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Re: [tcpm] Congestion Window Validation

Tim Wicinski <tjw.ietf@gmail.com> Fri, 31 January 2014 11:20 UTC

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Date: Fri, 31 Jan 2014 06:20:44 -0500
From: Tim Wicinski <tjw.ietf@gmail.com>
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Subject: Re: [tcpm] Congestion Window Validation
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I contacted Martin, who confirmed he is referring to version 04 of the 
document:
     http://datatracker.ietf.org/doc/draft-ietf-tcpm-newcwv/

Comments inline:

On 1/31/14, 4:54 AM, Martin Winbjörk wrote:
>
> Hello
>
> My name is Martin Winbjörk and I am a student at Luleå University of 
> Technology. I am currently writing my master thesis "TCP Optimized for 
> Wireless Access" at Ericsson in Sweden, Luleå. In the thesis I am 
> evaluating different TCP enhancements and Congestion Window Validation 
> is one of them.
>
> I have a question regarding section 4.4 on page 9 where it is stated 
> "A cwnd-limited sender uses the standard TCP method to increase cwnd 
> (i.e. a TCP sender that fully utilises the cwnd is permitted to 
> increase cwnd each received ACK)." I don't fully understand when this 
> scenario can occur in the non-validated phase?
>
> On the same page I found what appears to be two typos.
>
> "reducing the cwnd as defined in section 4.3.1" should be "reducing 
> the cwnd as defined in section 4.4.1"?
>
> "The resulting reduction of cwnd described in section 4.3.2 is 
> appropriate, since any accumulated path history is considered 
> unreliable" should be "The resulting reduction of cwnd described in 
> section 4.4.2 is appropriate, since any accumulated path history is 
> considered unreliable"?
>
I agree with Martin, it appears the sections were altered between 
draft-02 and draft-03 but the changes were not passed through the entire 
document.

Additionally, at the bottom of Page 12 has a similar mention to section 
4.3.2 which should be changed to 4.4.2

> I also have a request regarding an equation on page 11.
>
> May "cwnd = max(1/2*cwnd, IW)" have parentheses added around 1 / 2 for 
> added clarity?
>

I agree with his comments on the parentheses added around (1/2) in 
section 4.4.3, as this seems to be done elsewhere in the document as such.



> Regards
>
> Martin Winbjörk
>
>
>
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