This reference point allows the Breakout Gateway Control Function to exchange session signalling message with the
Media Gateway Control Function for the purpose of interworking to the circuit switched networks, or for transit
This reference point allows the E-CSCF to request the LRF to validate the location information received from the
UE, to determine or query the LRF for routing information to emergency centres. Location information may be received from LRF and/or reference key to allow the PSAP to retrieve location at a later stage.
The MGCF interacts with the IM-MGW across the Mn reference point for controlling the functions of the IM-MGW, which are used to provide the connection between media
streams of an IP based transport network and bearer channels from a CS network.
The interface is used where it is wished to use the services of the S-CSCF to route to the MRF.
The interface is also used to support the establishment of a media control channel with the MRF, or between the MRF
and the MRB.