With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
ccmCTIDeviceTimeLastRegistered
Cisco Call Manager CTI Device Time Last Registered
1.3.6.1.4.1.9.9.156.1.8.1.1.12
The time the CTI Device last registered with the call manager.
Back to CISCO-CCM-MIB MIB page.
IPHost Network monitor allows you to monitor ccmCTIDeviceTimeLastRegistered 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.