datatracker.ietf.org
Sign in
Version 5.9.0, 2014-12-18
Report a bug

Connectivity Preconditions for Session Description Protocol (SDP) Media Streams
RFC 5898

Internet Engineering Task Force (IETF)                      F. Andreasen
Request for Comments: 5898                                 Cisco Systems
Category: Standards Track                                   G. Camarillo
ISSN: 2070-1721                                                 Ericsson
                                                                 D. Oran
                                                                 D. Wing
                                                           Cisco Systems
                                                               July 2010

   Connectivity Preconditions for Session Description Protocol (SDP)
                             Media Streams

Abstract

   This document defines a new connectivity precondition for the Session
   Description Protocol (SDP) precondition framework.  A connectivity
   precondition can be used to delay session establishment or
   modification until media stream connectivity has been successfully
   verified.  The method of verification may vary depending on the type
   of transport used for the media.  For unreliable datagram transports
   such as UDP, verification involves probing the stream with data or
   control packets.  For reliable connection-oriented transports such as
   TCP, verification can be achieved simply by successful connection
   establishment or by probing the connection with data or control
   packets, depending on the situation.

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/rfc5898.

Andreasen, et al.            Standards Track                    [Page 1]
RFC 5898                Connectivity Precondition              July 2010

Copyright Notice

   Copyright (c) 2010 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
   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.

Andreasen, et al.            Standards Track                    [Page 2]
RFC 5898                Connectivity Precondition              July 2010

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  Connectivity Precondition Definition . . . . . . . . . . . . .  4
     3.1.  Syntax . . . . . . . . . . . . . . . . . . . . . . . . . .  4
     3.2.  Operational Semantics  . . . . . . . . . . . . . . . . . .  4
     3.3.  Status Type  . . . . . . . . . . . . . . . . . . . . . . .  5
     3.4.  Direction Tag  . . . . . . . . . . . . . . . . . . . . . .  5
     3.5.  Precondition Strength  . . . . . . . . . . . . . . . . . .  5
   4.  Verifying Connectivity . . . . . . . . . . . . . . . . . . . .  6
     4.1.  Correlation of Dialog to Media Stream  . . . . . . . . . .  7
     4.2.  Explicit Connectivity Verification Mechanisms  . . . . . .  7
     4.3.  Verifying Connectivity for Connection-Oriented
           Transports . . . . . . . . . . . . . . . . . . . . . . . .  9
   5.  Connectivity and Other Precondition Types  . . . . . . . . . .  9
   6.  Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

[include full document text]