Is it possible to make a plugin that records the traffic that we do with MSN messenger?
And if possible having the traffic divided by the different contacts, and in what the traffic was consumed.
For example (files sent / files received / webcam / audio / .... )

Like I have traffic limits, this will be good to have more control in what i can do.

Hope you understand the request, sorry for my poor english...

Well... It should indeed be possible to make a plugin that counts how much you sent/recieve when file transfering (I don't know if it is easy enough to split up the two, can't remember right now), and also to log how much you are text/traffic you are sending when sending messages, though this will not count all the protocol messages going on between messenger and the messenger server.... But what I just mentioned should be very easy... Then it should be possible to get some code that can see how much traffic goes through messenger total, there has to be some code at there that can help do this... ... I don't know if it is easy to count webcam and audio... But if someone wanted to do it, it would properly be possible making a standalone exe that acts as a proxy(or just some hock hooking).. then counts all data sent and recieved, and this program will of course have better chance of determing what data is what.. Webcam, Audio, and file transfers are handled by them selfes on their own ports, then just hook those connection and count the data being sent...
I don't think this will be made right now, but you might have a chance that someone will create it.. But I am saying that it is very possible, and somehow I really think that some people would appreciate this, since I know a few people that have traffic limits on their connection...

It'll be very easy to separate sent data and received data, as TCP connections like Messenger uses are by design full duplex. Think of it as a dual carriageway, and you'll get the idea.