Hybrid routing for scalable IP/MPLS traffic engineering

This paper presents performance data for a new hybrid routing method (HRM) for IP network traffic engineering. In this method, the major traffic streams between some source/destination pairs is routed via MPLS constraint based routing, while the remaining traffic is routed via conventional IGP routing. When Internet traffic is heavy-tailed distributed, consisting of a few "elephant" and many "mice" flows, our traffic engineering results indicate that our HRM normally needs just a small number of tunnels to achieve a network performance that is comparable to that of fully meshed MPLS network. The method has been used to implement a HRM traffic engineering tool. The tool enables network operators to visualize and manage traffic to avoid congestion, as well as to decide where to place MPLS routers and tunnels.