Vendors Propose Fibre Channel Over Ethernet Standard

Published: April 19, 2007

by Timothy Prickett Morgan

I don't recall who said it first, but I know it wasn't me as much as I know it to be absolutely true: Any protocol that comes up against Ethernet eventually loses. It was probably Bob Metcalf, the creator of Ethernet and the founder of 3Com. Fibre Channel is feeling the burn indirectly from iSCSI, and rather than take on Ethernet directly, its proponents have now come up with a truce: Run Fibre Channel protocols over Ethernet.

Ethernet, which was conceived back in 1973 by Metcalf, is an amazingly resilient technology. Token Ring, IBM's network topology and electronics that it married to Systems Network Architecture software, came up against Ethernet and the TCP/IP protocol directly, and after a gigantic struggle that culminated in the Internet, Token Ring was banished to oblivion. So were Asynchronous Transfer Mode (ATM) and Integrated Services Digital Network (ISDN), earlier high-speed protocols for network backbones, once Ethernet caught up in the bandwidth race. InfiniBand was supposed to beat Ethernet and become the standard for linking systems to each other and to storage in a switched fabric; that sure didn't happen, although InfiniBand does have some good niche uses in high performance supercomputing and in database clustering (but, alas, not for long if history is any guide). The SCSI protocol and wiring that is used to link peripherals to machines has been extended to work over Ethernet links with iSCSI, and as Ethernet networks go from Gigabit Ethernet (GE) to 10 Gigabit (10GE), 40 Gigabit (40GE), and even 100 Gigabit (100GE) links, it is clear that this simple and relatively inexpensive way of linking to external storage (thanks to the ubiquity of Ethernet hardware) is going to take off. And that, perhaps, is why the people behind the Fibre Channel protocol, which is used to link servers to storage area networks, are now talking about extending the Fibre Channel protocol so it can run over Ethernet. Better to embrace Ethernet than to face being banished to oblivion by iSCSI.

A group of storage vendors, including Brocade, Cisco Systems, EMC, Emulex, IBM, Intel, Nuova, QLogic, and Sun Microsystems, have put together a technology specification proposal that they have submitted to the American National Standards Institute to create a standard called Fibre Channel over Ethernet, or FCoE.

With FCoE, customers who have made a big investment in Fibre Channel SAN storage gear would be able to link them back to servers using Ethernet cabling rather than Fibre Channel light pipes, which are more expensive. The Fibre Channel protocols are widely recognized as being more resilient than iSCSI, and have a lot of sophisticated features for data multipathing and error scrubbing.

Once again, a technology is being heralded as the unifying data center fabric. Maybe this time, because we are talking about Ethernet, it will actually happen.

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