Tracking down unexplained data usage

I have recently installed NetWorx on my computer to try and identify unexplained data usage, which is being reported by my ISP. Unfortunately I am not technically savvy enough to understand the various settings in NetWorx.

I am running Windows 7 64. I have a Fritzbox 7272 router. My desktop computer is connected to the router by ethernet cable, and my Western Digital media player is connected to the router via wifi. I stream movies from my computer hard drive to my WDTV media player, but the media player does not play any media from the internet. So, at least as far as I can understand it, my media player should not be using any data measurable by my ISP, other than checking for software updates etc. It should not be using the 100 MB per hour which my ISP is reporting, which I cannot explain.

Could someone please tell me if the setting "Monitor my router rather than this computer", will measure the local network data that streams from my desktop to my media player, via my wifi connection? (i.e. the data that should not be included by my ISP).

If use the setting "Ignore local traffic within the LAN", presumably this will only measure data coming to and from my desktop via the internet, and not pick up any unexplained internet traffic which my media player might be causing. Is that correct?

If the above is the case, is there any way to measure the data traffic between my WDTV media player and the internet, given that it is not possible to install any software on it directly?

In my efforts to identify where the excess data is coming from, I have so far left my computer running for 24 hours with Wifi turned off, and connected as usual to the internet via ethernet cable. The data measured by NetWorx during this period matches what my ISP reports. So presumably the excess data is not coming from some rogue background application on my computer. Now that I have turned Wifi on again, I need to be sure that I understand the settings in NetWorx so that I can make sense of the readings it is providing me.

Any help will be very gratefully received.

The Monitor my router rather than this computer option records usage data directly on the router's Internet interface. These records include all devices connected to the router and should be the closest to what ISP reports. There a few issues with this method though:

• The router must support SNMP polling or certain features in its UPnP implementation.
• There is no break down by device, there is only a total figure of how much data was sent and received.
• The computer hosting NetWorx needs to be on 24/7 to keep polling the router for usage figures.

The Ignore local traffic within the LAN option records all usage data on your computer excluding any local communications. So, if you stream a movie from your computer to your smart TV, that will be considered local traffic and will be disregarded.

Unfortunately, in general there is no easy way to track how much data each device downloads in a typical home network. The reason behind this is that every device talks to the router independently and a regular application like NetWorx cannot access that data. Some more expensive routers provide per-device usage report in their web-interface, but vast majority do not.

In other words, what NetWorx does is:

• It can monitor how much data was sent and received by your router (subject to the router's support of certain features).
• It can monitor how much data was sent and received by your PC (wired and wireless).
• It cannot monitor other devices like smart TVs, gaming consoles, etc as those access the router directly.

If you absolutely need to monitor each device, there may be a way to change your router's firmware or buy a suitable router. I recommend checking this article that explains how it can be done.

Thanks, that's very helpful.