IMS Registration signalling flow —
User not registered
R1-1e. SIP REGISTER request:
from I-CSCF1 to S-CSCF1
(6 of 22)
I-CSCF1 does not modify the Path header.
: This header contains information from UE1.
: S-CSCF1 stores the contents of the Path header and uses the URI for routing mobile terminated requests.