With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
pbxCompletedMWICommands
pbx Completed MWI Commands
1.3.6.1.4.1.7505.1.1.10
The number of commands to set or clear a Message Waiting Indicator which have been successfully sent to the PBX. If the DPA is not operating in hybrid mode, this value will always be zero.
Back to CALISTA-DPA-MIB MIB page.
IPHost Network monitor allows you to monitor pbxCompletedMWICommands on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.