Question: What triggers the increment of the SC.SuccEmgSess measurement at the E-CSCF in an IMS network?
Option 1: Transmission by the E-CSCF of a SIP_200_OK response message for an emergency session setup (excluding SIP_REGISTER)
Option 2: Receipt by the E-CSCF of a SIP initial request message for a non-emergency session
Option 3: Failure of a SIP REGISTER attempt in an emergency context
Option 4: Completion of a successful call setup in the circuit-switched domain
Explanation: The SC.SuccEmgSess measurement counts successful emergency session procedures at the E-CSCF. This measurement is incremented upon the transmission of a SIP_200_OK response message by the E-CSCF for an emergency session setup, excluding SIP_REGISTER messages, indicating a successfully established emergency session.