http://www.rfc-editor.org/rfc/rfc2327.txt
RFC 2327: SDP: Session Description Protocol, M. Handley, V. Jacobson1998-04-01T23:00:00-00:00This document defines the Session Description Protocol, SDP. SDP is intended for describing multimedia sessions for the purposes of session announcement, session invitation, and other forms of multimedia session initiation. [STANDARDS-TRACK]