Is there correlation between return path noise and CPD?
Yes. Quite often, the root cause of the return path noise problem is also the same root cause of the CPD problem. That is why we highly recommend that if a node has a noise problem, to immediately fix all the CPD sources on that node. There is not necessarily a correlation between CPD severity and ingress. In many instances, Hunter has located relatively low-level CPD sources that turned out to be major ingress sources. This relationship between CPD and ingress is why we added the Xplor module to Hunter system. Here, charts are available that show the relationship between CPD and the carrier to noise ratio (CNR) of return channel. In the vast majority of cases there two metrics will track each other. In fact, our first recommendation is always to fix nodes where CPD and CNR alarms are consistent and indicated together.
