Hung calls are calls that can be seen under the Current Active Calls but in reality, there is no active call. 

The switch relies on IP packet signaling to be updated about events that occur during a call. Occasionally when an IP packet is not received or can not be processed, the call state may become undetermined resulting in a “hung” call from the switch perspective. This does not mean that the call is hung, it just means that the switch is not aware of its state. Often, when this happens, the switch will terminate the call after a period of time.

This typically will only happen to on-net calls because offnet calls have refresh timers and most carriers will terminate a call after 15 minutes if there is no response from the phone.

Sometimes, however, the switch is not able to do so, and Support will need to do so from the back end. When this happens, please create a ticket with Support to terminate the call.