With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
tn3270eTcpConnActivationTime
tn3270e Tcp Connection Activation Time
The value of the sysUpTime object the last time this TCP connection became active.
Back to TN3270E-MIB MIB page.
IPHost Network monitor allows you to monitor tn3270eTcpConnActivationTime 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.