During Cisco Live Europe 2017 (where I got thanks to the Tech Field Day crew kindly inviting me) I had a nice chat with Peter Jones, principal engineer @ Cisco Systems. We started with a totally tangential discussion on why startups fail, and quickly got back to flexible hardware and why one would want to have it in a switch.
Next we discussed the various switching implementations, from software-based switching to network processors (NPUs), programmable ASICs and fixed ASICs. Oh, we also mentioned why ASICs are called ASICs (or “what is application-specific in them”)
We couldn’t resist going deeper and discussing some of the NPU implementation details, and the differences between NPUs and programmable ASICs, but quickly recovered and did a brief overview of where you’d find various chips in Cisco’s products (because Peter works for Cisco).
Next we focused on UADP ASIC used in Catalyst campus switches, briefly explored the idea of virtual hamsters, reverted to being serious and started discussing UADP header parsing, forwarding pipeline, MPLS and SPAN implementation on UADP, and finally what goes into individual stages in the forwarding pipeline, and how the forwarding pipeline uses TCAM.
Last but definitely not least; we couldn’t resist mentioning VXLAN encapsulation, CampusFabric and Geneva.
Even More Details
- Programmable ASICs for Cisco Catalyst Switches from Tech Field Day Extra @ CLEUR 2017
- Enterprise ASIC discussion with Dave Zacks from Tech Field Day Extra @ CLEUR 2016
- Cisco Enterprise Silicon Cisco Live session by Peter Jones
- Security and ASICs Cisco Champion Radio episode
- Cartesian product TCAM explosion