From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hagen Paul Pfeifer <hagen@jauu.net>
Subject: Re: [PATCH] =?UTF-8?Q?TCP=5FFAILFAST=3A=20a=20new=20socket=20opti?=  =?UTF-8?Q?on=20to=20timeout/abort=20a=20connection=20quicker?=
Date: Thu, 26 Aug 2010 09:42:36 +0200
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Cc: Lars Eggert <lars.eggert@nokia.com>, Jerry Chu <hkchu@google.com>,
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To: Arnd Hannemann <hannemann@nets.rwth-aachen.de>
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On Thu, 26 Aug 2010 09:12:24 +0200, Arnd Hannemann wrote:



>> USER_TIMEOUT is what is locally used for a connection (i.e., takes into

>> account what the remote peer advertised and what we'd like to use),

while

>> ADV_UTO is (only) what we'd like to use and are advertising.

>>

>> (Yes, we initially thought we could make the mechanism simpler, but

then

>> we started to think through all the corner cases...)

>>   

> 

> But from the application point of view it is enough to request a

> specific UTO

> as a socket option, (which will then get announced via ADV_UTO), right?

> Is there any reason, (besides local policy) to not abort the connection

> locally

> after the time the application specified via the above mentioned socket

> option?



The original USER_TIMEOUT (RFC 793) functionality boils down to Jerry's

TCP_FAILFAST patch. This _per see_ has no correlation with the ADV_UTO.

Likely that the ADV_UTO will update the USER_TIMEOUT too. I change my

position from day to day: artificially limit the mechanism and provide a

per see "clever" mechanism and keep both values coherent or provide all

freedom to the user.



Hagen