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From: Baptiste Jonglez <baptiste.jonglez@ens-lyon.fr>
To: Mikael Abrahamsson <swmike@swm.pp.se>
Cc: bloat@lists.bufferbloat.net, babel-users@lists.alioth.debian.org,
	Juliusz Chroboczek <jch@pps.univ-paris-diderot.fr>
Subject: Re: [Bloat] [Babel-users] RTT stability inside a GRE tunnel
Date: Tue, 2 Jul 2013 13:08:38 +0200	[thread overview]
Message-ID: <20130702110838.GD24656@ens-lyon.fr> (raw)
In-Reply-To: <alpine.DEB.2.00.1307020640190.10894@uplift.swm.pp.se>

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On Tue, Jul 02, 2013 at 06:48:14AM +0200, Mikael Abrahamsson wrote:
> On Tue, 2 Jul 2013, Juliusz Chroboczek wrote:
> 
> >Anybody seen anything similar?
> 
> I don't know if this is the cause, but older gear from Extreme
> Networks (their end-of-90ties and beginning of 2000s), will do ICMP
> in slow-path when routing (even packets going through the device) and
> "everything else" in fast-path. This could cause latency spikes and
> PDV approximately similar to what's seen in the picture.

This looks like a plausible explanation, thanks.  They may not be the
only router make to exhibit this behaviour.

Is there a reason for this slow-path routing of ICMP?  I've seen
routers applying some kind of rate-limiting to ICMP packets, but as
far as I know, it's only limited to ICMP packets originating from the
router.

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  reply	other threads:[~2013-07-02 11:08 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20130701164607.GB12090@ens-lyon.fr>
2013-07-01 23:58 ` [Bloat] Fwd: " Juliusz Chroboczek
2013-07-02  0:02 ` [Bloat] " Juliusz Chroboczek
2013-07-02  4:48   ` Mikael Abrahamsson
2013-07-02 11:08     ` Baptiste Jonglez [this message]
2013-07-02 11:27       ` Mikael Abrahamsson

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