[ale] [OT] DSL and latency

PairOfTwins PairOfTwins at mindspring.com
Wed Sep 30 22:47:30 EDT 2009


Michael:

Good suggestions!  I'd like to take a laptop over and locate the phone 
line entrance.  This is a really old house.

When name lookup was slow, I used a server suggested by 
dnsserverlist.org, with no improvement.

Drilling down in the modem I found:

noise margin upstream 12 db, downstream 9 db
output power upstream 8 db, downstream 1 db
attenuation upstream 4 db, downstream 7 db

and when I read these to the Indian script-based tech support, she 
thought is was normal.  What do you think?

Tom
====================================================
Michael B. Trausch wrote:
> 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
>
>   


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