Storage-Over-IP to Emerge in 2001

That's right—this year is the year that storage-over-IP emerges as a serious storage networking protocol. The big question is—which protocol will emerge as the standard? You might be having trouble keeping track of the different proposals, the players associated with each, and the proposals' prospects. However, the principle driving forces that will make storage-over-IP a reality are multi-Gigabit Ethernet (GigE) standards and network architects' need to leverage their current network infrastructure to move data in and out of storage.

Let's consider four of the current proposals for IP storage networking. Perhaps the best known is SCSI over IP (iSCSI), which is now in draft format with the Internet Engineering Task Force (IETF). Fibre channel standards include Fibre Channel over IP (FCIP) and Fibre Channel Backbone. The IETF and the ANSI committees are considering FCIP, and ANSI is considering Fibre Channel Backbone. The fourth proposed standard is Storage over IP (SoIP), a superset of iSCSI and FCIP.

I think iSCSI might have a reasonable chance to establish itself in small networks and on departmental networks in the next year, even though the current standard lacks SNMP MIB support, IP Security (IP Sec), asynchronous transfer mode (ATM) transport protocol, and the SCSI Encapsulation Protocol (SEP). These features could be added later.

Adaptec, Cisco, Hewlett-Packard (HP), IBM, Quantum, and SANgate support this new standard. iSCSI transports block data over Ethernet cable using current networking standards and equipment. iSCSI works with standard networking hubs and requires only new host bus adapters. iSCSI will be attractive for hubs with GigE ports, and it can work with fibre channel storage devices using a fibre channel-to-GigE router. We should see the IETF adopt an iSCSI standard this year and by year's end see Adaptec and Cisco ship first-generation iSCSI products.

FCIP works by encapsulating IP frames or transport over GigE, Synchronous Optical Ethernet (SONET) or ATM, WAN, or metropolitan area networks (MANs). Brocade, Gadzoox, Lucent, McData, and Qlogix support FCIP. FCIP is particularly attractive for connecting geographically separated Storage Area Networks (SANs), letting vendors leverage existing IP infrastructure without having to change existing equipment. You can buy FCIP solutions today, before the standard is ratified, and apparently you will be able to use software to upgrade the equipment to the standard. Entrada Networks is already shipping a multiprotocol router, which I covered in the January 8, 2001, issue of Storage UPDATE.

Brocade and Gadzoox, two of the major fibre channel switch vendors behind FCIP, are also behind the Fibre Channel Backbone proposal that ANSI is now considering. In this scenario, fibre channel between switches provides a longer transmission distance and higher throughput than FCIP alone.

Nishan Systems, a startup with venture capital from Dell, Quantum, Siemens, and Sun Microsystems, proposed the SoIP standard. Nishan's standard is inclusive, which offers an attractive eventual resting place for all of the competing standards. Cisco is emerging as a storage infrastructure contender, and—given the company's market clout—Cisco's support of SoIP could help make this technology credible. However, given the potential money that could change hands in this marketplace and the fact that technical people from each of the storage industry's major companies populate the standards bodies, it's unlikely that Nishan's standard will emerge as the single unifying standard for IP storage networking—but it could happen. SoIP might establish itself if multiple proposed standards garner enough support to be adopted. For example, if a company puts iSCSI into its network for local storage and FCIP for longer distances and more complex storage device connections, the company must support multiple standards—and might find SoIP attractive to tie it all together.

One organization that hopes to play a prominent role in IP storage networks is the Storage Networking Industry Association (SNIA). When SNIA started out, it wasn't entirely clear whether Compaq would dominate the organization. But SNIA is becoming a broad industry forum for standards adoption, with strong support from all industry leaders. As an example, consider EMC and Sun's recent announcement that they want SNIA to endorse a mechanism for Network File Systems (NFS) and Common Internet File Systems (CIFS) to communicate over a Virtual Interface (VI) interface. (EMC's work on its new HighRoad product is behind the standard.)

If you want to receive many detailed technology letters, you can sign up for the SNIA reflector. To sign up, email [email protected], and ask to be put on the reflector. You'll see how important SNIA considers IP storage networking to be and learn about some of the issues with which the organization is contending.

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