Media Gateway Controller (MGC) - Media Gateway (MGW) interface; Stage 3
The present document describes the protocol to be used on the Media Gateway Controller (MGC) – Media Gateway (MGW) interface. The Media Gateway Controllers covered in this specification are the MSC server and the GMSC server. The basis for this interface profile is the H.248.1 [10] protocol as specified in ITU-T. The usage of this protocol is described in 3GPP TS 23.205 [2] and 3GPP TS 29.205 [7] for BICC circuit switched core network, in 3GPP TS 23.231 [54] and 3GPP TS 29.231 [57] for SIP-I circuit switched core network.
This profile includes the support for the enhanced MSC server to provide access to IMS Centralised services as described in 3GPP TS 23.292 [59] and thus the procedures related to this interface are described in 3GPP TS 29.292 [60]. As a result the interworking with SIP and the associated MGW control procedures described in 3GPP TS 29.163[61] for the interworking between BICC/ISUP circuit switched core network and IP Multimedia core network are incorporated.
This specification describes the changes to H.248 which are needed to handle 3GPP specific traffic cases. This is done by using the H.248 standard extension mechanism. In addition certain aspects of the base protocol H.248 are not needed for this interface and thus excluded by this profile.