After upgrading my internet connection from 512kb/s to 1.5Mb/s (and 14GB on-peek/month to 20GB on-peek/month), our download usage has gone through the roof. I have made special effort to be careful with downloads and to not download much, but our usage will just not go down. Before we would download approx 600 Mb per day, and it has skyrocketed to over 1 GB per day.
"As previously suggested, installing monitoring software would greatly help track the source of this problem. Although I have a feeling a lot of your problem is Youtube and other streaming video sites, my siblings are horrible for this as well. It doesn't seem like a lot, but 1 hour of viewing can easily rack up 150mb+ bandwidth on regular videos, not counting if someone is viewing HD videos. HD videos are much worse, more than likely 2 to 3 times the bandwidth per video.
Having an old speed of 512k would probably deter other residents from Youtubing because of constant pauses in the video makes it annoying to watch. The 1.5Mb/s jump would fix that, and I would assume a lot more streaming video is being watched.
If the Macbook was used, you may want to look into the applications installed, make sure no malicious software is running in the background gobbling up bandwidth as well."
"There are many websites that reload themselves, or parts of themselves at set intervals, and this can eat up bandwidth. noscript plugin (firefox) helps me keep websites from using my cpu and bandwidth senselessly"
"I would be inclined to generate your own usage reports for a month. If your usage reports do not match theres, have their technicians look into it. Dare them to hit you with the fee.
All the ISP's I worked with while I was living in Australia attempt to foist the buck off you. ""Oh, it's not our fault, but if you want us to check it, we will. But it will cost $$$ if you're wrong!"". The seed of doubt goes into the customer's mind, then the problem is dropped, everyone is happy - except the customer.
Get your facts and figures, do a little poking around on your network. Heck, unplug the computers and other devices, and see if you're still getting usage for a period. (Some ISP's will let you drill down on a per hour basis).
Bottom line: If you're sure the ISP is getting it wrong, and it's not being caused by you, don't be afraid to call them on their crap. Nine times out of ten, when the user says ""You've got a problem, here's the evidence to back it up"" the problem magically fixes itself, and you hear nothing about it - until it happens again.
"The suggestions so far are sound. A couple of other possibilities:
Some download sites have options, usually selected by the user but perhaps unknowingly (e.g. when it asks 'what is the speed of your connection?', on download volumes for audio/video streaming. With the higher bandwidth available could you, or other users, be using the same streams or other downloads, but at a higher quality/resolution/volume? Could the new Macbook be contributing to the increase? you don't say how long this increased usage has been going on for or whether the Macbook replaced another machine or is additional. Viewing in higher quality than a previous machine (as in 1.), providing additional user-initiated load, 'catching up' on patches and updates or just additional concurrent usage?
If the ISP provides day-by-day or hour-by-hour usage information perhaps you could try a period of time with no machines running and then several periods with one machine only but doing the normal work for that machine to see if you can identify whether the increase is on one of the machines rather than other(s)."
"There's a number of good monitoring suggestions already here. I just wanted to throw in that if you are running Windows machines you may have had some large MS updates / service packs come through, in which case the next month should be better again.
It could also just be the temptation of the higher speed, when everything goes a bit faster you more easily leave things running that you would otherwise turn off more rigorously. There is after-all a reason you went from 512 to 1.5, right? But the monitoring software should be able to help determine that."
