The present document defines the Stage 2 description for the Local Call Local Switch feature. Local Call Local Switch may be implemented in both BICC based CS core networks as defined in TS 23.205 and SIP-I based CS core networks as defined in TS 23.231, with a GSM/EDGE Radio Access Network supporting either TDM based or IP based A interface. This stage 2 shall cover the information flows between the GMSC server, MSC server and media gateways that are required to support Local Call Local Switching highlighting the specific requirements in addition to those defined for BICC based CS core networks TS 23.205 and SIP-I based CS core networks TS 23.231. Note that nothing in the present document shall preclude an implementation of a combined MSC Server and MGW. The present document shall show the CS core network termination of the A interface, and the information flows between the BSS and the MSC server, in order to cover the information flow stimulus to the core network and describe the interaction with the supplementary and value added services and capabilities. The present document specifies functions, procedures and information which apply to GERAN Iu mode. However, functionality related to GERAN Iu mode is neither maintained nor enhanced.

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

• References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.