Abstract: A data network comprises proxy-call session control functions (P-CSCFs) serving user equipments. Each P-CSCF can request resource reservation from an associated policy manager. A serving-call session control function receives a first call session setup message and determines a set of terminating user equipments associated with a terminating user identity of the setup message. It then transmits a call session initialization message to each identified terminating user equipment via an associated P-CSCF. This message includes a session identity indication and a forking indication which indicates if the first call session is a forked call session. The P-CSCFs and/or the policy managers then restrict the resource reservation for two or more user equipments having the same session identity and forking indications indicative of a forked call session setup to the resource requirement for only one of the user equipments. This may reduce resource usage for forked call sessions.

Abstract: A data network comprises proxy-call session control functions (P-CSCFs) serving user equipments. Each P-CSCF can request resource reservation from an associated policy manager. A serving-call session control function receives a first call session setup message and determines a set of terminating user equipments associated with a terminating user identity of the setup message. It then transmits a call session initialization message to each identified terminating user equipment via an associated P-CSCF. This message includes a session identity indication and a forking indication which indicates if the first call session is a forked call session. The P-CSCFs and/or the policy managers then restrict the resource reservation for two or more user equipments having the same session identity and forking indications indicative of a forked call session setup to the resource requirement for only one of the user equipments. This may reduce resource usage for forked call sessions.