Question: Under what circumstances may a P-CSCF (Proxy-Call/Session Control Function) send a HELLO request message to a UE (User Equipment) in the context of TLS (Transport Layer Security) session management?
Option 1: When initiating a new IP-based service connection
Option 2: Periodically, as part of routine network maintenance
Option 3: At any time, to trigger a TLS session renegotiation based on local policies
Option 4: Only in response to a UE's request for security protocol update
Explanation: This is correct because, according to telecom security standards, a P-CSCF has the flexibility to initiate a TLS session renegotiation at its discretion, driven by local security policies, allowing for dynamic adjustment of security parameters without requiring a specific prompt from the UE or being limited to particular network events.