Network Monitoring Tools?

[preytogod]

So as most of you know having bandwidth caps on your internet sucks. And having to share this bandwidth sucks even more. So I was wondering if anyone knows of a good network monitoring tool that watches and records how much each individual device is using - and possibly what they are using it on.
I am looking for a tool similar to languardian-Network Bandwidth Monitoring Solutions | NetFort Technologies-.
Preferably not a program you install on each computer - because there are a mix of devices using the internet.
It has to be free - if it isn't I might as well get languardian.
Every one is connecting through a wireless router that is connected to our internet modem/or router.
Wireless router is not compatible with a different firmware.
And yes it is secured with mac filtering and wpa2-psk.
If I need a server - then I have an old computer that I can work with to do that.
I also have a switch.

I would appreciate any help I can get.
Hope I didn't make this too long.
Thanks

[Kgury]

Are you trying to find out what hardware is bottle-necking your connection?

[preytogod]

I am on wildblue and they have a bandwidth limit - a cap on the amount of data allowed to be downloaded in a period. So I am trying to monitor the amount of data each device (i.e.- computer, ipod, and tablet) is using. They do provide a way to monitor the amount of data you used in total ,but it doesn't show each individual device's data usage.

P.S. Thanks for posting something even though it was a question!

[amd91]

Sometimes Wireless router has a bandwidth monitoring..like Netgear.