For the purposes of this specification the following definitions apply:
The calling mobile subscriber.
The mobile subscriber originally called by the A subscriber.
The subscriber to whom the B subscriber has requested that calls be forwarded. The C subscriber may be fixed or mobile.
GSM Service Control Function (gsmSCF):
A functional entity that contains the CAMEL service logic to implement OSS. It interfaces with the gsmSSF and the HLR.
GSM Service Switching Function (gsmSSF):
A functional entity that interfaces the MSC/GMSC to the gsmSCF. The concept of the gsmSSF is derived from the IN gsmSSF, but uses different triggering mechanisms because of the nature of the mobile network.
Originating CAMEL Subscription Information (O-CSI):
The O-CSI identifies the subscriber as having originating CAMEL services.
Supplementary Service Notification CAMEL Subscription Information (SS-CSI):
The SS-CSI identifies the subscriber as having supplementary service invocation notification CAMEL services.
Terminating CAMEL Subscription Information (T-CSI):
The T-CSI identifies the subscriber as having terminating CAMEL services.
The serving MSC in the VPLMN.