A framework for flexible interdomain routing in transit ISPs

ISPs face difficulties in optimizing interdomain routing due to the single path routing constraint of BGP. A single best path makes it difficult to optimize routing and is unable to satisfy various application requirements of customers. In this paper, we present a new routing architecture for ISP edge network which breaks this constraint and allows the operator to flexibly assign interdomain paths to customers and to use these paths for forwarding. We leverage Software Defined Networking (SDN) to implement this new design while also maintaining compatibility with existing networks. Our preliminary results show that the system is capable of flexible routing and can be integrated to existing infrastructure.