FCOE技术详解

FCoE itself
Is the data plane protocol
It is used to carry most of the FC frames and all the SCSI traffic
FIP (FCoE Initialization Protocol)
It is the control plane protocol
in FC-BB-5
Same Management and Security Models
Completely based on the FC model
Same host-to-switch and switch-to-switch behavior of FC
E.g., in order delivery or FSPF load balancing
1, 10 . . . Gbps
FCOE BENEFITS
FCoE benefits are the same of any I/O consolidation solution
▪Fewer Cables
▪ Both block I/O & Ethernet traffic co-exist on same cable
THE MAPPED MAC ADDRESSES
A dedicated MAC address for each FC-ID
▪Assigned by the FC fabrics ▪ Consistent with the FC model ▪OUIs with U/L = 1 (Local addressing), called FC-MAPs ▪Multiple FC-MAPs may be supported (one per FC fabric)FC fab源自icFCoE mapper
stateless encaps/decaps
FC Target
Stateful gateway issues:
▪Single point of failure ▪Limited scalability
PROTOCOL ORGANIZATION
FCoE is really two different protocols:
FC
port
FCoE Switch
FC
FCF
port
FCoE
FC
port
Ethernet Bridge
FC
port
Eth
Eth
Eth
Eth
Eth
Eth
Eth
Eth
port
port
port
port
port
port
port
port
FC-BB-5 TERMINOLOGY
Unchanged from previous FC standard
Storage IPC LAN
Hosts
Storage devices
I/O CONSOLIDATION IN THE HOST
Fewer CNAs (Converged Network Adapters) instead of NICs, HBAs and HCAs
Less power consumption
▪Requires independent resources per priority (buffers)
High level of industry support
▪Cisco distributed proposal ▪Standard Track in IEEE 802.1Qbb
16
31
Ethertype = IEEE 802.1Q Priority CFI
▪Fewer adapters needed ▪Overall less power
Plus additional advantages of being FC
▪Seamless integration with existing FC SANs ▪No Gateway
FCOE BENEFITS
▪SPMA (Server Provided MAC Addresses) ▪FPMA (Fabric Provided MAC Addresses)
MAC Addresses are negotiated in FIP Initial deployment will use FPMA only
▪aka CNA (Converged Network Adapter)
FC Node
FCoE
FCoE
Enet port
Enet port
FCOE SWITCH: SIMPLIFIED MODEL
FCF (Fibre Channel Forwarder), the forwarding entity inside an FCoE switch
I/O CONSOLIDATION REQUIREMENTS
Ethernet based
▪Lot of investment in data centers
More bandwidth
▪To consolidate existing interfaces ▪PCI Express solves the bandwidth bottleneck in server buses to support 10G interfaces
FCOE: INITIAL DEPLOYMENT
FCOE: ADDING BLADE SERVERS
FCOE: ADDING NATIVE FCOE STORAGE
FCOE: ADDING VE_PORTS
FCOE ADDRESSING AND FORWARDING
FCoE frames have:
▪IEEE 802.1Q defines 8 priorities ▪Traffic classes are mapped to different priorities:
▪ no traffic interference ▪Storage traffic may be paused while IP traffic is being forwarded ▪Or, vice versa
WWNs, FC-IDs, hard/soft zoning, DNS, RSCN
iSCSI Initiator
FCoE Initiator
GATEWAY-LESS FCOE
iSCSI session
Ethernet
FCP session
stateful
iSCSI gateway
FCP session
▪MAC addresses (hop-by-hop) ▪FC addresses (end-to-end)
FCOE MAC ADDRESSES
VE_Ports and VF_Ports always use MAC addresses derived from the switch pool
VN_Ports may use two types of MAC addresses:
Lossless Ethernet allows a direct mapping of Fibre Channel over Ethernet (FCoE)
PRIORITY-BASED FLOW CONTROL (PFC)
Also called Per-Priority Pause (PPP) PAUSE functionality per Ethernet priority
It is used to discover the FC entities connected to an Ethernet cloud
It is also used to login to and logout from the FC fabric
The two protocols have:
FCOE IS FIBRE CHANNEL
FCoE is Fibre Channel at the host and switch level
Easy to Understand
Same
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FCOE PROTOCOL STACK
From a Fibre Channel standpoint it’s FC connectivity over a new type of cable called an Ethernet cloud
From an Ethernet standpoints it’s yet another ULP (Upper Layer Protocol) to be transported
electric interface
10GE SFP+
LOSSLESS ETHERNET
Ethernet may be extended to become lossless:
▪Collisions do not exist in full duplex links ▪ The only ones deployed in data centers ▪Link errors are rare in data centers ▪ They are present also in native Fibre Channel ▪Congestion can be dealt with extensions ▪ Pause-based Flow Control Priority-based Flow Control
▪VN_Port: Virtual N_Port ▪VF_Port: Virtual F_Port ▪VE_Port: Virtual E_Port
Added to support FCoE
▪FCoE_LEP (FCoE Link Endpoint): The data forwarding component that handles FC frame encapsulation/decapsulation, and transmission/reception of FCoE frames. ▪FCoE Controller: the entity that implement the FIP protocol
• Two different Ethertypes • Two different frame formats
FCOE FRAME SIZE
FCOE FRAME FORMAT
ENODE: SIMPLIFIED MODEL
ENode(FCoE Node): a Fibre Channel HBA implemented within an Ethernet NIC
CURRENT DATA CENTER STRUCTURE
Storage devices
Hosts
CONSOLIDATED DATA CENTER STRUCTURE
Storage IPC LAN
Storage devices
Hosts
PRAGMATIC CONSOLIDATED DATA CENTER STRUCTURE
10GE is the best candidate for I/O consolidation
▪High bandwidth ▪Full duplex links ▪Competitive cost ▪ Optical interface cost dramatically reduced by SFP+ modules ▪ Twinax cable in alternative to Cat5e/6/6a cables as low cost
IEEE 802.1Q tag
12 bits
VLAN ID
PRIORITY-BASED FLOW CONTROL
FCOE: FC OVER ETHERNET
FCoE is I/O consolidation of FC storage traffic over Ethernet
▪FC traffic shares Ethernet links with other traffics ▪Requires a lossless Ethernet fabric