SAN vendors joust over future of Fibre Channel

SAN JOSE - "Fibre Channel is dead." That was the controversial conclusion of one participant in a heated debate about storage-area networks over Gigabit Ethernet held at the SAN 2000 conference here last week.

Network infrastructure and storage vendors 3Com, Hewlett-Packard, Adaptec, Qlogic, Gadzoox Networks, SAN, Ltd., Network Appliance, Agilent Technologies and Genroco argued over new proposals to carry storage data over 10-Gigabit Ethernet, and what some see as a sooner-rather-than-later demise of Fibre Channel technology.

Four proposals touting storage over IP are currently being submitted to the Internet Engineering Task Force (IETF) for consideration as standards. Included are three that want to send block-mode storage data over 10-Gigabit Ethernet.

There's the SCSI over TCP/IP proposal from IBM and Cisco, which is supported by HP.

There's also a draft specification from Adaptec that calls for a new transport protocol, EtherStorage, in which storage travels over existing Ethernet technology.

And there's SAN, Ltd.'s proposal, the Service Specific Connection Oriented Protocol (SSCOP), to route storage data over IP using an International Telecommunication Union protocol that allows data to be retransmitted selectively if problems occur. SSCOP is a data link protocol used in ATM.

The fourth proposal suggests using IP as a more immediate fix for routing data between geographically separated SANs. It includes work from Gadzoox and Lucent that proposes sticking a metropolitan-area network (MAN) between SANs and routing data between them with devices such as Cisco's Metro 1500 dense wave division multiplexer.

While participants agreed that one specification would eventually prevail and become a standard in an IETF working group, tempers flared as vendors debated the merit of each technology. The panel, a mix of Fibre Channel manufacturers and 10-Gigabit Ethernet proponents, agreed in large part that users are feeling pain implementing Fibre Channel.

"People are very Ethernet-centric in the midsize enterprise, where Ethernet is pervasive," says Mark Lohmeyer, marketing and business development manager for Adaptec. They are not familiar with Fibre Channel installation and interoperability, and have hesitated to adopt it, he adds.

"Fibre Channel is not very good for long distances," adds Wayne Rickard, chief technology officer at Gadzoox, noting the technology's latency, dropped packets and congestion problems. IP-based MANs are a perfect device for joining SANs over distance, Gadzoox says.

Like many of the debate participants, 3Com system architect Dave Lee believes Fibre Channel will not disappear overnight but that its use will wane over the next two years. "The pending drafts [for storage over IP] are not perfect solutions, but they will come to fruition," he says.

Nigel Squibb, technical director for SAN, Ltd. in the U.K., says his company is firmly committed to 10-Gigabit Ethernet. "Remember FDDI? Fibre Channel is just FDDI on steroids," he says. "We are deluding each other if we think anything other than storage over IP will work. Cisco says use IP, and look at what they did to FDDI - they are capable of doing the same to Fibre Channel."

Vendors such as SAN, Ltd., Gadzoox and Adaptec are going ahead with work on storage-over-IP products before a standard is adopted. They say that however those implementations work, they will be software-upgradable when a standard appears.

By year-end, the IETF will have a working demonstration of a storage-over-IP standard.