With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
dsgIfDownstreamEntry
dsg If Downstream Entry
An entry in the DSG Downstream Table. An entry in this table exists for each ifEntry with an ifType of docsCableDownstream(128).
Back to DSG-IF-MIB MIB page.
IPHost Network monitor allows you to monitor dsgIfDownstreamEntry 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.