1. Introduction

When initiating multimedia teleconferences, voice-over-IP calls, streaming video, or other sessions, there is a requirement to convey media details, transport addresses, and other session description metadata to the participants.

SDP provides a standard representation for such information, irrespective of how that information is transported. SDP is purely a format for session description -- it does not incorporate a transport protocol, and it is intended to use different transport protocols as appropriate, including the Session Announcement Protocol (SAP) [RFC2974], Session Initiation Protocol (SIP) [RFC3261], Real-Time Streaming Protocol (RTSP) [RFC7826], electronic mail [RFC5322] using the MIME extensions [RFC2045], and the Hypertext Transport Protocol (HTTP) [RFC7230].

SDP is intended to be general purpose so that it can be used in a wide range of network environments and applications. However, it is not intended to support negotiation of session content or media encodings: this is viewed as outside the scope of session description.

This memo obsoletes [RFC4566]. The changes relative to [RFC4566] are outlined in Section 10 of this memo.

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