View source for SAP

{{Protocol|SAP}}
{{wikipedia|Session Announcement Protocol}}
'''SAP''' stands for '''Session Announcement Protocol'''.
It is defined in [https://tools.ietf.org/html/rfc2974 RFC 2974].<br />
It uses [[multicast]] to announce streams efficiently on a Local Area Network or on the [[MBONE]]:
any computer on the network can receive announces from all others without any manual configuration.

SAP conveys [[SDP]]'s to describe streams parameters. This can include an [[RTSP]] control URL to use for setting up the stream, or a multicast group address to subscribe to. The SDP also includes port numbers and audio/video codecs parameters, and a stream name, etc.

This technique allows a lot of server to emit streams (often multicasted) and announce them on the network.
Clients on the network can then listen for these announces.<br />
VLC can do this with the "SAP" service discovery plugin.<br />
You then get a listing of all these streams and can simply ''tune'' into the stream of your choice.

Because SAP uses [[multicast]] (as do [[UPnP]] and Apple [[wikipedia:Bonjour (software)|Bonjour]]), it can normally only operate on a Local area network.<br />
Unless your computer is connected to the [[MBONE]], you cannot use SAP to advertise your streams onto the Internet, nor can you receive streams from other places.

== See also ==
* [[MiniSAPServer]]
* [http://www.uninett.no/multimedia/streamingguide/alle.html Example of what is announced via SAP on the MBONE]{{dead link}}


[[Category:Protocols]]