SCTP for robust and flexible IP anycast services

Abstract

IP anycast is a powerful network layer mechanism that can be used for transparent communications between clients and a distributed service infrastructure. Unfortunately, large-scale deployment of IP anycast would cause a number of severe problems, including excessive routing table growth and potential routing instability. In order to solve these problems, a number of overlay network architectures have been proposed over the last years. In this paper we show that the robustness of anycast services provided via such anycast architectures can be significantly improved by using SCTP transport layer facilities. More specifically, the proposed approach adds the following important features to existing anycast overlays: Robustness to anycast overlay node failure or network reconfiguration, seamless anycast service delivery to mobile clients, and true stateful anycast communications over an entirely stateless infrastructure. Furthermore, we argue that the number of overlay nodes can be drastically reduced in comparison with the earlier architectures, without degrading service quality or increasing the end-to-end path stretch.