With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
frxDSLDLCIEs
Cisco 90i DSLDLCI Errored Seconds
1.3.6.1.4.1.1570.1.6.1.1.17
Subscriber port Errored Seconds caused by illegal DLCI. Total number of seconds in which a frame that has a DLCI other than 16 to 23 (or 0) is received from this port.
Back to CISCO-90-MIB MIB page.
IPHost Network monitor allows you to monitor frxDSLDLCIEs 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.