DSL lag when switching sites

I hope I'm not asking a tiresomely common question here-- my search through this group so far has not turned up any information that directly addresses my problem.

I have a DSL connection with AT&T and an Actiontec DSL modem/wireless hub. All the computers on my network are Macintoshes running OS X.

My problem, which I have not observed before with other DSL providers and different networking equipment, is an approximately ten-second lag before connecting with a website, if the last communication on the network was with a different site. If the last exchange was with the same site, there is no such lag.

So for instance if I search something using Google, I can expect a >10 second delay before the Google search window pops up. When I enter a search term, the results appear almost instantly. If I keep paging through the results, it's all very fast. But when I click through to another site, that >10 second delay reoccurs. And then when I go back to Google, I get another delay.

I'm beginning to get a sense of the hours and hours of wasted time this all adds up to, and I wish I could figure out how to avoid the lag every time I connect with a different site than the one I last hit. As I said, I never noticed any such lag on my earlier household networks, and when I use my laptop on other wireless networks, it does not occur.

Is this likely to be something my DSL modem is doing, or is it my internet connection itself? If it's the modem, is there anything I can do to fix it other than get a new modem?

If I do need a different DSL modem, can anybody recommend a good fast one that will play nice with my Macs?

Please accept my thanks for any advice you can provide.

Chalo

Reply to
Chalo
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"Chalo" wrote

Sounds to me like your DSL line is SLOW. Try this to see:

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Reply to
Ken Abrams

It's possible it's a DNS problem. AT&T's DNS servers may be badly overloaded.

Here is a simple test: Enter these in your browser address bar:

http://64.233.167.104/(that's Google).

http://207.46.19.190/(Microsoft)

http://17.112.152.32/(Apple)

If the delay is gone, it IS a DNS problem. If the delay is still there, something else is wrong:

  1. Is your wireless running wide open (no encryption)? Maybe your next-door neighbor's kid is using all your bandwidth.

  1. How MANY computers do you have on your LAN? Are they all using the connection to download music? Is your wireless LAN saturated (running an iTunes server on one machine, streaming to all the others)?

--Gene

Reply to
Gene S. Berkowitz

Gene S. Berkowitz wrote in part:

An excellent response. I would add that music "sharing" _UPLOADING_ is actually much worse for DSL and other asymmetric links. Due to the TCP capture effect, once the uplink is saturated, the downlink slows drastically as TCP ACK packets are delayed.

Many music "sharing" programs enable upload by default, and this is both a legal and technical problem.

-- Robert

Reply to
Robert Redelmeier

That appears to be the problem. Drat. I'll contact AT&T and see if I can get alternate DNS addresses.

I had thought of that, but most of my neighbors are doing well just to have electric lights-- they are almost all first and second generation Mexican immigrants with far more pressing uses for their time than to surf the web. The one person within range whom I would assume to be an internet user appears to have her own (password protected) connection. So I leave mine open on the off chance that one of the neighbor kids has a school-related laptop or something. So far I've seen no clues to that effect.

Nope, nothing like that. I have two G4 Powerbooks and one old G4 box in my house. The heaviest volume they ever see is occasionally loading one YouTube video after another, and they are pretty fast at that. The speed seems fine-- it tests out at 1.25Mbps or so (I have been promised at least 768kbps and no more than 3.0Mbps by AT&T).

It was the odd combination of good and consistent download speed with laggy and slow initial connection that had me frustrated. Your guess at a DNS problem seems to be right on the mark.

So here's a follow-up question: Since there is minimal to no lag in connecting by way of IP addresses, how do you determine what the numerical IP address for a given domain name is? I'd like to change my bookmarks over to just the IP address numbers. If I could eliminate the lag just on my routinely accessed sites, that would make a world of difference.

Thanks for your help.

Chalo

Reply to
Chalo

Chalo:

Such a look up utility is known as "Dig". There are web based versions you can use for free:

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You might also try Googleing for "free DNS servers" as an alternative to AT&T's.

HTH & GL

John

Reply to
John Dulak

I have used Dig and WHOIS to find IP numbers, but that doesn't seem to help in accessing things like news.google.com or groups.yahoo.com. And when jumping from the main site to a subdomain like one of those, I get the dreaded lag. I guess I'll have to resolve the DNS problem instead of working around it.

Thanks for the tip.

Thanks to all for such helpful and prompt advice. I believe I have learned enough to pursue the matter further on my own.

Chalo

Reply to
Chalo

You can dig for IP addresses to use, but there is NO guarantee that a particular IP address will still work in the future. That's the beauty of DNS; the IP can change, the change propagates automatically to all other DNS servers, and no one has to do anything except remember the name...

By netiquette, you're not encouraged to use DNS servers other than those offered by your ISP, or those that declare themselves free to use. You might find, however, that the DNS servers of a nearby college or university offer better response.

AT&T does have MANY DNS servers, so you might start googling to find their IP addresses and try those.

Good luck,

--Gene

Reply to
Gene S. Berkowitz

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