I've been playing various online games (Diablo 3, TF2, SC2, etc.) and I've found that I've been receiving massive lag spikes, often making the game unplayable. At first I attributed this to the other people in my house watching Youtube and generally hogging bandwidth, however I found today that even when nobody else is online that I'm still getting massive lag in my games. I already had this problem once before, I talked to my cable company about it and they swapped out our old modem/router for a brand new one (same model) and it apparently didn't do the trick. The thing is, this is just after an upgrade to a higher tier of service that my ISP offers, and before said upgrade, I wasn't experiencing any problems at all, I wouldn't even notice if anyone was using Youtube or anything.
I want a tool that is unobtrusive enough to let me play my games on a Mid 2010 MBP 15", and yet can monitor and record bandwidth and latency so that I have something that I can (hopefully) directly show my cable company and tell them that this isn't the quality of service that we're paying for (and I highly doubt that it's not our network, because these issues are persisting across all of the games I play). Any suggestions, preferably free, are highly appreciated.