Better Internet routing through intrinsic support for selfishness

The BGP routing system is inflexible and sub-optimal for both stub networks and ISPs. Stub networks are unable to obtain routes that meet their end-to-end requirements, and ISPs have limited flexibility in controlling their revenues and offering new services to a wide customer base. We present the S4R supplemental routing system to address these shortcomings. Technical soundness and economic viability are equal first class design requirements for S4R. In S4R, ISPs announce links connecting different parts of the Internet. ISPs can selfishly price their links to attract maximal amount of traffic. Stub networks can selfishly select paths that best meet their requirements at the lowest cost. We design a variety of practical algorithms for ISP and stub network response that strike a balance between accommodating the (selfish) objectives of all participants and ensuring efficient and stable operation overall. We employ large scale simulations of realistic scenarios to show that S4R operates at a close-to-optimal state and that it encourages broad participation from stubs and ISPs. We describe a prototype implementation using OpenFlow and show that it can support S4R effectively.