With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
snaLuRtmStateTime
sna Lu Rtm State Time
1.3.6.1.2.1.34.1.3.1.1.4
The timestamp (e.g., the Agent's sysUpTime value) when this session's RTM state (e.g., snaLuRtmState) changes value.
Back to SNA-NAU-MIB MIB page.
IPHost Network monitor allows you to monitor snaLuRtmStateTime 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.