crossbow discuss - Jan 2009 - A question on bandwidth management

Hello:

I have a 10 Mbps line at office. I wish to split the bandwidth between
the regular office LAN and a set of computers that would benefit from
having 5 Mbps. Is it possible to do this with crossbow ?
 I believe it is, but would like to know what the crossbow developers recommend.

Actually, my larger question is this:
Assume that I do split the bandwidth, would this be just outgoing
bandwith (office to the internet) or incoming bandwidth too ?

Suppose a person from the office network were to start off an ISO
image down load, then would the 10 Mbps line be choked already ? Does
crossbow start to drop packets to enforce the 5 Mbps limit ?
I''m asking this because of what I''ve read here :
http://lartc.org/howto/lartc.qdisc.html#LARTC.QDISC.EXPLAIN

Hi,

Sriram Narayanan wrote:
> Hello:
> 
> I have a 10 Mbps line at office. I wish to split the bandwidth between
> the regular office LAN and a set of computers that would benefit from
> having 5 Mbps. Is it possible to do this with crossbow ?
>  I believe it is, but would like to know what the crossbow developers
recommend.
That is correct. We have a limitation that you can set the speed below
1.2 Mbps but in your case, you should be fine.
> Actually, my larger question is this:
> Assume that I do split the bandwidth, would this be just outgoing
> bandwith (office to the internet) or incoming bandwidth too ?
Currently its both. Whatever limit you configure will apply to
both inbound and outbound. So 5 Mbps limit means 5Mbps bi directional
i.e. each direction can go upto 5 Mbps.
> Suppose a person from the office network were to start off an ISO
> image down load, then would the 10 Mbps line be choked already ? Does
> crossbow start to drop packets to enforce the 5 Mbps limit ?
If the person is using TCP (which I assume he is), you will be fine
because the 5Mbps limit will cause TCP to rate limit itself. The
only time setting the limit is not useful is in case of UDP you
have no control over the originating traffic (coming from outside)
and they can choke the network before you get a chance to apply
the bandwidth limits.

Hope that helps.
Sunay