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TS 24.228 – §7.2.3 – §7.3.6 – §7.4.4   List   Prev   Next
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IMS S4 signalling flow - Session Initiation: Mobile origination in home network, Termination in CS network - IMS S4-1b. SIP INVITE request (UE1 to UE2): from P-CSCF1 to S-CSCF1
  • S-CSCF#1 validates the service profile of this subscriber and evaluates the initial filter criterias. For this example, assume no Application Server involvement.
  • S-CSCF#1 performs an analysis of the destination address, and determines the destination is on the PSTN. S-CSCF forwards the INVITE request to the BGCF in the local network.