Towards a deployable IP Anycast service

Since it was first described in 1993, IP anycast has been a promising technology for simple, efficient, and robust service discovery, and for connectionless services. Due to scaling issues, the difficulty of deployment, and lack of application-specific features such as load balancing and connection affinity, the use of IP anycast is limited to a small number of critical low-level services such as DNS root server replication. More commonly, application-layer anycast, such as DNS-based redirection, is used. As the number of P2P and overlay services grows, however, the advantages of IP anycast become more appealing. This paper proposes a new proxy overlay deployment model for IP anycast that overcomes most of the limitations of native IP anycast. We believe that this makes IP anycast a viable option for easing deployment and improving the robustness and effi- ciency of many P2P and overlay technologies. We describe the new deployment model, some of its uses for P2P and overlay networks, its pros and cons relative to application-layer anycast, and discuss research issues