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Switch Interoperability Brings Fibre Channel Forward.

Although interoperability has countless definitions in the IT connectivity space, the interoperability that has limited the appeal of Fibre Channel technology and slowed SAN acceptance is switch interoperability. Up until recently, the major switch manufacturers, including Brocade, Vixel, Gadzoox, Ancor, and McData, have not been able to link to one another.

Yet this serious impediment may become a part of storage history with a recent announcement from Brocade. The company's routing protocol, Fabric Shortest Path First (FSPF), has been accepted by the T11 technical committee of the National Committee for Information Technology Standards (NCITS) for approval as an industry standard by the American National Standards Institute (ANSI), the nation's primary Fibre Channel standards body.

FSPF, proposed to T11 by Brocade earlier this year, specifies a common method for routing and moving data among Fibre Channel switches, which provide a networking foundation for Storage Area Networks (SANs). Once ratified by ANSI, the FSPF protocol will be available for implementation by all vendors and will enable any FSPF-compliant switch to interoperate with other FSPF-compliant switches, regardless of the manufacturer. The matter goes to letter ballot in August.

In a prepared statement, Brocade's Jack Cuthbert indicated: "The acceptance of FSPF by the T11 technical committee is another milestone in our continued efforts to further Fibre Channel standards development and facilitate end to end interoperability for Storage Area Networks."

An End To Interoperability Debates?

The acceptance of FSPF could well close major objections to adopting Fibre Channel. Although Fibre Channel solutions are running about $800 per port, according to IDC, cost has only been one of the points of hesitation. Resistance to vendor lock-in has also been a factor, highlighted by the new interest in Fibre Channel alternatives such as IP and Ethernet. Switch interoperability was a fundamental consideration; hub-to-hub interoperability has long been solid, as has fabric-to-arbitrated loop.

Although the routing protocol was generated by Brocade, switch interoperability has been a labor on the part of all switch manufacturers. Brian Reed at Vixel notes that, about a year ago, the switch vendors started their own independent efforts to bring interoperability to FC switching. Some of these efforts showed forth at last May's Networld+Interop show, where four of the vendors--Vixel, Gadzoox, McData, and Ancor--gave a practical demonstration of switch interoperability. The demonstration was based on an ancestor of FSPF, known as OSPF, which some observers indicate provides about 90% of FSPF's functionality. Brocade, reportedly not a party to the joint demonstration, submitted FSPF the month after the show.

The actual submission included more than routing. The offering to T11 includes proposals for link initialization and selection, distribution of name/server, distribution of change state (zoning), and the routing protocol.

The nagging question in the process is: "What took so long?" Sources report that not everyone agreed that interoperability was an issue on which to compete. Vixel's Reed noted that the T11 submission means, in part, "that the industry does recognize that we don't have to compete on interoperability."

Shopping For Standards

Much speculation has surrounded the issue of wholehearted commitment to standards on the part of FC switch market leader Brocade. The company was significant in its absence in the N+I demonstration. The record is clear that the company has been present in SAN standards development since the company was founded in 1995 and has made numerous technology and research contributions to standards groups such as ANSI and the IETF. The company has been involved in various standards activities from data movement and device interoperability to methods for SAN component discovery and management. Brocade's published announcement identified Kumar Malavalli, the company's co-founder and vice president of technology, as serving concurrently on three standards boards. Malavalli chairs the NCITS T11 committee and is a member of the board of the Storage Networking Industry Association (SNIA) and the Fibre Channel Industry Association (FCIA), which promotes Fibre Channel technologies and related products.

Yet it is debatable whether the SNIA or FCIA can be considered standards bodies. SNIA is definitely active in the interoperability area with its own working group in the area, but some observers suggest that SNIA is not organized to set standards. It shows compliance with standards. Such a view is supported by the development of an interoperability lab in Arizona. Very soon, SNIA will be in a position to objectively test and assess interoperabiity of SAN components. This lab is seen as a welcome alternative to vendor interoperability labs that are typically vendor-centric. Imation is, likewise, developing an objective interoperability lab in its Minnesota headquarters.

FCIA is, likewise, actively involved in interoperability issues and supports its own interoperability working group, but the organization is more promotional in its goals, reminiscent of the RAID Advisory Board and FCIA's two constituent founders: the Fibre Channel Association and the Fibre Channel Loop Community. FCIA has developed some hardware SAN benchmarks, but has, at press time, no test for software standards compatibility.


Another anticipated fallout of the standard is the death of the usual dosages of infighting and flag-bearing among switch manufacturers and SAN manufacturers in an effort to steer the future of SAN to each vendor's own lagoon. The infighting done, the next step will be to justify the Fibre Channel investment in the face of competing IP and Ethernet options.

The integrator and VAR are winners in this contest, too. At one time, the focus was on integrated Fibre Channel solutions with vendor lock-in, as far as switches are concerned. Now, the integrator will be able to mix and match best-of-breed solutions and, perhaps, preserve investments in a client's IT infrastructure.

The belief that switch manufacturers could avoid competition and evaluation on the basis of interoperability was pure fantasy. Budgets being what they are in the IT universe, coupled with the crippling shortage of trained IT personnel, the ability to mix and match solutions based on application, budget, and availability has always been in the cards. Yet, with any kind of good luck, the issue will be settled by ANSI vote.
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Title Annotation:Technology Information
Author:Ferelli, Mark
Publication:Computer Technology Review
Date:Jul 1, 2000
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