With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
frxPortChInactive
Cisco 90i Port Current Hour Inactive
1.3.6.1.4.1.1570.1.5.2.1.4
Number of times the subscriber port Annex-D signaling channel was declared inactive
Back to CISCO-90-MIB MIB page.
IPHost Network monitor allows you to monitor frxPortChInactive 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.