From my reading Squid Proxy is the probably the way to go. Although I'm not sure how you'd go throttling by user, group etc. There is also a Webmin Squid module so that should make it pretty easy to configure.
apt-get update
apt-get install squid webmin-squid
A quick google found this, which looks like it could be helpful. It's pretty old (2001) so you may find that some aspects are no longer relevant but at a quick glance it looks like it could still be a useful resource. There's probably more recent documentation about. Also you may find some assistance over on the Ubuntu forums (TKL is Ubuntu 8.04 under the hood).
Please note this is not a definative answer, someone with more experience may have a better answer.
PS also please post back with your findings as no doubt others may be interested in this.
Yes but AFAIK you will need to use a proxy service
From my reading Squid Proxy is the probably the way to go. Although I'm not sure how you'd go throttling by user, group etc. There is also a Webmin Squid module so that should make it pretty easy to configure.
A quick google found this, which looks like it could be helpful. It's pretty old (2001) so you may find that some aspects are no longer relevant but at a quick glance it looks like it could still be a useful resource. There's probably more recent documentation about. Also you may find some assistance over on the Ubuntu forums (TKL is Ubuntu 8.04 under the hood).
Please note this is not a definative answer, someone with more experience may have a better answer.
PS also please post back with your findings as no doubt others may be interested in this.