With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
adsl2PMLHist1DValidInterval
ADSL2 Performance Monitoring L Hist1 D Valid Interval
1.3.6.1.2.1.10.238.1.4.1.4.1.9
This variable indicates if the data for this interval is valid.
Back to ADSL2-LINE-MIB MIB page.
IPHost Network monitor allows you to monitor adsl2PMLHist1DValidInterval on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.