2Converged Enhanced Ethernet Administrator’s Guide
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FCoE overview
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DRAFT: BROCADE CONFIDENTIAL
FCoE provides a method of encapsulating the Fibre Channel (FC) traffic over a physical Ethernet
link. FCoE frames use a unique EtherType that enables FCoE traffic and standard Ethernet traffic to
be carried on the same link. FC frames are encapsulated in an Ethernet frame and sent from one
FCoE-aware device across an Ethernet network to a second FCoE-aware device. The FCoE-aware
devices may be FCoE end nodes (ENodes) such as servers, storage arrays, or tape drives on one
end and FCoE Forwarders on the other end. FCoE Forwarders (FCFs) are switches providing FC
fabric services and FCoE-to-FC bridging.
The motivation behind using CEE networks as a transport mechanism for FC arises from the desire
to simplify host protocol stacks and consolidate network interfaces in data center environments. FC
standards allow for building highly reliable, high-performance fabrics for shared storage, and these
characteristics are what CEE brings to data centers. Therefore, it is logical to consider transporting
FC protocols over a reliable CEE network in such a way that it is completely transparent to the
applications. The underlying CEE fabric is highly reliable and high performing, the same as the FC
SAN.
In FCoE, ENodes discover FCFs and initialize the FCoE connection through the FCoE Initialization
Protocol (FIP). The FIP has a separate EtherType from FCoE. The FIP includes a discovery phase in
which ENodes solicit FCFs, and FCFs respond to the solicitations with advertisements of their own.
At this point, the ENodes know enough about the FCFs to log into them. The fabric login and fabric
discovery (FLOGI/FDISC) for VN-to-VF port connections is also part of the FIP.
NOTE
With pre-FIP implementations, as an alternative to FIP, directly connected devices can send an
FCoE-encapsulated FLOGI to the connected FCF.
FCoE hardware
At a fundamental level, FCoE is designed to enable the transport of storage and networking traffic
over the same physical link. Utilizing this technology, the Brocade 8000 switch and the Brocade
FCOE10-24 port blade provide a unique platform that connects servers to both LAN and SAN
environments.
Within this manual, any appearance of the term “Brocade FCoE hardware” is referring to the
following hardware:
•Brocade 8000 switch
•Brocade FCOE10-24 port blade
NOTE
The intermediate switching devices in the CEE network do not have to be FCoE-aware. They simply
route the FCoE traffic to the FCoE device based on the Ethernet destination address in the FCoE
frame.