With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cagwPathCurrentSessions
Cisco's ASN Gateway Path Current Sessions
1.3.6.1.4.1.9.9.638.1.3.5.1.1.6
Number of Sessions over the path.
Back to CISCO-ASN-GATEWAY-MIB MIB page.
IPHost Network monitor allows you to monitor cagwPathCurrentSessions 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.