With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
frxNetChInactive
Cisco 90i Net Current Hour Inactive
1.3.6.1.4.1.1570.1.5.1.1.9
Number of times network Annex-D signaling channel was declared inactive.
Back to CISCO-90-MIB MIB page.
IPHost Network monitor allows you to monitor frxNetChInactive 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.