[ale] [OT] DSL and latency

[Michael B. Trausch]

On Wed, 2009-09-30 at 22:07 +0000, Justin Caratzas wrote:
> On Wed, Sep 30, 2009 at 09:14:47PM -0400, PairOfTwins wrote:
> > However, when sites took 10 - 20 sec to bring up any content, I did a 
> > bunch of pings:
> > 
> > yahoo.com   ave 1313 ms, 12% loss
> > 2wire.com  ave 1661 ms, 4% loss
> > earthlink.net  ave 1466 ms, 0% loss
> > 
> > while my own Earthlink 3 mbit connection shows ave 85 - 140 ms, with 0% 
> > loss.
> > 
> > So, is Earthlink correct to blame the wiring in her home, or is it 
> > really their problem???  [note: all phones have filters]  My googling 
> > hasn't provided much to go on.
> > 
> 
> Have you tried different DNS servers? OpenDNS?

For the record, I missed the original post on this somehow.

To Tom:

1.3, 1.6, and 1.4 second return times for ICMP packets should be an
issue that the ISP should be concerned about.  Can you get statistics in
some form from the DSL modem?  I have the feeling that you'll find (if
it provides any) that it's probably whining about high levels of line
noise or some other issue.

To determine if it is the phone company's problem or the customer's
problem, take the DSL modem to the network interface box, and connect
the modem to a laptop (ideally) to connect through the modem, and see if
problems persist.  If so, the problem is on the phone company's side; if
not, the problem is in the wiring in the home somewhere.

If you can tell the tech, "Look, the problem still exists at the network
interface box", they should send send someone out to find and fix the
problem.

To Justin:

The problem isn't in DNS resolution, but in ping packet round trip
times.  The summarized output from ping there shows that there are
issues both with network latency and packet loss, which will affect the
usage of DNS but isn't caused by DNS itself; it's more likely that the
cause is the point-to-point link so common of DSL accounts, failing
equipment on the path between the phone company and the customer (could
be a failing CO or any router behind it or wiring in front of it, from
the POV of the DSL customer), or line noise either between the CO and
the customer or in the customer's home telephone wiring.  For a DSL
connection problem, I'd suspect the latter (the customer's in-home
telephone wiring) first.

	--- Mike

-- 
Blog:  http://mike.trausch.us/blog/
Misc. Software:  http://mike.trausch.us/software/

“The greater danger for most of us lies not in setting our aim too
high and falling short; but in setting our aim too low, and achieving
our mark.” —Michelangelo