Question: In a WebRTC IMS client de-registration procedure, how do messages between the WebRTC IMS Client (WIC) and Serving-Call Session Control Function (S-CSCF) typically traverse in the core network?
Option 1: Directly between WIC and S-CSCF without any Proxy-CSCF involvement
Option 2: Via the P-CSCF (Proxy-CSCF) as per standard IMS procedures
Option 3: Via the eP-CSCF (emergency Proxy-CSCF), deviating from standard IMS routing for de-registration
Option 4: Through a combination of P-CSCF and I-CSCF (Interrogating-CSCF)
Explanation: In the context of WebRTC IMS client de-registration, messages between the WIC and S-CSCF traverse the eP-CSCF, deviating from standard IMS procedures. This adaptation ensures WebRTC clients' integration with IMS infrastructure while maintaining functional compatibility.