Towards Reduced-State Service Chaining with Source Routing

The widespread adoption of Network Function Virtualization (NFV) poses significant dataplane scalability limitations in datacenters (DC), as switches will be required to maintain a large amount of forwarding state for service chaining. This problem is exacerbated by the small Forwarding Information Base (FIB) of commodity switches, which are typically deployed in NFV infrastructures. To mitigate this problem, we present a routing fabric that combines source routing with pathlet switching in order to (i) achieve state reduction and (ii) provide support for longer paths, hence, meeting the increased hop-count requirement of service chains. Coupling the proposed source routing fabric with a service chain embedding method, we achieve significant gains in terms of FIB consumption, request acceptance, and revenue generation.