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

[Joe Touch <[e-mail]>]

Maybe it should have been for IW=3 too, but it didn't occur to me at the 
time.

The benefit is that had we used this mechanism then, we wouldn't be 
asking for a new IW now, though.

Joe

On 11/18/2010 1:11 PM, John Heffner wrote:
> Why is this mechanism required for IW=10 but not for IW=3?
>
>    -John
>
>
> On Thu, Nov 18, 2010 at 4:08 PM, Joe Touch<[e-mail]>  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'll be glad to write this up if people need a more concrete proposal.
>>
>> Joe
>>
>> On 11/18/2010 1:05 PM, Anantha Ramaiah (ananth) wrote:
>>>
>>> Why can't you do something like this :
>>>
>>> - If any one of the TCP connections egressing out of that interface
>>> (this can determined in TCP layer) is in the TCP retransmit state (or
>>> has experienced congestion in the past xxx secs/mins), then go back to a
>>> lower IW for new TCP connections which are using the same output
>>> interface..
>>>
>>> - When you want to start a connection, use the connection history (Joe's
>>> RFC)
>>>
>>> Well, there may be some gotchas of this scheme, but you can become
>>> conservative when there is some concrete information.
>>>
>>> Thanks,
>>> -Anantha
>>>>
>>>> To be more clear, here's the case:
>>>>
>>>>         start 1000 connections in a row.
>>>>
>>>>         during the first connection, lose some packets and do
>>>>         normal TCP backoff
>>>>
>>>>         so what do the other 999 connections start with?
>>>>         ans: 10 packets
>>>>
>>>> The point is that subsequent connections don't do anything different.
>>>> If
>>>> you have 1000 connections, you're sending a certain amount of data
>>>
>>> into
>>>>
>>>> the network without reacting. We're tripling that.
>>>>
>>>> That can easily cause congestion. At which point the *existing*
>>>> connections will backoff, but new connections keep making problems.
>>>>
>>>> Joe
>>>> _______________________________________________
>>>> tcpm mailing list
>>>> [e-mail]
>>>> https://www.ietf.org/mailman/listinfo/tcpm
>>
>> _______________________________________________
>> tcpm mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/tcpm
>>