[87449] in North American Network Operators' Group
Re: The Qos PipeDream [Was: RE: Two Tiered Internet]
daemon@ATHENA.MIT.EDU (Chris Woodfield)
Sun Dec 18 14:09:20 2005
In-Reply-To: <OFF82600FC.F558D170-ON802570D9.00339D3B-802570D9.00341F3C@btradianz.com>
Cc: nanog@merit.edu
From: Chris Woodfield <rekoil@semihuman.com>
Date: Sun, 18 Dec 2005 14:08:48 -0500
To: Michael.Dillon@btradianz.com
Errors-To: owner-nanog@merit.edu
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
On Dec 16, 2005, at 4:29 AM, Michael.Dillon@btradianz.com wrote:
>
> A single VoIP call is a rather slim volume of packets compared
> to many other uses of the Internet. If a network doesn't have
> systemic jitter caused by layer 2 congestion, then one would
> expect VoIP to work fine on a modern network. Indeed, that is
> what Bill Woodcock reported a year or so ago in regard to
> INOC-DBA.
>
> --Michael Dillon
>
