What is DOCSIS PNM about?
PNM is a proactive approach to cable operator plant maintenance
PNM uses cable modems and CMTS as test probes
PNM locates up- and downstrream impairments
In an ideal scenario PNM identifies impairments before they impact the customer
DOCSIS Proactive Network Maintenance (PNM) is a relatively well known DOCSIS feature based and built on DOCSIS pre-equalization. Pre-equaliztion is a feature available to DOCSIS cable modems invented with DOCSIS 1.1 standard and improved with DOCSIS 2.0 and DOCSIS 3.1. This feature set is based on equalizer taps available in the cable modem. Equalizer taps do delay RF frequencies. Each unit of delay is called a tap.
How does PNM work?
1. Frequent and continuous data collection from CMTS and modems via SNMP
2. Frequent monitoring of modems in target
3. Analysis of distortion signatures
4. Issue evaluation and classification
5. Calculations of distances to reflection points
6. Plot modems on a map — visual representations of known issues.
The Advantage of DOCSIS PNM?
Reduced truck rolls
Reduced support calls
Reduced modem replacements
PNM lowers maintenance costs by first identifying the presence of RF impairments but also determine if the impairment is in-home or outside plant. It associates MAC addresses with the affected cable modems and identifies them on a business its geo-location. Now technicians can be directed to the impairment location for troubleshooting. In general cable operators improve the quality of experience for the subscriber by ensuring quality of service offering. Cable operators can also catch intermittent issues by monitoring their systems without the expense of an expensive test hardware platform.