With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
csbCallStatsNoMediaCount
Cisco Session Border Call Stats No Media Count
1.3.6.1.4.1.9.9.657.1.2.1.21
This object indicates the accumulated No media event count.
Back to CISCO-SESS-BORDER-CTRLR-CALL-STATS-MIB MIB page.
IPHost Network monitor allows you to monitor csbCallStatsNoMediaCount on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.