With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cvpdnSessionAttrModemCallStartTime
cvpdn Session Attr Modem Call Start Time
1.3.6.1.4.1.9.10.24.1.3.2.1.18
The start time of the current modem call. Only a session with a device of type 'asyncInternalModem' will have a valid value for this object; otherwise, it is not instantiated.
Back to CISCO-VPDN-MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor cvpdnSessionAttrModemCallStartTime on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.