[ale] iptables TOS (was: b'bye)

[Jim Popovitch]

On Tue, 2005-05-24 at 14:49 -0400, Christopher Fowler wrote:
> Now you confused me.  
> 
> 1.  What is TOS vs QoS?

QoS (Quality of Service) is an overall measurement/goal/ideal/etc.  

TOS (Type of Service) is an IETF standard (now replaced by DSCP) used to
classify packets.  TOS is part of the IP packet header.  Gorey stuff
here:
  http://www.aarnet.edu.au/engineering/networkdesign/qos/precedence.html

> 2.  I've seen other commands used instead of iptables
>     when doing QoS.

Yes, total QoS involves many things.  Usage, jitter, latency, packet
loss, even pure perception (CEO vs new-guy).  There are many
applications, some good, some bad, some free, some $$, none perfect. ;-)

> 3.  Is it possible to limit bandwidth from a specific internal IP 
>     address no matter the load.  Can I say that 192.168.1.5 can only 
>     have up to 5% of the bandwidth period.  No bursting based on load?

Not solely with iptables.  Doing this involves using iptables to
classify (identify) packets with a "tag", and then using something like
tc or routing software to control tagged packets. Google for "traffic
shaping", your sure to find much details.  Here are two good starting
points:

  http://www.tldp.org/HOWTO/Traffic-Control-HOWTO/

  http://lartc.org/

Warning:  Traffic Shaping (with or without Linux) folks are much more
opinionated than the root/non-root crowd. ;-)

-Jim P.