With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
ccmPhoneFailedTime
Cisco Call Manager Phone Failed Time
1.3.6.1.4.1.9.9.156.1.2.3.1.2
The time when the phone failed to register with the CallManager.
Back to CISCO-CCM-MIB MIB page.
IPHost Network monitor allows you to monitor ccmPhoneFailedTime on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.