With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
capTotalSessions
Cisco Admission Policy Total Sessions
1.3.6.1.4.1.9.9.653.1.1.1
This object indicates the total numbers of sessions created in the device since the last system reset.
Back to CISCO-ADMISSION-POLICY-MIB MIB page.
IPHost Network monitor allows you to monitor capTotalSessions on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.