R2. IMS Registration signalling flow —
Re-registration – User currently registered
R2-2b. SIP 200 OK response:
from I-CSCF1 to P-CSCF1
(9 of 10)
: P-CSCF1 saves the value of the Service-Route header and associates it with UE1. P-CSCF1 then forwards 200 (OK) response from I-CSCF1 to UE1 indicating that the registration was successful.