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Playlist "All Systems Go! 2023"

Disaggregated networks: Is network hardware special?

Paul Menzel

Despite being ordinary computers with an ASIC for switching, in reality network hardware must still be treated differently from normal servers. In recent years a lot has improved, and vendors offer white box switches, allowing users to install a (network) operating system of their choice. Of course, the NOS needs to support the firmware interface for the particular ASIC, and this is not standardized: swtitchdev, DSA, SAI – none of them supporting all devices. Due to SONiC dominance, a lot of vendors seem to support SAI (Switch Abstraction Interface). But SAI requires a proprietary external Linux kernel module. On the NOS side, Open Network Linux was abandoned, and Azure’s SONiC is the new popular kid on the block, running a Docker daemon. There are other differences in the network hardware ecosystem: For example ONIE as the bootloader environment. Also working with upstream and using established software developing practices are lacking, resulting in a maintenance burden. Projects like DENT or OpenWrt go one step further by only supporting upstream Linux kernel interfaces, but now dentOS is also going to support SAI.

This talk gives a short introduction into the network operating systems, and then focuses on DENT with the ONL fork dentOS, and shares experiences. Curiously, problems how to treat firmware blobs and discussions about what distribution to use as a base, are not unknown to these projects either.