The question about how you intend to measure the internet traffic. I will suggest a couple of options since I do not know your specific target scenario.
One decent internet monitoring tool is Snort (http://snort.org). It provides nice intrusion detection and can monitor the traffic hitting the internet quite nicely. Snort is great for intrussion detection but it is not so much a connectivity tool as it is a security tool. So this might not be the perfect tool for you.
Another good application that does this is MRTG...
MRTG is an excellent program that for stuff like monitoring your routers, switches etc. It is free and it has the ability to monitor a great many things. It will connect to the SNMP port of your router and you should be able to get all kinds of useful data about your connection at that point.
Now if you are trying to monitor your internet connection to see who you are talking to, you can always use the "Netstat" command from the command line or you can use TCPView from sysinternals to show you visually what your system is talking to over the wire.