With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cvCallActiveDS0s
Cisco Voice Call Active DS0s
1.3.6.1.4.1.9.9.63.1.3.3
The current number of DS0 interfaces used for the active calls.
Back to CISCO-VOICE-DIAL-CONTROL-MIB MIB page.
IPHost Network monitor allows you to monitor cvCallActiveDS0s on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.