Can I monitor, or control, the bandwidth used on my home network?

Let's start out with the good news. The ability to monitor your network and a lot of other items is built in to Windows XP, Windows 2000, and Windows NT in something called "Performance Monitor".

Run performance monitor by pressing Start, selecting Run, typing "perfmon" and pressing OK. You should get something that looks somewhat like this:

Right click in the empty chart area and select Add Counters... and you should see something like this:

The Performance Object dropdown lists several objects on your computer whose performance can be measured. The Processor, for example, is one. In that list select Network Interface, and the result looks like this:

The first list at the bottom of the dialog allows you to select which counters relating to that object you want to monitor. The second list allows you to select which object if there are more than one. In this example we'll select my "Intel Pro" network card on the right, and "Bytes Total/Sec" on the left. Press Add and Close and you'll see perfmon start to report the total bytes traversing the network card over time. After a little while in my example, it looks like this:

Perfmon is an incredibly powerful monitoring tool. There are lots of things available to monitor, and many display options. I encourage you to play around with it some.

Of special note is the Select Counters from Computer option in the Add Counters dialog above. Perfmon allows you to monitor the performance of another Windows XP, 2000 or NT computer remotely, across your LAN. This means, for example, if someone on your network is hogging all the bandwidth then you can monitor each machine remotely in real time to see just who that might be.

Monitoring is fairly easy. In addition to Perfmon there are certainly many third party applications that will allow you to do the same with different display and even triggered actions.

Control, on the other hand, is the bad news. True control of something shared like a DSL connection can be done, but it gets costly. It's typically performed by high end routers that allow you to specify, often in great detail, how the bandwidth should be allocated or prioritized. Unfortunately that's usually out of reach of the most home LANs.

In all honesty if this were my situation I'd just make sure the router was in arms-reach of my desk, and the cables well labeled. Then I'd physically unplug the connection for any computers who's users I felt needed to spend more time in the "real world".

But that's just me.