[Technical] A "real" world problem for consideration

[Tisdall, Tim]

Hi Kevork,

Something that may suit your needs is ALTQ bandwidth shaping in OpenBSD's
Packet Filter (PF). You could very easilly divide the bandwidth into 4
queues of 25%, with any of them being able to 'borrow' bandwidth from
unused capacity in the other queues.

Any of the traffic passing through PF can be logged, so with appropriate
tools you should be able to use these for reporting. ntop may be a good
place to start looking as far as web based reporting tools go.

PF has also been ported to FreeBSD and NetBSD, and is now included in
their base installations. A kernel recompile may be needed support ALTQ in
these, but works out of the box in OpenBSD.

Cheers,

Tim Tisdall
____________________________________
Network Manager
The Mac.Robertson Girls' High School
Ph. (03) 98647740 Fax. (03) 98647777


-----Original Message-----
From: "Kevork Krozian" <Kroset at novell1.fhc.vic.edu.au>
To: <tech at edulists.com.au>
Date: Fri, 21 Apr 2006 11:53:05 +1000
Subject: [Technical] A "real" world problem for consideration

> Hi folks,
> 
>       In one of my other areas of interest I provide accommodation to
> overseas students around a major university. 
> One of these properties has an Optus cable modem internet link shared
> by 4 workstations through a switching router eg. Netgear or similar.
> 
>   Recently there has been a fair amount of tension between the students
> playing the blame game of accusing each other of slowing down the
> internet link or downloading more than their fair share ( 12GB link 
> midday to midnight, 3 GB each if all is fair   ---    20GB midnight to
> midday, 5 GB each if the daytime limit is not breached ) for the month.
>  
> 
>   The solution needs to be  two  ( maybe three ) fold:
> 
>                      1. Bandwidth management -- each user gets one
> quarter of available bandwidth
>                      2. Download usage management -- each user gets no
> more than one quarter of the limit for the month. User can check
> balance.
>                      3. Not be so expensive to setup and maintain ,
> that it makes the solution more expensive than setting up individual
> ADSL lines for each student.
> 
>    There is a linux solution --  between cable modema and switching
> router --  ( no need for anything higher than a PIII to do the job )
> using Squid to throttle bandwidth but this may be a hard limit eg.
> 50Kbps rather than " fetch current bandwidth, divide by four , update
> bandwidth allowed for each " .  Any gateway running a Windows platform
> solution will call for a high end machine and that alone makes any
> solution prohibitive.  Or , divide available bandwidth by number of
> users rather than by 4 as there may be bandwidth wasted if not everyone
> is on the network.
>    There is the issue of the rapidly fluctuating throughput measured
> eg. It is not unusual for a machine at home on a small network to
> record anything from 100Kbps to 400 Kbps during a short period
> depending what else is happening. 
> 
>    So, any thoughts out there from my esteemed colleagues ??
> 
> Regards
> 
> 
> 
> Kevork Krozian
> IT Manager , Forest Hill College
> k.krozian at fhc.vic.edu.au
> http://www.fhc.vic.edu.au
> Mobile: 0419 356 034
> 
> 
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