1. Introduction

1. Introduction

   This profile defines aspects of RTP left unspecified in the RTP Version 2 protocol definition (RFC 3550) [1]. This profile is intended for the use within audio and video conferences with minimal session control. In particular, no support for the negotiation of parameters or membership control is provided. The profile is expected to be useful in sessions where no negotiation or membership control are used (e.g., using the static payload types and the membership indications provided by RTCP), but this profile may also be useful in conjunction with a higher-level control protocol.

   Use of this profile may be implicit in the use of the appropriate applications; there may be no explicit indication by port number, protocol identifier or the like. Applications such as session directories may use the name for this profile specified in Section 11.

   Other profiles may make different choices for the items specified here.

   This document also defines a set of encodings and payload formats for audio and video. These payload format descriptions are included here only as a matter of convenience since they are too small to warrant separate documents. Use of these payload formats is NOT REQUIRED to use this profile. Only the binding of some of the payload formats to static payload type numbers in Tables 4 and 5 is normative.

1.1 Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [2] and indicate requirement levels for implementations compliant with this RTP profile.

This document defines the term media type as dividing encodings of audio and video content into three classes: audio, video and audio/video (interleaved).