Re: [tcpm] [Tmrg] Increasing the Initial Window - Notes

[Joe Touch <[e-mail]>]

Hi, Andrew,

On 11/18/2010 4:47 PM, Andrew Yourtchenko wrote:
>
>
> On Thu, 18 Nov 2010, Joe Touch wrote:
>
>> That's basically what I'm suggesting; it can easily be per subnet, per
>> interface, or per the entire machine as desired.
>>
>> The ultimate point is:
>>
>> - put something in the end node that notices if/when
>> it fails objectively, and fixes it
>>
>> - that same thing can allow the IW to increase
>> over time if there are no problems
>
> I think this is a very viable idea.
>
> However, I think there is a catch due to which it would need tweaking -
> there should be a signaling mechanism whereby a node on the
> "conservative" side of the connection would be able to signal the node
> on the "eager" side of the connection not to be too aggressive, in case
> the data flow is mostly from from "eager" to "conservative" side.

I think the rest of your argument boils down to how the client decides 
to aggregate it's idea of the best IW. That's up to the client to decide 
what it is willing to support - coarse or fine-grained.

An IW=10 as a static proposal is the coarsest possible; anything else we 
could do can't be any worse.

...
> If the above logic is right, then the peers during the 3whs should
> communicate their memorized values and pick up the minimum of theirs and
> the communicated by the peer.

Congestion isn't often bidirectional, so it's unlikely IMO that a peer 
would know what to suggest to its counterpart (if I understand your 
proposal). However, your suggestion is that there could be additional 
input if someone - anyone - knew 'better' what to do. That's fine - 
that's just an out-of-band hint to the algorithm.

Joe