Explanation/Reference:
Explanation: The Session Description Protocol (SDP), defined in RFC 2327, describes the content of sessions, including telephony, Internet radio, and multimedia applications. SDP includes information about
[8]:
Media streams: A session can include multiple streams of differing content. SDP currently defines

audio, video, data, control, and application as stream types, similar to the MIME types used for Internet mail.
Addresses: SDP indicates the destination addresses, which may be a multicast address, for a media

stream.
Ports: For each stream, the UDP port numbers for sending and receiving are specified.

Payload types: For each media stream type in use (for example, telephony), the payload type indicates

the media formats that can be used during the session.
Start and stop times: These apply to broadcast sessions, for example, a television or radio program.

The start, stop, and repeat times of the session are indicated.
Originator: For broadcast sessions, the originator is specified, with contact information. This may be

useful if a receiver encounters technical difficulties.