The Gateway MSC server must interrogate the HLR of the required subscriber to obtain routing information for a call or a short message directed to that subscriber.
Signalling on this interface uses MAP (TS 29.002).
For CAMEL purposes, this interface is used as described in
TS 23.078. It is used e.g. at terminating calls to exchange routeing information, subscriber status, location information, subscription information, etc.
This reference point enables the MRFC to fetch and cache documents and resources from an Application Server and
to return data to an Application Server.
It enables media control protocol requests, responses and notifications to be sent between the
MRFC and an Application Server.