Blocking internet traffic

[RC Da Kookee]

My friend is having limited internet bandwidth, 5 GB per month only.
Each GB over is kinda expensive but he's willing to go up to 12 GB top and when that mark is reached - to completely block internet access for the rest of that active month.

First of all I thought vnstat is the right thing but it can only slow down overall bandwidth speed while not fully stop it.
Is there any other script, daemon or such to achieve this stuff?

Thanks

[excollier]

You should be able to set limits, or warnings, in the router set up.
And some willpower.

[RC Da Kookee]

It's 3G modem so no luck there as with standard router.
I'm afraid that willpower is flat zero in his case so he's looking for something radical

[excollier]

Hide the modem for a couple of weeks

[DrHu]

First thought: what does the ISP offer for monitoring his usage up to the limit
--perhaps they have a notification option to let him know he is near exceeing his 5GB limit

Then there are a whole collection of tools to check, seeing which one or similar ones will provide that data
http://www.ubuntugeek.com/bandwidth-monitoring-tools-for-linux.html
http://bandwidthd.sourceforge.net/
--a kinda good looking gui tool, something like that may be of interest to your user..

http://ipband.sourceforge.net/
--or a kinda logger tool

A columnist..howto watch traffic thresholds..
http://www.linuxpronews.com/how-to-monitor-your-linux-network-bandwidth-usage-2009-01
http://www.linux-magazine.com/Online/Blogs/Productivity-Sauce/Monitor-Bandwidth-Usage-with-vnStat
--a slight more detailed explanation of it (vnstat)
--so he is using vnstat to collect usage stats over time..does/wouldn't that help ? (even though you looked at it already..)

If discipline is rally a problem for the user, not much will help with that. I be asking the ISP for some help with the problem of going over the limit he setting of using/geting 5GB of traffic before costs shoot up.
--maybel they'l listen.