This CoriantTypesEnableSwitch (default disabled) puts the Trail Trace Identifier Mismatch (TIM) function on a 10G WAN PHY client port framed as SONET into monitor-only mode, where mismatches are logged but do not trigger the more disruptive default TIM actions such as inserting AIS. An administrator enables monitor mode during a controlled migration or provisioning change, when trace strings are expected to be temporarily inconsistent and staff don't want that inconsistency to disrupt live traffic. For example, enabling TIM monitor mode on 10G WAN SONET while renumbering trace identifiers across a network lets staff see mismatch events in the log without each one triggering an AIS insertion and a resulting service-affecting alarm.