Path-Vector Contract Routing

Many recently proposed clean slate Internet architectures essentially depend on more flexible and extended representation of Internet topology on which next generation routing protocols may operate. Representation of neighboring relationships between Internet Service Providers (ISPs) in finer granularity is promising to overcome many shortcomings of the current Internet architecture. Similarly, contract-switching paradigm promotes an ISP to define itself as a set of edge-to-edge (g2g) links that connect ingress and egress routers of its domain. Each link is represented by a contract which defines not only neighboring relationships with other domains but also economic (e.g., price), performance (e.g., quality of service parameters) and temporal (e.g., lifetime of the dedicated link) attributes attached to this g2g link. In this work, we introduce Path-Vector Contract Routing (PVCR) protocol which allows multi-metric, multi-hop negotiation of end-to-end inter-domain paths by leveraging path-vector style construction on top of g2g contract definitions. Our analysis on synthetic and real-world topologies show that Path-Vector Contract Routing has many promising properties such as rich route diversity, end-to-end multi-domain QoS and low control traffic. We also investigate inter-domain traffic engineering capabilities of PVCR which inherently considers economics of routing in its opportunistic settings.