[ previous ] [ next ] [ threads ]
 
 From:  Chris Hoy Poy <chrishp at dugeo dot com>
 To:  m0n0wall at lists dot m0n0 dot ch
 Cc:  Mark Ryan <markryan at cfl dot rr dot com>
 Subject:  Re: [m0n0wall] traffic shaper borrowing
 Date:  Tue, 24 Oct 2006 10:01:32 +0800
hello again ;)

You've got pipes and queues.

my understanding is this:

 Queues represent possible slices of a pipe. The shaper will try to allow each 
queue its *minimum* % bandwidth of a pipe, but the queue is allowed to use 
all of the pipe if its available.

But pipes represent a hard limit, to my knowledge, and wont borrow from other 
pipes. You need to do that allocation at the queue level. 

Rules then allocate actual traffic to each queue. 

so looking at your question again : if FTP is in the low priority queue and 
everything else is in the high priority queue, then FTP will use the maximum 
pipe speed, but will drop back down to its minimum when something else 
happens.

Note the one "semi" issue I have seen is where you allocate a pipe to be less 
then the bandwidth you have available - it seems to use a bucket system to 
allocate the pipe, so if you allocate a really small pipe (like 512kbit) and 
you actually have 2mbit of bandwidth there, the pipe will flood the bandwidth 
for 1/4 of the time available and the actual usage will be very jagged. That 
may not apply, but I've done it a few times without thinking and found the 
behaviour (though it makes sense when I think about it) at the time was a bit 
bizarre. There might be some way to change the interval that the traffic 
shaper uses? It seems to be set at like 5 or 10 seconds. Having smaller 
intervals would make the flow a bit smoother, I assume. 

does that make sense? ;) 

On Tuesday 24 October 2006 09:44, Mark Ryan wrote:
> I've been evaluating whether the m0n0wall traffic shaper will work for
> me and I have to say wow!  It seems very nice.
>
> I do have 1 question:
>
> Does the traffic shaper use borrowing?  Such as if i have 2 upload ques,
> ftp assigned to low priority que and everything else assigned to high
> prio que.  Will the ftp consume the maximum available pipe speed until
> something in the high prio ques needs it, then i would assume the ftp
> traffic would slow down until the bw is available again?
>
> Sorry for the cryptic question there.
>
> Mark
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: m0n0wall dash unsubscribe at lists dot m0n0 dot ch
> For additional commands, e-mail: m0n0wall dash help at lists dot m0n0 dot ch

-- 
Chris Hoy Poy
System Administrator
DownUnder GeoSolutions
http://www.dugeo.com