Question on Access Plans on Firewall (Kind of like an ISP)

[Peter Foley]

Heya all,

My Parents are deciding to get Transact as well, and my mother has asked me
to put together something that will be able to restrict my brother to only
using the Net during certain times of the day and also give him a MB Limit.

I am going to build them a firewall box but am completely mystified on how
to do the restrictions.  I know there must be a way to do it (quite a few
ISPs run off Linux).  Any pointers to software or Howtos?

I am still siffting through all the docs that I found on IPTables, would the
answers be in there?  So far I have not come across anything to suggest that
IPTables can do this.

If it helps there is a machine that is running LDAP and Samba.  So I have
user accounts setup already.

Also I would like to have the Firewall handle all the restrictions
(Naturally it can look to the other machine for info in the LDAP database)

Thanks in advance.

Peter