http://www.rfc-editor.org/rfc/rfc2974.txt
RFC 2974: Session Announcement Protocol, M. Handley, C. Perkins, E. Whelan2000-10-01T23:00:00-00:00This document describes version 2 of the multicast session directory announcement protocol, Session Announcement Protocol (SAP), and the related issues affecting security and scalability that should be taken into account by implementors. This memo defines an Experimental Protocol for the Internet community.