SAN Valley links FC SANs over IP networks


At the upcoming Networld+Interop show (May 6-11 in Las Vegas), SAN Valley Systems is expected to announce a gateway that will enable companies to link Fibre Channel storage area networks (SANs) over optical IP networks. Shipments of the SL1000 IP-SAN Gateway are due in June.

Applications that can benefit from IP-based storage include disaster recovery (such as mirroring and data replication), resource consolidation, and managed storage services.

SAN Valley is a relatively early entrant in a market that will become increasingly crowded this year. The company will compete to varying degrees with vendors like Cisco (through a collaboration with Brocade as well as the acquisition of NuSpeed), Crossroads, Computer Network Technology (CNT), Entrada, FalconStor, Lucent (via a partnership with Vixel), Netconvergence, Nishan Systems, and SANcastle.

Most of those vendors have yet to ship product. Exceptions include FalconStor and Nishan (see InfoStor, March 2001, p. 1), and CNT, which was first to market with SAN-over-IP more than a year ago. Cisco is expected to ship a competing product this summer.

SAN Valley officials characterize their technology approach as "managed encapsulation" and contrast it with other approaches that include software-based routing (protocol conversion from Fibre Channel to Gigabit Ethernet), native-attach switching, and software-based tunneling. Managed encapsulation is also a tunneling approach, but it relies on a combination of hardware and software.

"A lot of the problems and issues associated with tunneling were implementation problems and are not inherent to the technology itself. We've solved those problems," claims Rick Walsworth, vice president of marketing at SAN Valley.

SAN Valley officials claim that each of the other approaches has drawbacks, most often high latency (and relatively low performance), low port counts, and high per-port prices. (The company had not set pricing for the SL1000 IP-SAN Gateway at press time.) On the performance front, SAN Valley officials claim wire speeds, or close to 200MBps in duplex mode.

Using SAN Valley's version of the evolving FC-IP specification, users can build multi-node, extensible SANs across IP networks.
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The SL1000 handles encapsulation and de-encapsulation of storage traffic. The gateway includes four independent channels, each with one Gigabit Ethernet port and one Fibre Channel port.

SAN Valley developed a single chip that incorporates Fibre Channel and Gigabit Ethernet Media Access Control (MAC) devices, referred to as a managed encapsulation engine, which enables communications via packetized protocols. This allows the gateway to move any Fibre Channel protocol over an IP network in a way that is transparent to the Fibre Channel SANs.

For bandwidth management, SAN Valley plans to provide functions such as Quality of Service (QoS) and traffic shaping (the ability to control the amount of data that a Fibre Channel network puts out onto a Gigabit Ethernet network).

Since all of the various approaches to linking Fibre Channel SANs over IP WANs will eventually rely on standards that have yet to be finalized-such as FC-IP and iSCSI-all the approaches could be considered proprietary. SAN Valley plans to make its gateway compliant with standards such as FC-IP and iSCSI in a phased-in approach, as do most of its competitors.

For example, SAN Valley's first gateway implementation is a proprietary version of the FC-IP specification. An implementation due in the first half of next year will be fully compatible with the FC-IP standard. And, in the third phase of SAN Valley's rollout, expected in the first half of 2003, the product will be compatible with the iSCSI and FC-IP standards, both of which are under development in the Internet Engineering Task Force (IETF).

This article was originally published on April 01, 2001