Re: [tcpm] alternate IW proposal

On Thu, 18 Nov 2010, Joe Touch wrote:

>
>
> On 11/18/2010 4:55 PM, Nandita Dukkipati wrote:
> ...
>> Fortunately, we don't have to speculate on the impact of delay on user
>> behaviors. There are more recent (2009, 2010) studies that show that
>> even small latency increases, such as 100ms, have measurable impacts
>> (obviously negative) on user experience and perception.
>> 
>> These studies describe experiments and go on to quantify the impact of
>> delays ranging from 50-2000ms on user behavior, number of clicks, and
>> such other metrics.
>> * http://velocityconf.com/velocity2009/public/schedule/detail/8523
>> * http://googleresearch.blogspot.com/2009/06/speed-matters.html
>> 
>> Other work along similar lines:
>> http://velocityconf.com/velocity2010/public/schedule/detail/13031
>> http://velocityconf.com/velocity2009/public/schedule/detail/7709
>> http://www.gomez.com/pdfs/wp_why_web_performance_matters.pdf
>
> If you care that much about latency, keep connections open and reuse them. 
> Reusing connections saves 1 RTT - the same amount you will save with IW=10. 
> Further, your IW won't matter, so you'll save that too.
>
> Second, you're saving 1 RTT. In most cases on reasonable nets, that's well 
> under 100ms. The cases where that's not true are where you probably don't 
> want to swamp the buffers (cell nets, bloated home DSL router buffers, 
> bloated OS buffers).
>
> Third, the reduction in latency is 1 RTT out of 3 *best case*. For very short 
> transfers. For anything longer, it's deep in the noise.
>
> Finally, I claim that this cannot possibly matter to the web. If it did,

Which scientific evidence backs up this claim ?

> people wouldn't design web pages using bloated images and flash; they'd use 
> simple HTML that would load and render faster.

By the same logic, smoking is not harmful for people - because if it were, noone 
would be smoking.

>
> If I have to wait 10-20 seconds after a page shows up just to see the first 
> content, can you really argue that 100ms is going to make or break anything?

This is not about the sites that take 20 seconds to load. This is about the 
sites that try to squeeze every millisecond for the better user experience.

We should not put everything into the same basket.

thanks,
andrew

>
> Joe
>
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