To monitor calls, go to Monitoring --> Calls monitor node.

The Calls Monitor tab allows you to monitor the status of active calls. You can see the company name; date/start time of the call; calling; called; connected; media and state of the call. 

See below for the possible stats for a user in the Calls Monitor:

Date/Start time	Shows the date and start time of the call.
Calling	Shows the calling party number.
Called	Shows the called party number.
Connected	Shows the name of the calling party gateway.
Media	Shows the connected media of calling party (e.g. phone, headset).
Rec.	Indicates whether the call is being recorded or not.You can enable the recording function from the routing rule.
State	Orange LED indicates that the phone is ringing. Red LED indicates that the call is active. Grey Led indicates that the call is either begining or ending.
Actions	By clicking on the diagnostic icon   you can go directly to the diagnostic section on the gateway page. You can close the call by clicking on close icon . You can search for details of the call by clicking on search icon .