Editing Session Announcement Protocol (section)

The '''Session Announcement Protocol''' ('''SAP''') is an experimental [[protocol (computing)|protocol]] for advertising [[multicast]] session information. SAP typically uses [[Session Description Protocol]] (SDP) as the format for [[Real-time Transport Protocol]] (RTP) session descriptions. Announcement data is sent using [[IP multicast]] and the [[User Datagram Protocol]] (UDP).

Under SAP, senders periodically transmit SDP descriptions to a well-known [[multicast address]] and [[Port (computer networking)|port number]] (9875).<ref>{{cite web |url=http://www.javvin.com/protocolSAP.html |title=SAP (v1 & v2): Session Announcement Protocol |access-date=2012-04-06 |archive-url=https://archive.today/20130126204537/http://www.javvin.com/protocolSAP.html |archive-date=2013-01-26 |url-status=dead }}</ref> A listening application constructs a guide of all advertised multicast sessions.

SAP was published by the [[IETF]] as RFC 2974.<ref>{{cite IETF |RFC=2974 |title=Session Announcement Protocol |author1=M. Handley |author2=C. Perkins |author3=E. Whelan |date=October 2000}}</ref>