Session Announcement Protocol (SAP)

Contributor(s): Kim Lindros & Ed Tittel

Session Announcement Protocol (SAP) is a protocol used to define the format and describe the information that will be exchanged during a multicast conferencing session

Content Continues Below

SAP requires announcements to occur periodically, generally with an IP time-to-live (TTL) of 255. Announcements must be sent on Port 9875. To announce a multicast session, the session creator sends a multicast packet to a well-known multicast group using the Session Description Protocol (SDP) to describe the packets. 

Session Announcement Protocol is generally implemented on local area networksand requires multicast connection capabilities in Internet routers to advertise media streams over the Internet. (Multicasting is a standard feature of IPv6 but some IPv4 routers don't implement it. In those cases, the MBone, or multicast Internet backbone, can be used.)

SAP is defined in RFC 2475.

This was last updated in July 2014

Continue Reading About Session Announcement Protocol (SAP)

Dig Deeper on SIP and Unified Communications Standards

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.


File Extensions and File Formats