RTSP、RTP、RTCP

Network Working Group H. Schulzrinne

Request for Comments: 2326 Columbia U.

Category: Standards Track A. Rao

Netscape

R. Lanphier

RealNetworks

April 1998

Real Time Streaming Protocol (RTSP)

Status of this Memo

Copyright (C) The Internet Society (1998). All Rights Reserved.

Abstract

The Real Time Streaming Protocol, or RTSP, is an application-level

protocol for control over the delivery of data with real-time

properties. RTSP provides an extensible framework to enable

controlled, on-demand delivery of real-time data, such as audio and

video. Sources of data can include both live data feeds and stored

clips. This protocol is intended to control multiple data delivery

sessions, provide a means for choosing delivery channels such as UDP,

multicast UDP and TCP, and provide a means for choosing delivery

+ 1.4 Protocol Properties ................................... 9

+ 1.5 Extending RTSP ........................................ 11

+ 1.6 Overall Operation ..................................... 11

+ 1.7 RTSP States ........................................... 12

+ 1.8 Relationship with Other Protocols ..................... 13

* 2 Notational Conventions ....................................... 14

* 3 Protocol Parameters .......................................... 14

+ 3.1 RTSP Version .......................................... 14

Schulzrinne, et. al. Standards Track [Page 1]

RFC 2326 Real Time Streaming Protocol April 1998

+ 3.4 Session Identifiers ................................... 16

+ 3.5 SMPTE Relative Timestamps ............................. 16

+ 3.6 Normal Play Time ...................................... 17

+ 3.7 Absolute Time ......................................... 18

+ 3.8 Option Tags ........................................... 18

o 3.8.1 Registering New Option Tags with IANA .......... 18

* 4 RTSP Message ................................................. 19

+ 4.2 Message Headers ....................................... 19

+ 4.4 Message Length ........................................ 20

* 8 Entity ....................................................... 27

+ 8.1 Entity Header Fields .................................. 27

+ 8.2 Entity Body ........................................... 28

* 9 Connections .................................................. 28

+ 9.1 Pipelining ............................................ 28

+ 9.2 Reliability and Acknowledgements ...................... 28

* 10 Method Definitions .......................................... 29

+ 10.1 OPTIONS .............................................. 30

+ 10.2 DESCRIBE ............................................. 31

+ 10.3 ANNOUNCE ............................................. 32

+ 10.4 SETUP ................................................ 33

+ 10.5 PLAY ................................................. 34

+ 10.6 PAUSE ................................................ 36

+ 10.8 GET_PARAMETER ........................................ 37

+ 10.10 REDIRECT ............................................ 39

o 11.1.1 250 Low on Storage Space ...................... 41

+ 11.2 Redirection 3xx ...................................... 41

+ 11.3 Client Error 4xx ..................................... 42

o 11.3.1 405 Method Not Allowed ........................ 42

o 11.3.2 451 Parameter Not Understood .................. 42

o 11.3.3 452 Conference Not Found ...................... 42

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RFC 2326 Real Time Streaming Protocol April 1998

o 11.3.6 455 Method Not Valid in This State ............ 42

o 11.3.7 456 Header Field Not Valid for Resource ....... 42

o 11.3.8 457 Invalid Range ............................. 43

o 11.3.9 458 Parameter Is Read-Only .................... 43

o 11.3.10 459 Aggregate Operation Not Allowed .......... 43

o 11.3.11 460 Only Aggregate Operation Allowed ......... 43

o 11.3.12 461 Unsupported Transport .................... 43

o 11.3.14 551 Option not supported ..................... 43

+ 12.1 Accept ............................................... 46

+ 12.10 Connection .......................................... 49

+ 12.11 Content-Base ........................................ 49

+ 12.12 Content-Encoding .................................... 49

+ 12.13 Content-Language .................................... 50

+ 12.14 Content-Length ...................................... 50

+ 12.15 Content-Location .................................... 50

+ 12.16 Content-Type ........................................ 50

+ 12.17 CSeq ................................................ 50

+ 12.18 Date ................................................ 50

+ 12.19 Expires ............................................. 50

+ 12.20 From ................................................ 51

+ 12.21 Host ................................................ 51

+ 12.22 If-Match ............................................ 51

+ 12.24 Last-Modified........................................ 52

+ 12.26 Proxy-Authenticate .................................. 52

+ 12.31 Retry-After ......................................... 54

+ 12.32 Require ............................................. 54

+ 12.33 RTP-Info ............................................ 55

+ 12.34 Scale ............................................... 56

+ 12.35 Speed ............................................... 57

+ 12.36 Server .............................................. 57

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RFC 2326 Real Time Streaming Protocol April 1998

+ 12.39 Transport ........................................... 58

+ 12.40 Unsupported ......................................... 62

+ 12.41 User-Agent .......................................... 62

+ 12.42 Vary ................................................ 62

+ 12.43 Via ................................................. 62

+ 12.44 WWW-Authenticate .................................... 62

* 13 Caching ..................................................... 62

+ 14.1 Media on Demand (Unicast) ............................ 63

+ 14.3 Single Stream Container Files ........................ 67

+ A.2 Server State Machine .................................. 77

* B Interaction with RTP ......................................... 79

* C Use of SDP for RTSP Session Descriptions ..................... 80

+ C.1 Definitions ........................................... 80

o C.1.1 Control URL .................................... 80

o C.1.2 Media streams .................................. 81

o C.1.3 Payload type(s) ................................ 81

o C.1.4 Format-specific parameters ..................... 81

o C.1.5 Range of presentation .......................... 82

o C.1.6 Time of availability ........................... 82

o C.1.7 Connection Information ......................... 82

o C.1.8 Entity Tag ..................................... 82

+ C.2 Aggregate Control Not Available ....................... 83

* D Minimal RTSP implementation .................................. 85

o D.1.1 Basic Playback ................................. 86

* E Authors’ Addresses ........................................... 88

* F Acknowledgements ............................................. 89

* References ..................................................... 90

* Full Copyright Statement ....................................... 92

Schulzrinne, et. al. Standards Track [Page 4]

RFC 2326 Real Time Streaming Protocol April 1998

1.1 Purpose

The Real-Time Streaming Protocol (RTSP) establishes and controls

either a single or several time-synchronized streams of continuous

media such as audio and video. It does not typically deliver the

continuous streams itself, although interleaving of the continuous

media stream with the control stream is possible (see Section 10.12).

multimedia servers.

The set of streams to be controlled is defined by a presentation

Alternatively, it may use a connectionless transport protocol such as

UDP.

The streams controlled by RTSP may use RTP [1], but the operation of

RTSP does not depend on the transport mechanism used to carry

continuous media. The protocol is intentionally similar in syntax

and operation to HTTP/1.1 [2] so that extension mechanisms to HTTP

can in most cases also be added to RTSP. However, RTSP differs in a

number of important aspects from HTTP:

* RTSP introduces a number of new methods and has a different

protocol identifier.

* An RTSP server needs to maintain state by default in almost all

* Both an RTSP server and client can issue requests.

exception to this.)

carries only the absolute path in the request and puts the host

name in a separate header field.

This makes "virtual hosting" easier, where a single host with one

IP address hosts several document trees.

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