Towards a Unified Theory of Policy-Based Routing

The Border Gateway Protocol (BGP) has stimulated renewed interest in routing protocols and in formal methods required to prove their convergence properties. Many routing algebras are motivated to generalise minimum-weight routing and to establish generalised conditions of non-negative weights and absence of a negative cycle. Those sufficient conditions ensure the existence of stable routings. In our paper, we attempt to provide a unified theory from which all of those seemingly disparate sufficient conditions can be derived. This talk mainly presents the basic ideas of routing algebras and its application to policy-based routing.