Route Distribution Incentives

TL;DR

This paper models BGP route distribution as a game with incentives, analyzing convergence and equilibrium existence in simple graph structures to understand how incentives influence routing outcomes.

Contribution

It introduces a game-theoretic model for BGP route distribution with incentives, analyzing convergence and equilibrium in line, tree, and ring graph topologies.

Findings

BGP dynamics converge to a unique outcome in simple topologies.

Equilibria exist under certain conditions in the game model.

In ring graphs, competition affects route distribution and incentives.

Abstract

We present an incentive model for route distribution in the context of path vector routing protocols and we focus on the Border Gateway Protocol (BGP). BGP is the de-facto protocol for interdomain routing on the Internet. We model BGP route distribution and computation using a game in which a BGP speaker advertises its prefix to its direct neighbors promising them a reward for further distributing the route deeper into the network, the neighbors do the same thing with their neighbors, and so on. The result of this cascaded route distribution is an advertised prefix and hence reachability of the BGP speaker. We first study the convergence of BGP protocol dynamics to a unique outcome tree in the defined game. We then proceed to study the existence of equilibria in the full information game considering competition dynamics. We focus our work on the simplest two classes of graphs: 1) the line (and the tree) graphs which involve no competition, and 2) the ring graph which involves competition.