With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cdxCmCpeIfIndex
Cisco DOCSIS Cable Modem Cpe If Index
1.3.6.1.4.1.9.9.116.1.3.1.1.4
The CMTS cable MAC interface index (ifType of docsCableMaclayer(127)) that cable modem or Customer Premises Equipment connects to. Use cdxCmCpeIfIndex and cdxCmCpeCmtsServiceId to identify an entry in docsIfCmtsServiceTable.
Back to CISCO-DOCS-EXT-MIB MIB page.
IPHost Network monitor allows you to monitor cdxCmCpeIfIndex on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.