I’m currently managing a Cisco Communications Manager Server and a Cisco IOS Voice Gateway that is connected to the PST via several PRIs. The backhaul between CM and the VG is MGCP so for these commands to work in your environment you should have the same or similar. These likely wont work with a SIP environment.
show call active voice summary
Shows the number of active call legs.
show call active voice compact
Shows basic information about each call leg. Info provided is call id, time in seconds, VOIP or TELE leg and IP Phone IP Address.
show voice port summary
By including a voice port this command shows the Bearer Channels. Up means the Bearer Channel is active, dorm means it’s dormant.
show voice call
Displays if a bearer channel is in use and the channel’s state.
show voice call status
Shows some basic usage information including CallID, CID, Voice Port & Bearer Chanel, DSP, and Codec