M4 Mobile Number Portability
From Kolmisoft Wiki
Using Mobile Number Portability (MNP) to route calls, The MNP database returns a Carrier Identification Parameter (CIP) for ported subscribers (this information is stored in the MNP database column set in Result field in settings page).
One or more codes together form a Carrier Group.
Carrier Group can be assigned to Termination Point, as part of the Mobile Number Portability routing algorithm to select the destination for MNP calls.
TP with Carrier Group is matched with the CIP Carrier Group. If a match is found TP is validated for this call. In other words - only selected TPs can serve MNP Numbers.