Linux Advanced Routing and Traffic Control list
 help / color / mirror / Atom feed
From: Andy Furniss <andy.furniss@dsl.pipex.com>
To: lartc@vger.kernel.org
Subject: Re: [LARTC] strange behaviour of qos
Date: Sat, 19 Mar 2005 11:53:37 +0000	[thread overview]
Message-ID: <423C12C1.4050408@dsl.pipex.com> (raw)
In-Reply-To: <42319DC2.80500@post.pl>

Ratel wrote:
> Ed Wildgoose wrote:
> 
>>
>>>
>>> any idea what might be wrong ?
>>
>>
>>
>>
>> Yep, something is queuing somewhere...
>>
>> Either your outbound setup allows too much outbound for the outbound 
>> connection (and if you use ADSL remember packets use more bandwidth 
>> than on ethernet).  Or you aren't throttling your inbound connection 
>> enough and queuing is occuring on the ISP end of your link
>>
>> Ed W
>>
> No, I really don't think so. The link itself is a 100%-CIR SDSL (for 
> LANof 300+ machines). I've
> set up ceil(up and down) to ~95% of real bandwidth.

That may be OK as long as CIR is at ip level not atm/aal5 also if you 
use older tc k means 1024.

In the case if ingress traffic - even if you set 95% and it really is 
95% then you need to back off a bit as the traffic has already been 
shaped by the link and at 95% you are only going to queue 5 packets for 
every hundred that pass - which means tcp bursts can fill and maybe drop 
from the buffer at the other end - hurting latency and if dropping - 
your bandwidth allocation.

> It seems that classes exceed maximum rates (ceils) defined for them.
> For example : p2p class has ceil of 2.5 mbits
> When p2p traffic is not allowed to pass through bandwidth usage varies 
> around 30%.
> Afrer allowing p2p to pass bandwidth usage quickly rises to nearly 100%.
> Is it possible to somehow isolate a class (as in cbq?) ?. In the 
> archives I've
> found something like this (let's say): '[...] rate 2500kbit ceil 
> 2500kbit'. This should
> produce something like isolated class , but for me it simply doesn't work.
> I'd be very grateful for any suggestions / ideas ...
> 
> Ratel
> 
> _______________________________________________
> LARTC mailing list
> LARTC@mailman.ds9a.nl
> http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
> 

_______________________________________________
LARTC mailing list
LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc

      parent reply	other threads:[~2005-03-19 11:53 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-03-11 13:31 [LARTC] strange behaviour of qos Ratel
2005-03-11 13:50 ` Ed Wildgoose
2005-03-12 16:58 ` Ratel
2005-03-19 11:53 ` Andy Furniss [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=423C12C1.4050408@dsl.pipex.com \
    --to=andy.furniss@dsl.pipex.com \
    --cc=lartc@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox