Design for configurability: rethinking interdomain routing policies from the ground up

Giving ISPs more fine-grain control over interdomain routing policies would help them better manage their networks and offer value-added services to their customers. Unfortunately, the current BGP route-selection process imposes inherent restrictions on the policies an ISP can configure, making many useful policies infeasible. In this paper, we present Morpheus, a routing control platform that is designed for configurability. Morpheus enables a single ISP to safely realize a much broader range of routing policies without requiring changes to the underlying routers or the BGP protocol itself. Morpheus allows network operators to: (1) make flexible trade-offs between policy objectives through a weighted-sum based decision process, (2) realize customer-specific policies by supporting multiple route-selection processes in parallel, and allowing customers to influence the decision processes, and (3) configure the decision processes through a simple and intuitive configuration interface based on the Analytic Hierarchy Process, a decision-theoretic technique for balancing conflicting objectives. We also present the design, implementation, and evaluation of Morpheus as an extension to the XORP software router.