Microsoft has developed a software platform for data centre networking devices such as switches, using Linux to keep it as open and flexible as possible. It also incorporates a new API designed to support custom programmable logic hardware used to accelerate network functions.
Kamala Subramaniam, Microsoft’s principal architect for Azure networking, said in the post that disaggregating the switch software from the switch hardware will be a growing trend in the networking industry, and the firm is keen to contribute its insights and experiences with the technology.
ACS allows the firm to debug, fix and test software bugs much faster, and provides Microsoft with the flexibility to develop features required for its own data centre and networking requirements, Subramaniam explained.
Microsoft describes ACS as a cross-platform modular operating system built on Linux and designed to run network devices like switches. It is cross-platform in that it will run on hardware from multiple switch vendors, thanks to the Switch Abstraction Interface (SAI) specifications.
SAI is a new open standard API that provides a way for custom logic components such as application-specific integrated circuits (ASICs) to be reprogrammed as required.
“Before SAI, the underlying complexity of the hardware, with its strict coupling of protocol stack software, denied us the freedom to choose the best combination of hardware and software for our networking needs. SAI allows software to program multiple switch chips without any changes, thus making the base router platform simple, consistent and stable,” said Subramaniam.
The fact that Microsoft has decided to use Linux for this purpose is notable, but Subramaniam explained that this allows the firm to make use of the vibrant Linux ecosystem and “use and extend open source, Microsoft and third-party applications” in its network hardware.
ACS was demonstrated at the SIGCOMM conference working with ASICs from Mellanox, Broadcom and Cavium, and interoperating with network application stacks from Dell and Metaswitch, the firm said.
Microsoft also disclosed how it is already using programmable logic in custom network interface controller hardware in its data centres to offload the burden of software-defined networking from the server nodes.