Question: What is the purpose of IKEv2 liveness check procedure in the context of keeping UE in CM-CONNECTED state in overlay network when accessing services via NWu?
Option 1: To establish a new PDU Session in underlay network.
Option 2: To ensure the signalling connection between UE and N3IWF is still valid when UE stays in CM-CONNECTED state.
Option 3: To trigger the release of UE from CM-CONNECTED state.
Option 4: To adjust the time interval of NAT-Traversal mechanisms.
Explanation: The IKEv2 liveness check procedure is used to ensure that the signalling connection between UE and N3IWF remains valid when UE stays in CM-CONNECTED state, thereby preventing unnecessary disconnections. This is an important consideration for maintaining a stable and reliable connection in overlay networks.