4.21 Support of Overlap Signalling

23.2283GPPIP Multimedia Subsystem (IMS)Release 18Stage 2TS

The support of overlap signalling consists of the functionality for conversion between overlap and en-bloc, as well as the functionality for digit collection.

The above mentioned functionalities may be implemented in different network nodes depending on the operator’s deployment strategy (e.g. AS, IBCF, MGCF).

NOTE 1: Support for overlap signalling in the IMS is an option limited to the interworking function located within the PSTN/ISDN networks that use overlap signalling.

NOTE 2: Digit collection limits the number of messages with incomplete number and to find another node that support overlap signalling.