Tech-invite  3GPPspace  IETFspace
SIP ↠  Examples  Grammars  Presence ⇾  Main  Services  Transaction  Dialog  IMS 
TS 24.228 – §7.2.2 – §7.3.2 – §7.4.2   List   Prev   Next
Top   Up   Prev   Next
IMS S1 signalling flow - Session Initiation: Mobile origination and termination roaming, with different network operators - IMS S1-1e. SIP INVITE request (UE1 to UE2): from S-CSCF2 to P-CSCF2
  • S-CSCF2 remembers (from the registration procedure) the UE Contact address and the next hop CSCF for this UE.
  • Route: Built from the Path header stored at registration.
  • Via / Record-Route: S-CSCF2 adds itself.
  • P-Called-Party-ID: Includes the dialled URL with its parameters.