Dell Helps to Advance Switch Abstraction Interface

In the Open Compute Project’s (OCP) continuing quest to open up the world of networking, there is now a new specification known as Switch Abstraction Interface (SAI) that could make a big difference.

The SAI specification was submitted to OCP this week, thanks to the efforts of Dell, Big Switch Networks, Mellanox and Microsoft. SAI is an abstraction layer for switches. It enables a common API interface across network operating systems.

“The SAI will make it easy for Dell to support different networking silicon devices in the future with Dell operating systems,” Subi Krishnamurthy, CTO, Dell Networking, told Enterprise Networking Planet. “This announcement is part of Dell’s Open Networking effort, which we began in January 2014 when Dell became the first Tier One vendor to support an open networking strategy.”

Krishnamurthy noted that the benefits of Dell’s Open Networking effort strategy are simple: it provides the customer greater choice and flexibility vs. a proprietary model. Krishnamurthy added that all future operating systems from Dell will support the SAI. That said, it will not function on top of Dell’s partner or competitor operating systems.

“We expect SAI APIs to be supported by all silicon vendors, including Broadcom, Mellanox and Intel,” Krishnamurthy said. “Thus, with this API, it will be easy to port networking operating systems to different silicon devices and the key here is simplicity and flexibility.”

While the SAI specification was submitted this week, that doesn’t mean that it immediately becomes an OCP-recommended approach. Krishnamurthy explained that OCP operates on differing timetables for various submissions. He commented that SAI has been submitted and the expectation is that it will be accepted soon, but other than that, he could not provide a more detailed estimate for the time being.

OCP already has multiple specifications, including the Open Network Install Environment (ONIE), which enables different vendor operating systems to run on the same hardware device. Krishnamurthy explained that SAI and ONIE are not directly interrelated, but are separate technologies.

“The SAI provides another layer between the OS and physical silicon on the switch,” Krishnamurthy said. “As a result, programmers don’t have to worry about tailoring networking OS code for each of the many different brands of networking silicon and instead, they can now focus more on the unique needs of differing customers.”

From a technology perspective, Krishnamurthy explained that at this point, SAI functions by mainly abstracting switch ASICs.

“SAI can also be applied to FPGAs with switching functionality,” Krishnamurthy said. “It is not designed, however, for the control plane microprocessors.”

Sean Michael Kerner is a senior editor at Enterprise Networking Planet and InternetNews.com. Follow him on Twitter @TechJournalist.