Free tools in Windows XP itself would be perfmon (Network, bytes sent, bytes received counters) logged to a file, and Ping -t (continuous) piped to a text file. It is quite neat to create a batch file, starting with Date and Time commands, then the Ping command to give you a timestamp.
It may be possible to terminate the ping after a set time, but I've never tried. If necessary, just add the stop time by hand.
Note that a continuous ping for a very extended time might trigger a paranoid response from the remote host firewall, so use with consideration!
Netstat might help you to see the data volumes transferred, so you might want to see what it can do.
SD