From: Stef Coene <stef.coene@docum.org>
To: lartc@vger.kernel.org
Subject: Re: [LARTC] newbie - shaping a PSTN connection
Date: Wed, 10 Sep 2003 17:06:34 +0000 [thread overview]
Message-ID: <marc-lartc-106321618616482@msgid-missing> (raw)
In-Reply-To: <marc-lartc-106309566532407@msgid-missing>
On Wednesday 10 September 2003 02:43, Dancer Vesperman wrote:
> No worries. Why does it work?
> Every packet leaving an interface is up to MTU bytes in length. Let's
> say that a byte is ten bits (8+ 1start+1stop). So a 1500byte packet is
> 15000 bits. On a 28.8K connection, that means a 1500 byte packet takes
> 0.52 seconds to transmit. Assuming that the queueing discipline is FIFO
> (first-in-first out) and the queue length on the interface is, say, 10
> packets, a packet can take 10*0.52 seconds to get to the head of the
> queue. Plus transmission time, that's 5.2 (for queuing) +0.52 for
> transmission. Quite a delay.
>
> You may be able to do better by shortening the packet queue on the
> interface (ip link set ppp0 qlen 4) for example. Or attaching an SFQ
> queueing discipline (tc qdisc add dev ppp0 root handle 1: sfq perturb
> 10) - although for SFQ, I think you'd want a more substantive queue
> length.
You can use sfq with a shorter queue :
http://www.docum.org/stef.coene/qos/faq/cache/21.html
Stef
--
stef.coene@docum.org
"Using Linux as bandwidth manager"
http://www.docum.org/
#lartc @ irc.oftc.net
_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
next prev parent reply other threads:[~2003-09-10 17:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-09 8:21 [LARTC] newbie - shaping a PSTN connection Daniel Horth
2003-09-09 23:44 ` Damion de Soto
2003-09-10 0:43 ` Dancer Vesperman
2003-09-10 2:08 ` Dan Horth
2003-09-10 17:06 ` Stef Coene [this message]
2003-09-10 17:39 ` Stef Coene
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=marc-lartc-106321618616482@msgid-missing \
--to=stef.coene@docum.org \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.