This letter is in response to an article that appeared in InfoStor's September issue, "Drawing the lines on IP storage networking", written by Marc Farley. I want to set the record straight about Adaptec's EtherStorage technology.
The article points out that two technology approaches to IP storage exist: tunneling and native IP storage, and that Adaptec is among the companies leading the native IP storage charge. True. Adaptec is focused on enabling native IP-based SANs for a broad, mainstream market. Native IP storage is an alternative for environments that are either Ethernet-centric or for smaller environments that would like the benefits of SANs but where Fibre Channel may be too expensive.
The article further states that Adaptec's EtherStorage avoids TCP. Untrue. Adaptec's EtherStorage products will support TCP at the transport layer and will work across any existing IP infrastructure, including standard switches. Adaptec's EtherStorage products will be fully compatible with switches and routers that manage flows and priorities at the TCP level.
In addition to TCP, EtherStorage products will support an alternative Adaptec-developed transport layer (SAN Transport Protocol) that is more efficient and easier to implement in LAN environments that are common in the target markets described above. Supporting both pure TCP and an adapted TCP layer that is more robust in LAN storage environments expands the applicability of native IP storage to a broader market. Adaptec is committed to making native IP SANs available to a broad market, and in keeping with this strategy, will license this additional protocol to interested companies. This dual transport layer approach will allow customers to deploy storage across Gigabit Ethernet LANs, MANs and WANs using whichever protocol is best suited for the network environment being traversed.
Both Fibre Channel and the various IP storage proposals are based on using SCSI command protocols from the OS storage stack layer to the storage devices. The network carrying those commands (parallel bus, Fibre Channel, Ethernet) is largely invisible. Adaptec is a leading participant in efforts to enable the use of all three interconnect fabric technologies- Fibre Channel, Ethernet, and InfiniBand.
Others companies involved in network fabric components and switches are driving efforts to tunnel encapsulated SCSI protocols like Fibre Channel across different network fabrics, which typically use IP for the network layer. We also welcome those efforts, which should also result in broader accessibility of storage.
Adaptec fully supports the efforts of the Internet Engineering Task Force (IETF) to develop and ratify IP storage standards, and is a member of the working committee developing the draft standards. We recognize that optimal standards incorporate the best ideas and approaches in a cooperative effort. Adaptec, Cisco, IBM and others are working together towards open standards to be used by the industry at large.
Senior Marketing Manager
Storage Networking Solutions Group