Support for multiple conference factory PSI

3GPP TS 23.003 lists three conference factory PSI formats that could be required in a network:

where <domain>, <MCC> and <MNC> correspond to properties of the platform.

The relevant sections of 3GPP TS 23.003 include:

The values that parameterise standard conference PSIs (such as MCC/MNC) are in the configuration for the PLMN ID Analyser Component and the configuration profile defined in Sentinel SIP.

The set of standard conference factory PSIs supported is derived from the Sentinel SIP Configuration profile and the PLMN ID Analyser Component. For example, if HomeNetworkIds is set to example.com and the configured home PLMN IDs are (254,01) and (254,17), the set of standard conference factory PSIs is:

If no matching standard conference factory PSI is found, then check all alias conference factory PSI.

The MMTelConf configuration profile (from the MMTelCONFConfigProfileTable table) defines a property AliasConferenceFactoryPSI. This property is a set of Strings that identify non-standard conference factory PSI that should be recognised by the platform. Each String must be a valid SIP URI or Tel URL.

Each entry in the alias conference factory PSI set is a String that is a constant or parameterised by:

For example, if HomeNetworkIds is set to example.com and the configured home PLMN IDs are (254,01) and (254,17),

and …​

then the supported alias conference factory PSIs are:

If no matches are found, then this trigger is not relevant for MMTel Conferencing. The feature will end, and control will return to the Sentinel runtime.