I am looking for a program that I can use to monitor Wi-Fi users on my network. Specifically, I want to monitor the Wi-Fi data usage of a specific smartphone user from my desktop computer (which has NetWorx installed). If there is the ability to keep a running tabulation of that usage, so much the better.
Reading the description of NetWorx however, it seems that it either must be installed on that smartphone as well, which is impractical in this case, or as the description states, "If your router supports so-called SNMP or UPnP protocol, you can monitor all traffic via your router. This however will not give you a per-device usage breakdown...". The router in this case is a Cisco DPC 3941T, which does support UPnP.
So, since I cannot get "per-device usage" with NetWorx, is there another way to that smartphone's usage with one of your programs? And if so, how do I do it?
Unfortunately monitoring a specific WiFi device from a desktop is computer is technically impossible. The reason is that the device communicates with the router directly, and your computer will not see or even know about it.
The only way to do this is to monitor the device on the router. This may or may not be possible, as the router itself must support such monitoring. Some top-end routers have per-device usage records, others can be flashed with custom firmware, but that's not a trivial task, and usually not something a regular user can do.