With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
callHistoryDisconnectText
call History Disconnect Text
1.3.6.1.2.1.10.21.1.4.3.1.7
ASCII text describing the reason for call termination. This object exists because it would be impossible for a management station to store all possible cause values for all types of interfaces. It should be used only if a management station is unable to decode the value of dialCtlPeerStatsLastDisconnectCause.
Back to DIAL-CONTROL-MIB MIB page.
IPHost Network monitor allows you to monitor callHistoryDisconnectText on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.
