With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cIdslItucPerfInvalidIntervals
Cisco Idsl ITU-C Performance Invalid Intervals
1.3.6.1.4.1.9.9.154.1.6.1.10
The number of near-end performance data 15-minute intervals in the range from 0 to cSdslStucPerfValidIntervals for which no data is available. This object will typically be zero except in cases where the data for some intervals are not available (e.g., in proxy situations).
Back to CISCO-IDSL-LINE-MIB MIB page.
IPHost Network monitor allows you to monitor cIdslItucPerfInvalidIntervals 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.
