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.com is 270-280...

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

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

-Aaron