Media Gateway Control Protocol (MGCP) Return Code Usage
RFC 3661

Document Type RFC - Informational (December 2003; No errata)
Updates RFC 3435
Last updated 2015-10-14
Stream ISE
Formats plain text pdf html bibtex
Stream ISE state (None)
Consensus Boilerplate Unknown
Document shepherd No shepherd assigned
IESG IESG state RFC 3661 (Informational)
Telechat date
Responsible AD Jon Peterson
Send notices to (None)
Network Working Group                                          B. Foster
Request for Comments: 3661                                C. Sivachelvan
Updates: 3435                                              Cisco Systems
Category: Informational                                    December 2003

        Media Gateway Control Protocol (MGCP) Return Code Usage

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2003).  All Rights Reserved.

Abstract

   This document provides implementation guidelines for the use of
   return codes in RFC 3435, Media Gateway Control Protocol (MGCP)
   Version 1.0.  Return codes in RFC 3435 do not cover all possible
   specific situations that may ever occur in a gateway.  That is not
   possible and not necessary.  What is important is to ensure that the
   Call Agent that receives a return code behaves appropriately and
   consistently for the given situation.  The purpose of this document
   is to provide implementation guidelines to ensure that consistency.

Table of Contents

   1.  Introduction. . . . . . . . . . . . . . . . . . . . . . . . .   2
       1.2.  Document Organization . . . . . . . . . . . . . . . . .   2
   2.  Return Code Usage . . . . . . . . . . . . . . . . . . . . . .   2
       2.1.  Return Code Categories. . . . . . . . . . . . . . . . .   2
       2.2.  Return Code Situations and Categories . . . . . . . . .   3
       2.3.  Summary of Return Code Categories . . . . . . . . . . .  19
   3.  Additional Guidelines . . . . . . . . . . . . . . . . . . . .  21
       3.1.  Gateway Recommendations . . . . . . . . . . . . . . . .  21
       3.2.  Call Agent Recommendations. . . . . . . . . . . . . . .  21
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .  22
   5.  Acknowledgements. . . . . . . . . . . . . . . . . . . . . . .  22
   6.  Normative References. . . . . . . . . . . . . . . . . . . . .  22
   7.  Authors' Addresses. . . . . . . . . . . . . . . . . . . . . .  23
   8.  Full Copyright Statement. . . . . . . . . . . . . . . . . . .  24

Foster & Sivachelvan         Informational                      [Page 1]
RFC 3661                 MGCP Return Code Usage            December 2003

1.  Introduction

   This document provides implementation guidelines for the use of
   return codes in the Media Gateway Control Protocol MGCP 1.0 [1].
   Return codes in [1] do not cover all possible specific situations
   that may ever occur in the gateway.  That is not possible and not
   necessary.  What is important is to ensure that the Call Agent that
   receives that return code behaves appropriately and consistently for
   the situation that occurred.  The solution described in this document
   is to categorize return codes that gateways return based on the
   expected behavior for the Call Agents that receive them.

   Categorizing errors helps both Call Agent and gateway developers: it
   helps gateway developers choose an appropriate return code when a
   specific one for the situation is not available; it also helps Call
   Agent developers ensure that there is consistent behavior for the
   return code that is received.

1.2.  Document Organization

   In addition to categorizing return codes (section 2.1), section 2.2
   provides a consolidated list of return codes in terms of "situations"
   that may have triggered and the "categories" that they fall under.
   This provides some additional implementation guidelines for the use
   of these return codes.  Section 2.3 includes a summary of the return
   codes and their categories.  Section 3 provides some additional
   implementation guidelines for Call Agent and gateway developers.

2.  Return Code Usage

2.1.  Return Code Categories

   The following categorizes return codes from gateways based on
   expected Call Agent behavior.

   Category normal: These return codes are used in normal operation and
      do not represent error conditions.

   Category none (specific errors requiring specific action): A return
      code associated with a specific situation in the gateway that will
      invoke a corresponding specific Call Agent behavior.  As such,
      these return codes are not categorized into a common behavioral
      category.

   Category "Service Failure": A category in which the endpoint is
      either out-of-service or the treatment by the Call Agent is
      expected to be the same as for an out-of-service endpoint.

Foster & Sivachelvan         Informational                      [Page 2]
Show full document text