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From: Rick Jones <rick.jones2@hp.com>
To: leno soff <lnxuff@gmail.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	eric.dumazet@gmail.com, davem@davemloft.net
Subject: Re: How to accelerate tcp retransmition
Date: Tue, 24 Jan 2012 09:57:24 -0800	[thread overview]
Message-ID: <4F1EF104.1040107@hp.com> (raw)
In-Reply-To: <CAC=NXX2NLsChhuY5_Bv3HJ4fvnq7XpM7UksPS80uaZgGsJnfVw@mail.gmail.com>

On 01/24/2012 06:09 AM, leno soff wrote:
> On Tue, Jan 24, 2012 at 4:58 PM, leno soff<lnxuff@gmail.com>  wrote:
>> Hello everyone,
>>    I have a lot of client, say C1, C2, .. Cn, which route packets to
>> my servers through router R. But R will drop 70% - 90% _ non-SYN _
>> packets from clients to Server.

I think you should address that first - why does the router drop 70 to 
905 of the non-SYN segments it receives.  At first blush that sounds 
like a classic case of massive over-subscription, and any attempt to 
accelerate the retransmissions seems destined to trigger congestive 
collapse.

As a side issue, if the router is dropping 70 to 90% of the non-SYN 
segments, why is it not also dropping 70 to 90% of the SYN segments?

Also, I'm reasonably confident that an actual keepalive probe would not 
(or at least should not?) be considered in the three duplicate ACK 
heuristic.

rick jones

      reply	other threads:[~2012-01-24 17:57 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-24  8:58 How to accelerate tcp retransmition leno soff
2012-01-24 14:09 ` leno soff
2012-01-24 17:57   ` Rick Jones [this message]

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