SDN and PCE implementations for segment routing

Segment Routing (SR) technology has been proposed to enforce effective routing strategies without relying on signaling protocols. In this paper, two SR implementations are presented and successfully demonstrated in two different network testbeds. The first implementation focuses on a software defined networking (SDN) scenario where nodes consist of OpenFlow switches and the SR Controller is a specifically designed enhanced version of an OpenFlow Controller. The second implementation includes a novel Path Computation Element (PCE) scenario where nodes consist of commercially available IP/MPLS routers and the SR Controller is a new extended version of a PCE solution. Both implementations have been successfully applied to demonstrate dynamic traffic rerouting. In particular, by enforcing different segment list configurations at the ingress node, rerouting is effectively achieved with no packet loss and without requiring the use of signaling protocols.