Re: [tcpm] poll for adoption of long connectivity disruptions draft

Joe Touch <touch@ISI.EDU> Tue, 08 September 2009 22:50 UTC

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Date: Tue, 08 Sep 2009 15:49:17 -0700
From: Joe Touch <touch@ISI.EDU>
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Subject: Re: [tcpm] poll for adoption of long connectivity disruptions draft
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Pasi Sarolahti wrote:
> * Section 4.2, algorithm: this is really a nit, but might want to
> clarify in step (5) that if ICMP DU contains non-TCP header it should be
> ignored, without affecting the algorithm (right?)

It's not clear whether that is a feature or a bug.

If you have TCP that's idle, and other packets from your host traverse a
path and generate ICMP DUs, your TCP could benefit from reacting. I
didn't see anything in 1122 that would prevent that.

- --

FWIW, this draft continues the erroneous assumption that ICMPs are sent
in a timely fashion. Routers aren't required to do this, and so the
sequence number inside an ICMP should never be used as critical
information. It'd be useful (if not important) to explain the impact of
this on the algorithm in the draft.

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