Accessing Cloud with Disaggregated Software-Defined Router

The last decade has witnessed a rapid growth of public clouds. More and more enterprises are deploying their applications on the cloud platform. As one of the largest public cloud providers, Tencent cloud serves tens of Tbps inbound/outbound traffic via cloud gateways for customers with diverse cloud access requirements. Traditionally, cloud gateways were built with proprietary routers. From years of experience operating cloud network, we found that commodity router based cloud gateways are hard to scale, lack of extensibility and are difficult to inter-operate with the SDN-based cloud networks. To this end, we build our own Disaggregated Software-defined Router (DSR) to serve cloud access traffic. We architecturally split cloud router functionalities into several disjoint modules: 1) an access module built out of off-the-shelf commodity switches; 2) a software-based fast and scalable forwarding module; 3) a robust and scalable routing module built with commodity servers; 4) an SDN control module for traffic management and devices configuration. All the components can be independently scaled and maintained. DSR can deliver new network features at high velocity and has sustained the rapid growth of the cloud access traffic. In this paper, we present the design, implementation and our years of operational experiences of DSR.