[Cerowrt-devel] [aqm] the side effects of 330ms lag in the real world

Dave Taht dave.taht at gmail.com
Tue Apr 29 11:46:46 EDT 2014

On Tue, Apr 29, 2014 at 12:56 AM, Mikael Abrahamsson <swmike at swm.pp.se> wrote:
> On Tue, 29 Apr 2014, Fred Baker (fred) wrote:

A couple points here.

1) The video went viral, and garnered over 600,000 new hits in the 12
hours since I posted
 it here.

there is pent up demand for less latency. While the ad conflates
bandwidth with latency,
they could have published their RTTs on their local fiber network,
which is probably a
great deal less than dsl or cable. That counts for a lot when
accessing local services.

2) There is a lot of things an ISP can do to improve apparent latency
on the long haul

A)  co-locating with a major dns server like f-root to reduce dns latency
B)  co-locating with major services like google and netflix

publishing ping times to google for example might be a good tactic.

C) Better peering

>> Well, we could discuss international communications. I happen to be at
>> Infocom in Toronto, VPN’d into Cisco San Jose, and did a ping to you:
> 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.

Dave Täht

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