Question: When a SIP Core (implemented by an IMS core network) receives a SIP request with a Resource-Priority header for an MCPTT session, what information does the P-CSCF provide to the PCRF to set corresponding PCC rules?
Option 1: Reservation-Priority AVP and MCPTT-Identifier AVP in the AA-Request command
Option 2: Priority-Sharing-Indicator AVP alone within the Media-Component-Description AVP
Option 3: AF-Application-Identifier AVP only, specific to MCPTT
Option 4: Both Reservation-Priority AVP and Priority-Sharing-Indicator AVP in separate AA-Requests
Explanation: According to the handling of MCPTT priority calls within the IMS core network, when the P-CSCF receives a SIP request with a Resource-Priority header for an MCPTT session, it must provide both the Reservation-Priority AVP (to adjust the priority) and the MCPTT-Identifier AVP (to identify the MCPTT service) in the AA-Request command. This allows the PCRF to set the appropriate PCC rules based on the prioritized MCPTT service.