Media Resource Control Protocol Version 2 (MRCPv2)
RFC 6787

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 27
• 28

Internet Engineering Task Force (IETF)                        D. Burnett
Request for Comments: 6787                                         Voxeo
Category: Standards Track                                  S. Shanmugham
ISSN: 2070-1721                                      Cisco Systems, Inc.
                                                           November 2012

           Media Resource Control Protocol Version 2 (MRCPv2)

Abstract

   The Media Resource Control Protocol Version 2 (MRCPv2) allows client
   hosts to control media service resources such as speech synthesizers,
   recognizers, verifiers, and identifiers residing in servers on the
   network.  MRCPv2 is not a "stand-alone" protocol -- it relies on
   other protocols, such as the Session Initiation Protocol (SIP), to
   coordinate MRCPv2 clients and servers and manage sessions between
   them, and the Session Description Protocol (SDP) to describe,
   discover, and exchange capabilities.  It also depends on SIP and SDP
   to establish the media sessions and associated parameters between the
   media source or sink and the media server.  Once this is done, the
   MRCPv2 exchange operates over the control session established above,
   allowing the client to control the media processing resources on the
   speech resource server.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6787.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents

Burnett & Shanmugham         Standards Track                    [Page 1]
RFC 6787                         MRCPv2                    November 2012

   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   8
   2.  Document Conventions  . . . . . . . . . . . . . . . . . . . .   9
     2.1.   Definitions  . . . . . . . . . . . . . . . . . . . . . .  10
     2.2.   State-Machine Diagrams . . . . . . . . . . . . . . . . .  10
     2.3.   URI Schemes  . . . . . . . . . . . . . . . . . . . . . .  11
   3.  Architecture  . . . . . . . . . . . . . . . . . . . . . . . .  11
     3.1.   MRCPv2 Media Resource Types  . . . . . . . . . . . . . .  12
     3.2.   Server and Resource Addressing . . . . . . . . . . . . .  14
   4.  MRCPv2 Basics . . . . . . . . . . . . . . . . . . . . . . . .  14
     4.1.   Connecting to the Server . . . . . . . . . . . . . . . .  14
     4.2.   Managing Resource Control Channels . . . . . . . . . . .  14
     4.3.   SIP Session Example  . . . . . . . . . . . . . . . . . .  17
     4.4.   Media Streams and RTP Ports  . . . . . . . . . . . . . .  22
     4.5.   MRCPv2 Message Transport . . . . . . . . . . . . . . . .  24
     4.6.   MRCPv2 Session Termination . . . . . . . . . . . . . . .  24
   5.  MRCPv2 Specification  . . . . . . . . . . . . . . . . . . . .  24
     5.1.   Common Protocol Elements . . . . . . . . . . . . . . . .  25
     5.2.   Request  . . . . . . . . . . . . . . . . . . . . . . . .  28
     5.3.   Response . . . . . . . . . . . . . . . . . . . . . . . .  29
     5.4.   Status Codes . . . . . . . . . . . . . . . . . . . . . .  30
     5.5.   Events . . . . . . . . . . . . . . . . . . . . . . . . .  31