With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cvpdnSessionTotal
cvpdn Session Total
1.3.6.1.4.1.9.10.24.1.1.2
The total number of active users in all the active VPDN tunnels within this system.
Back to CISCO-VPDN-MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor cvpdnSessionTotal 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.