iSCSI Gets Go-Ahead

The Internet Engineering Task Force (IETF) late yesterday officially approved the iSCSI specification as a "proposed standard" -- a much-anticipated procedural step that should finally kick IP SANs into forward motion.

The seal of approval by the IETF's Internet Engineering Steering Group (IESG) -- which is responsible for technical management of the Internet standards process -- comes just over three years after Cisco Systems Inc. (Nasdaq: CSCO) and IBM Corp. (NYSE: IBM) first submitted the basic framework for the block-level IP storage protocol in January 2000.

The iSCSI protocol, in the IETF's somewhat baroque description, "describes a means of transporting of the SCSI packets over TCP/IP, providing for an interoperable solution which can take advantage of existing Internet infrastructure." Essentially, iSCSI is designed to provide congestion control and security features not provided for in the core TCP/IP stack.

Analysts say the IETF's ratification knocks down the last major hurdle for iSCSI to become widely supported.

"Now that it's done, Microsoft Corp. [Nasdaq: MSFT] and Novell Inc. [Nasdaq: NOVL] will release drivers, and the games will begin," says Steve Duplessie, senior analyst at Enterprise Storage Group Inc. "Anyone who doesn't think this is the beginning of a huge market is insane."Microsoft has said it will provide iSCSI compatibility for Windows 2000, Windows XP, and Windows Server 2003 within 90 days of the specification's ratification. The official approval of iSCSI is guaranteed to give fresh energy to numerous startups and large companies alike that are developing storage arrays, adapters, TCP-acceleration chips, and software for IP SANs (see IP Storage Has a Pulse, HP Takes iSCSI Baby Step, and iSCSI's Big Bang?).

However, there was about a five-month delay after the IETF's IP Storage Working Group had finished the bulk of its technical work on iSCSI and the IESG's official OK -- which caused the momentum behind iSCSI to slow (see iSCSI Spec Set).

What happened? Duplessie says politics always rears its ugly head when it comes to setting standards. "At first they all worked together beautifully, learning a lesson from the Fibre Channel fiasco," he says, referring to the major interoperability problems that plagued FC in its early years. "But once all the hard work was done [on iSCSI], the posturing began."

But David Black, senior technologist at EMC Corp. (NYSE: EMC) who is co-chair of the IETF's IP Storage Working Group, says the time the iSCSI draft -- a 238-page document -- spent with the IESG wasn't unusual.

"In terms of amount of text changes, it was very minor," he says. "There are people who are champing at the bit to make major protocol changes, but I've said we are going to make no major changes for at least the next year. People need to get some air time and maturity before we start tinkering."There was one notable technical change to iSCSI required by the IESG, in the way that it used the Challenge Handshake Authentication Protocol (CHAP). "Some nasty reflection attacks were discovered on iSCSI's use of CHAP when the same secret is used in both directions of a bidirectional authentication," Black says. "Hence, the use of the same secret in both directions had to be prohibited -- separate secrets must be used in each direction, and this condition must be checked. This took a bit longer to unscramble than I originally expected."

But aside from that, the IETF made only a few minor editorial modifications to the iSCSI spec between the IP Storage Working Group's approval of iSCSI (when it was at draft 16) and the version it ratified (draft 20).

The protocol was reviewed for the IESG by EMC's Black, Allison Mankin of the University of Southern California's Information Sciences Institute (ISI); Elizabeth Rodriguez of Brocade Communications Systems Inc. (Nasdaq: BRCD); and Bernard Aboba of Microsoft Corp. (Nasdaq: MSFT).

The full text of the iSCSI draft 20 specification is available at http://www.ietf.org/internet-drafts/draft-ietf-ips-iscsi-20.txt.

Todd Spangler, US Editor, Byte and SwitchWhat was holding iSCSI back? To vote in this month's poll, click here