Supporting VNF chains: an implementation using Segment Routing and PCEP

The paradigm of Network Function Virtualization (NFV) requires the underlying networks to be able to route traffic through dynamically deployed nodes. The research presented here demonstrates the feasibility of using segment routing (SR), a modern incarnation of the source routing paradigm, and suitable SDN controllers to accomplish the traffic steering goal. Specifically, we focused on IPv4 SR and built a proof of concept SRMPLS network using Juniper vQFX routers with custom VNFs. The Juniper NorthStar SDN controller was used to build SR- MPLS LSPs via the Path Computation Element Communication Protocol (PCEP). We validated the operation of our proof of concept in two scenarios: VNFs reinstantiation and service chain creation and support. In both cases traffic can be successfully steered through the functions, hence demonstrating for the first time the feasibility of adoption of the proposed technologies.