With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
alL2tpStatsSessionCallSerialNumber
ALTIGA L2tp Statistics Session Call Serial Number
1.3.6.1.4.1.3076.2.1.2.16.3.1.9
This object contains the serial number that has been assigned to this session.
Back to ALTIGA-L2TP-STATS-MIB MIB page.
IPHost Network monitor allows you to monitor alL2tpStatsSessionCallSerialNumber 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.