Media Gateway Control Protocol (MGCP) Version 1.0

Abstract

This document is being published for the information of the community. It describes a protocol that is currently being deployed in a number of products. Implementers should be aware of RFC 3015, which was developed in the IETF Megaco Working Group and the ITU-T SG16 and which is considered by the IETF and ITU-T to be the standards-based (including reviewed security considerations) way to meet the needs that MGCP was designed to address. AbstractThis document describes an application programming interface and a corresponding protocol (MGCP) which is used between elements of a decomposed multimedia gateway. The decomposed multimedia gateway consists of a Call Agent, which contains the call control "intelligence", and a media gateway which contains the media functions, e.g., conversion from TDM voice to Voice over IP. Media gateways contain endpoints on which the Call Agent can create, modify and delete connections in order to establish and control media sessions with other multimedia endpoints. Also, the Call Agent can instruct the endpoints to detect certain events and generate signals. The endpoints automatically communicate changes in service state to the Call Agent. Furthermore, the Call Agent can audit endpoints as well as the connections on endpoints.

Media Gateway Control Protocol (MGCP) Return Code Usage

“…This section describes return codes in MGCP 1.0 [1] in terms of "situations" that may have triggered that return code and "categories" to which the return code belongs. The purpose is to provide developers additional guidelines for return code use.…”

“…If the final response that follows a provisional response contains an empty response acknowledgement parameter, a Response Acknowledgement is used to acknowledge the final response (section 3.5.6 of [1]). …”

“…A final response will be provided later, after the transaction has completed. Refer to section 3.5.6 of [1]. An example of this might be a CreateConnection command using RSVP, where the time to create the connection may be longer than usual because of the need to perform the network resource reservation.…”

“…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.…”

“…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.…”