Re: [aqm] TCP ACK Suppression

David Collier-Brown <davec-b@rogers.com> Wed, 07 October 2015 17:36 UTC

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To: aqm@ietf.org
From: David Collier-Brown <davec-b@rogers.com>
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Date: Wed, 7 Oct 2015 13:36:28 -0400
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Subject: Re: [aqm] TCP ACK Suppression
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On 07/10/15 01:19 PM, David Lang wrote:
> On Wed, 7 Oct 2015, Mikael Abrahamsson wrote:
>
>>> Oh, I hope that this is an exception. Such kind of optimizations may 
>>> cause a lot of trouble since a link layer device is interfering with 
>>> transport layer semantics. We all know that exactly these kinds of 
>>> interference eventually end up in problems with end-to-end 
>>> transparency and deployment of new protocol options. At least it 
>>> interferes with the ACK clocking expectation of some congestion 
>>> control algorithms...
>>
>> Personally, I think you're going to see more and more of this. There 
>> are mulitple shared access medium where you're allowed to send only 
>> part of the time, and it's someone else who tells you when you may send.
>
> it doesn't even require that someone else tells you when you may send. 
> It can just be waiting for an available transmit timeslot (Wifi for 
> example)
>
> collapsing multiple ACKs that are going to be sent at once is almost 
> always going to be a win.

I quite agree, but if there is a congestion control implementation "in 
the wild" that assumes it will get a stream of acks, that one's going to 
need some work (:-))

Anyone know if that's the case? The comment above suggest it may be...

--dave


-- 
David Collier-Brown,         | Always do right. This will gratify
System Programmer and Author | some people and astonish the rest
davecb@spamcop.net           |                      -- Mark Twain