AVS for Vendor Sim and Topologies with Broadcom, Arista

Author: Sonica, Google; Runip (Ronip), Broadcom Device Architecture Group Collection: 2025-OCP-Global-Summit-Networking

Summary

This talk presents the Alpine Virtual Switch (AVS), Google's next-generation SONiC virtual switch framework that supports pluggable high-fidelity data plane implementations. The Alpine framework has three components: Alpine Virtual Switch (AVS) itself — a two-container Kubernetes pod design separating the SONiC switch stack VM from a replaceable ASIC simulation container; ACTIVE (Alpine KNE Test Bed) — deployment of virtual switches in large-scale virtual topologies using KNE (Kubernetes Network Emulation); and Apex — cloud execution infrastructure for pre/post-submit CI/CD test runs.

The talk focuses on integrating Broadcom's BCM SIM into AVS, and separately on early collaboration with Arista to deploy AVS as a standalone switch in SONiC topologies. BCM SIM is Broadcom's high-fidelity device model for their switching ASICs, with a library of 70+ device models available since 2004. It provides interface-accurate and register-accurate modeling of ingress/egress pipelines and MMU forwarding behavior, enabling pre-tape-out software development with SDK/SAI Early Availability shipped to customers months before silicon arrives. The integration uses a proprietary "vBridge" component that interfaces the BCM SIM device model to the Alpine KNE virtual interface fabric, supporting packet TX/RX and link state propagation. A PoC deploying 100 AVS nodes on 40 GCE nodes was demonstrated for large-scale fabric simulation.