With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
ccmGatewayRegFailReason
Cisco Call Manager Gateway Registration Fail Reason
1.3.6.1.4.1.9.9.156.1.3.1.1.17
The reason code associated with registration failed gateway.
Back to CISCO-CCM-MIB MIB page.
IPHost Network monitor allows you to monitor ccmGatewayRegFailReason 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.