When two subscribers A and B are currently in a MSC X. A belong to
PLMN-A and B belong to PLMN-B. Both A and B have made and received
calls while in the same MSC X just a moment ago. If A calls B, will
MSC-X routes the calls to GMSC of PLMN-B and then GMSC routes the call
back to MSC-X?
Since the subscriber B already registered in MSC-x and made calls and
received calls earlier, can't MSC-X figure out that the subscriber B is
in the same MSC and deliver the call without any network messaging with
HLR or routing to GMSC?