range of price/performance points. Originally standardized and deployed at 10 megabits per second,
Unit 6 Network Communication 6.X Gigabit Ethernet: From 100 to 1000 Mbps
The carrier extension appends a set of special symbols to the end of short frames so that the resulting transmission is at least 4096 bit-times in duration(4096 microseconds), up form the minimum 512 bit-times imposed at 10 and 100Mbps. 载波拓展功能在短帧的后尾附上一组特定的符号， 使得传输时间至少是4096比特时间（4096毫秒），比 强制在10和100Mbps以太网下的512比特最小时间要高。
context 背景；上下文
Unit 6 Network Communication 6.X 1000 Mpbs
Carrier Sense Multiple Access with Collision Detection = CSMA/CD 抗碰撞的载波监听多址访问协议 MA = multiple access protocol 多址访问协议 CSMA = carrier sense multiple access 载波监听… The CSMA/CD protocol coordinates data transmission within Ethernet’s share-access physical bus topology. It enables each computer to sense the coaxial cable for electrical carrier signals before a frame is sent(CSMA) and to detect the simultaneous transmission of data(CD). Share-Access Topology Enhancements. The Gigabit Ethernet standard includes CSMA/CD with two important modifications.
scale up 按比例增大；尺度增大 magnitude *‘mæ ɡnitju:d] 重要性；量 underlying[,ʌndə’laiiŋ] 基础的；潜在的 Underlie [,ʌndə‘lai] 位于…之下；构成…的基础 cabling 布线 coaxial [kəu‘æksəl] 同轴
ubiquitous [ju:‘bɪkwɪtəs] 无处不在的 set-top box 机顶盒 high-end theatrical lighting systems 高档的剧场照明系统 theatrical [θi:‘ætrɪkəl] 剧场的；戏剧化的 deploy[di’plɔi] 展开；部署
overcome 战胜 inherent [in‘hiərənt] 固有的 algorithm *’æ lɡəriðəm] 算法 mandate*‘mæ n,deɪt] 授权 round-trip 往返 propagation [,prɔpə’geɪʃən] 传播；繁殖 exceed [ik‘si:d] （数量上）超过
IEEE = Institute of Electrical and Electronics Engineers 电气和电子工程协会 EI = Engineering Index 工程索引 SCI = Science Citation Index 科学引文索引 ISTP = Index to Scientific & Technical Proceedings 科技会议索引 tutorial [tu:‘tɔ:ri:əl,] 教程； emerging 新兴的 address 处理 Specification 详述；规格
Unit 6 Network Communication 6.X Gigabit Ethernet: From 100 to 1000 Mpbs
Layer 2 , the Data-link layer, which describes how data are organized into frames and sent over the network, and Layer 1, the Physical layer, which describes the network medium and signaling specifications. Figure 6-3 represents the elements of the Gigabit Ethernet standard as sublayers in this context. Media Access Layer The Media Access Control sublayer occupies the lower half of the ISO Data-link layer. The MAC sublayer defines the Carrier Sense Multiple Access with Collision Detection protocol, which made Ethernet famous.
coordinate[kəu‘ɔ:dineit] 使协调 simultaneous [,siməl’teinjəs] 同时发生
Unit 6 Network Communication 6.X Gigabit Ethernet: From 100 to 1000 Mbps
A carrier extension was added overcome an inherent limitation of the CSMA/CD algorithm that mandated the round-trip signal propagation delay between two stations not to exceed the time required to transmit the smallest allowable frame. 一种载波拓展功能被添加来克服CSMA/CD的内在限 制，那就是授权两个点之间的往返信号的传播延迟不 超过传输最小允许帧的传输时间。