From: David Lang <david@lang.hm>
To: Neil Davies <neil.davies@pnsol.com>
Cc: Jonathan Morton <chromatix99@gmail.com>,
bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] Detecting bufferbloat from outside a node
Date: Mon, 4 May 2015 10:39:22 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.02.1505041027080.2656@nftneq.ynat.uz> (raw)
In-Reply-To: <D0A9B190-14D1-4FFE-9AFC-BA36777AD3C7@pnsol.com>
[-- Attachment #1: Type: TEXT/PLAIN, Size: 1452 bytes --]
On Mon, 4 May 2015, Neil Davies wrote:
> Jonathan
>
> We see the problem as the difference between averages and instantaneous.
>
> Network media is never “average” used - it is either “in-use” or “idle” - what
> we were seeing (and it was not an ISP but the core of a public service network
> here in the UK) was that delay can be “high” even when the loading is “low”
> (in the particular 5minute period the actual offered traffic was <0.01% of the
> capacity) - it was that the path under examination happened to be the
> constraining factor for a bulk transfer - the induced delay was high enough to
> place at risk other real-time applications (as defined by the public service
> network’s users).
If you are doing a single bulk data transfer through a link and are at a small
percentage of the capacity but yet experiencing long delays, then something is
wrong.
either you have a small window size so that you aren't actually using the full
capacity of the link, you are in the ramp-up time, or you have something
dropping packets preventing you from getting up to full speed. But all of this
should be affecting the sending machine and the speed that it is generating
packets.
the device should not be buffering anything noticable if it's at such a small
percentage of utilization. check to see if there is QoS configuration on the
system that may be slowing down this traffic (and therefor causing it to queue
up)
David Lang
next prev parent reply other threads:[~2015-05-04 17:39 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-27 9:48 Paolo Valente
2015-04-27 9:54 ` Neil Davies
2015-04-27 10:45 ` Toke Høiland-Jørgensen
2015-04-27 10:57 ` Neil Davies
2015-04-27 14:22 ` Toke Høiland-Jørgensen
2015-04-27 20:27 ` Neil Davies
2015-04-27 15:51 ` Toke Høiland-Jørgensen
2015-04-27 20:38 ` Neil Davies
2015-04-27 21:37 ` Toke Høiland-Jørgensen
2015-04-28 7:14 ` Neil Davies
2015-04-27 11:54 ` Paolo Valente
2015-04-27 15:25 ` Jonathan Morton
2015-04-27 20:30 ` Neil Davies
2015-04-27 23:11 ` Jonathan Morton
2015-04-28 7:17 ` Neil Davies
2015-04-28 9:58 ` Sebastian Moeller
2015-04-28 10:23 ` Neil Davies
2015-05-04 10:10 ` Paolo Valente
2015-05-04 10:21 ` Neil Davies
2015-05-04 10:28 ` Jonathan Morton
2015-05-04 10:41 ` Paolo Valente
2015-05-04 10:44 ` Neil Davies
2015-05-04 10:42 ` Neil Davies
2015-05-04 11:33 ` Jonathan Morton
2015-05-04 11:39 ` Neil Davies
2015-05-04 12:17 ` Jonathan Morton
2015-05-04 12:35 ` Neil Davies
2015-05-04 17:39 ` David Lang [this message]
2015-05-04 19:09 ` Jonathan Morton
2015-04-28 16:05 ` Rick Jones
2015-04-27 20:13 ` Neil Davies
2015-04-27 9:57 ` Toke Høiland-Jørgensen
2015-04-27 10:10 ` Paolo Valente
2015-04-27 10:19 ` Paolo Valente
2015-04-27 10:23 ` Toke Høiland-Jørgensen
2015-04-27 10:53 ` Paolo Valente
2015-04-27 20:39 ` David Lang
2015-05-04 10:31 ` Paolo Valente
2015-04-27 10:26 ` Neil Davies
2015-04-27 10:32 ` Toke Høiland-Jørgensen
2015-04-27 10:38 ` Neil Davies
2015-04-27 10:52 ` Toke Høiland-Jørgensen
2015-04-27 11:03 ` Neil Davies
2015-04-27 12:03 ` Toke Høiland-Jørgensen
2015-04-27 20:19 ` Neil Davies
2015-05-19 21:23 ` Alan Jenkins
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