On Tue, Apr 29, 2014 at 5:46 PM, Dave Taht <dave.taht@gmail.com> wrote:


> > Yes, but as soon as you hit the long distance network the latency is the
> > same regardless of access method. So while I agree that understanding the
> > effect of latency is important, it's no longer a meaningful way of
> selling
> > fiber access. If your last-mile is fiber instead of ADSL2+ won't improve
> > your long distance latency.
>
> Well, it chops a great deal from the baseline physical latency, and most
> people tend to access resources closer to them than farther away. An
> american in paris might want to access the NYT, but Parisians La Monde.
>
> Similarly most major websites are replicated and use CDNs to distribute
> their data closer to the user. The physical RTT matters more and more
> in the last mile the more resources are co-located in the local data
> center.


With my DSL connection, 80% of the latency to "most" things (dns, cdns,
etc) is between the modem and dslam.  That's a place where fiber would fare
far better.  I get 20-25ms to the first router after the dsl modem, and
then akamai and google are within 3-5ms of that.

(and was that american-in-paris comment aimed at me?  ;)

La Monde is, amusingly, about 150ms from me here in Paris.  But
nytimes.comis 270-280...

And the CDN used by lamonde.fr is 60ms away.

And 20-25ms of all of that is DSL overhead.

-Aaron