With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
csCugIfEntry
Cisco ATM Switch Closed User Group If Entry
1.3.6.1.4.1.9.9.89.1.2.1
An entry in this table must be created in order to enable the screening of closed user group calls and enable the barring of transmission of CUG interlock codes across the interface. Closed user group calls are screened by looking up csCugTable.
Back to CISCO-ATM-SWITCH-CUG-MIB MIB page.
IPHost Network monitor allows you to monitor csCugIfEntry 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.