With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cvpdnSessionAttrModemCallStartIndex
cvpdn Session Attr Modem Call Start Index
1.3.6.1.4.1.9.10.24.1.3.2.1.19
Arbitrary small integer to distinguish modem calls that occurred at the same time tick. Only session over device '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 cvpdnSessionAttrModemCallStartIndex on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.