Equilibrium routing: From theory to practice

Competitive routing across peering links is a notable problem in Internet routing. A few years ago, a proposal to incrementally modify the Border Gateway Protocol (BGP) decision process was done, to improve routing coordination by leveraging on the existing multi-exit discriminator BGP attribute as signaling medium among peering Internet networks. It is called Peering Equilibrium Multipath (PEMP) routing: based on a non-cooperative potential game, it can improve routing stability and efficiency while respecting unilateral routing choice, by supporting strategic multipath forwarding decisions. The contribution of this paper is twofold. First, we specify how weighted load-balancing should be done in PEMP routing and examine the benefits against even load-balancing. Then we document an implementation of PEMP routing in the Quagga open source router, better specifying some aspects. We provide a performance evaluation of the implemented PEMP routing system, showing that the computing overhead is limited.