With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
isdnMibBearerGroup
isdn Mib Bearer Group
1.3.6.1.2.1.10.20.3.2.2
A collection of objects required for ISDN Bearer channel control and statistics.
Back to ISDN-MIB MIB page.
IPHost Network monitor allows you to monitor isdnMibBearerGroup on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.