A Scalable Framework for Segment Routing in Service Provider Networks: The Omnipresent Ethernet Approach

Segment routing has recently been proposed in the IETF towards making IP/MPLS networks service-oriented and efficient. Segment routing involves identifying paths at the source node using adjacency identifiers conjoined together to create a source-routed path. To this end, we propose a transport paradigm that will act as an enabler towards implementing segment routing in service provider networks. Specifically, we use Carrier Ethernet that is gaining acceptance as an IP/MPLS carrier technology. We propose the use of our modification of Carrier Ethernet called Omnipresent Ethernet (based on source routed binary labels embedded in an Ethernet frame) towards implementing segment routing. We evaluate segment routing for large service provider networks and understand scalability limitations of source routing. To absolve the scalability issues, a hierarchical segment routing (H-SR) scheme that uses special nodes called Swap-Nodes is proposed. Three techniques for swap-node selection based on centrality paradigms that facilitate and enhance scalability of segment routing are put forth. A test-bed is built to validate segment routing along with a simulation model to evaluate the proposed hierarchical segment routing scheme.