R6. IMS Registration signalling flow —
Network-initiated deregistration event occuring in the HSS
R6-4b. SIP 200 OK response:
between S-CSCF1 and HSS
(11 of 11)
After receiving the 200 (OK) response from P-CSCF1, S-CSCF1 sends Cx-Deregister Resp to the HSS.