Data Traffic Counter

Hi all

Recently i got a laptop data modem for wireless internet connnection. The supplied software gives some indication of the per-session upload/download values, however this appears to be inaccurate and requires writing down the last traffic bytes everytime you disconnect.

Does anybody know of a(preferably freeware) program which keeps track of the data traffic over a period of e.g. one month?

The data contract comes with a certain amount of free data, over and above this usage every MB becomes uncomfortably expensive(out of bundle rate). Therefore i would like to keep an eye on the used downloaded bytes, without the hassles of writing down and adding up.

Thanks, The Hangwaiter