Check Communication Stats

Right Click On "Computer" (or "This PC") and click Manage

Open

Go to Device Manager and expand the Sangoma Communications Devices group. Right click on the Abstraction Driver and go to Properties

Open

For Analog Cards go to the "Analog Modules" tab. In here you will see "wanpipe10_if1" which is the interface. 

For PRI Cards go to the "Groups of channels" tab. In here you will see "wanpipe10_if1" which is the interface. 

Now that the wanpipe interface is known you can run the command "wanpipemon -i <interface> -c sc" from the command prompt to view the communication stats. The important state here along with all of the other counters is the "rx_over_errors" which shows if the driver is dropping data.