[87450] in North American Network Operators' Group
Re: The Qos PipeDream [Was: RE: Two Tiered Internet]
daemon@ATHENA.MIT.EDU (Joe Maimon)
Sun Dec 18 14:29:03 2005
Date: Sun, 18 Dec 2005 14:28:31 -0500
From: Joe Maimon <jmaimon@ttec.com>
To: Chris Woodfield <rekoil@semihuman.com>
Cc: Michael.Dillon@btradianz.com, nanog@merit.edu
In-Reply-To: <F8524508-35CF-457F-912B-766D2B8E7B0C@semihuman.com>
Errors-To: owner-nanog@merit.edu
Chris Woodfield wrote:
>
> One thing to note here is that while VoIP flows are low volume on a
> bits-per-second basis, they push substantially more packets per kilobit
> than other traffic types - as much as 50pps per 82Kbps flow. And I have
> seen cases of older line cards approaching their pps limits when
> handling large numbers of VoIP flows even though there's plenty of
> throughput headroom. That's not something LLQ or priority queueing are
> going to be able to help you mitigate at all.
>
> -C
In that vein, and not quite on this topic, it would be real nice if voip
applications made an effort to stop abusing networks with unneccessarily
large pps.
Something about intelligent edges? The payload length of voip
applications often has a lot to do with rtt. Adapting payload length to
the actuall average rtt could have a positive effect on pps throughput.
