The switch was introduced yesterday in a blog posting credited to Facebook engineers Alex Eckert, Luis Martin Garcia, Reza Niazmand, and Xu Wang. They note that the Wedge 100 is already being used by Facebook in production; the real news is that the design has been accepted by the Open Compute Project (OCP).
Obviously, Facebook reused a lot of its previous Wedge 40 switch to produce the new design, but 100-Gb/s data transmissions require some extra care, particularly when it comes to optics.
Specifically, Facebook wanted to be able to drop a Wedge 100 into any spot occupied by a Wedge 40. It sounds simple enough, but this feature “required changes from the physical layer all the way up to our monitoring stack,” the team writes.
It meant not only adopting the design for 100-Gb/s optics, but also paying attention to the strength of the optical signal. The analog nature of optical signaling — it all relies on the physics of light waves — makes it tricky, and factors such as signal strength loom larger at higher transmission rates.
Some of Wedge’s most novel aspects are physical. For the Wedge 100, Facebook built a top cover that can be removed without tools, and the fan trays can be removed just by pressing a clip.
But the biggest challenges were operational, “specifically the configuration, provisioning, and managing of Wedge 40 and Wedge 100 in parallel in our network,” the team writes. They don’t give specifics about what needed fixing, but they note that the FBoss team, which writes the operating-system software for Wedge, also writes the management and packet-forwarding software.
Facebook is running the FBoss operating system on Wedge 100, of course. Commercially available operating systems for the switch include Open Network Linux (ONL) from Big Switch Networks and Ubuntu Core from Canonical.
Photo: Wedge Antilles. Don’t tell us you don’t know Wedge Antilles.