http://www.rfc-editor.org/rfc/rfc3446.txt
RFC 3446: Anycast Rendevous Point (RP) mechanism using Protocol Independent Multicast (PIM) and Multicast Source Discovery Protocol (MSDP), D. Kim, D. Meyer, H. Kilmer, D. Farinacci2003-01-01T23:00:00-00:00This document describes a mechanism to allow for an arbitrary number of Rendevous Points (RPs) per group in a single shared-tree Protocol Independent Multicast-Sparse Mode (PIM-SM) domain. This memo provides information for the Internet community.