Corouting: An IP Hybrid Routing Approach

Abstract

We propose a hybrid routing scheme that combines traditional shortest-path based OSPF mechanisms as well as a new form of explicit routing executed at the flow level. The scheme consists of finding explicit routes for real-time UDP flows, on network links that -at flow entry time- do not present more than 50% bandwidth utilisation. As for TCP packets, they will be routed on the unique least-cost path found through standard Link State algorithms. The approach improves the robustness and scalability of the network, thanks to its inherent traffic engineering mechanisms and offers better overall service for jitter and delay- sensitive real-time traffic.