[Codel] Worst case conditions - large RTT

Dave Taht dave.taht at gmail.com
Wed May 9 16:41:04 EDT 2012


On Wed, May 9, 2012 at 1:36 PM, Simon Barber <simon at superduper.net> wrote:
> Codel assesses the minimum delay over a fixed time period (the interval) -
> what happens when the interval is much smaller that the RTT. For example a
> tcp stream is experiencing a 2 second RTT (perhaps due to bufferbloat at
> some point), yet the interval is 100ms. The TCP implementation is a poor one
> that will ACK a window at a time. Here codel will drop excessively, and
> cause low throughput?
>

You are doing a great job of asking good questions.

I would hope we could get some more people lined up to answer them,
armed with sims and real hardware. Volunteers for each problem would
be helpful.

Me, I'd like very much to get some data back on the variable bandwidth
wireless scenario! Except that cerowrt's too broken at the moment to
use and I'm trying to fix that.

The latest netem does ECN, btw. And ns3 has a decent minstrel model.
(hint, hint)

> Simon
> _______________________________________________
> Codel mailing list
> Codel at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/codel



-- 
Dave Täht
SKYPE: davetaht
US Tel: 1-239-829-5608
http://www.bufferbloat.net



More information about the Codel mailing list