Is DSL speed affected by phone line quality?

[purplehayes]

I think the title says it all, but I'll expand a little bit further:

I work with a guy that wants to get DSL for his new computer but is wondering if is current low connect speed will be a similar experience with DSL. He has a 56K modem but can only get online at speeds less than 30Kb/s due to poor phone line quality (I believe).

I'm a cable user so I'm unfamiliar with DSL service.

Thanks in advance.

PH

 

[reitz]

It may. If the problem is noise on his internal phone lines, then it will probably affect his speed somewhat.

It's still worth ordering, though. Most problems with low connection speeds have to do with the number of digital to analog conversions the modem signal undergoes on its way to the destination (the ISP's modems). With DSL, that is no longer an issue, since he would have a dedicated digital signal from his PC to the phone company's CO. I work for an ISP, and we offer DSL in an area with relatively poor line quality. Most users get very competetive speeds when switching to DSL.

Even if his line quality slows his connection down, it'll still be a heck of a lot faster than dialup, and so worth the money. If there are external line quality problems, he may benefit by going through a third-party provider such as Northpoint or Covad. In most cases, they run a new line, and so the quality of the phone lines in the area is not an issue.

Feel free to PM me if you have any more questions.

 

[sciencewhiz]

I have a computer with a modem and also another one with DSL. I have found that when my modem connects with a speed of about 25k or less, the DSL won't connect at all. In other words, you may get DSL, but your phone lines may be so bad that you won't be able to use it.

 

[reitz]

sciencewiz, if your phone lines are so bad that you can't use your DSL, then you might want to take a look at a few things.

Examine your internal phone lines, and make sure you have nice clean connections everywhere, and no unnecessary junctions that could degrade signal quality. Also make sure that there is nothing in your house that could be introducing extra noise on the line (halogen lamps, washining machine right next to phone wiring, refridgerator, etc). Also make sure that you have filters placed on all of your telephones, fax machines, satelite or digital cable receivers, etc., if the DSL signal is not split from the main line. You can have the phone company examine the lines, but if a problem is found on your end, they'll charge you an arm and a leg.

A fairly reliable way to test for noise inside your house is to try connecting with your modem several times (make sure it has a filter on it, if necessary). Keep track of the initial connection speeds, and try it again with the modem plugged into the interface box outside the house. Try to keep the variables the same (use the same phone cable, if possible, and keep the filter on there if you used it for the first test). If you notice a dramatic increase in connection speed and overall performance (a small amount is likely), then you may have some serious noise on your lines. If your connection speed is nearly unchanged, then the problem is likely on the phone company's end.

DSL should not be affected by day to day line noise and telephone traffic. With DSL, you have a dedicated connection from your house to the phone company's CO. The DSL signal is, for the most part, unaffected by the analog signal used for the rest of the phone traffic. Distance, for the most part, should be the only line quality variable that will affect your DSL speed, and that should be fairly constant. If there are no problems on your end, then it is possible that there might be something left on your line at some point that the phone company neglected to remove (quite common with Verizon).

I would suggest you call your ISP's tech support. I have a feeling that something inside your home is causing your problems, and they should be able to help you eliminate it. If they can't, switch to another ISP. If the problem in on your line, have the phone company re-examine it. If they won't fix it, switch to another provider, such as Northpoint or Covad.

 

[sciencewhiz]

Actually, we have had the phone company out to take a look at the lines because every once and a while there is a lot of static. They fixed one connection but it didn't help the static. The DSL has been better recently (last few days) and Pacific Bell refuses to come and look at it unless it isn't working when we call, and we can't guarantee that it won't be working when they come out since the problem is intermittant.

I will take a look at other things that might be causing interference, though. Thanks for the help!

 

[wyvrn]

Usually the phone company will have to clean up your line in order to run DSL, so this should improve your service. Distance from the Central Office also plays a part in download speed with DSL, with something like 17,000+ feet being out of range. When they install the DSL line, your actual phone connection should get better.

 

[R0b0tN1k]

If your DSL service requires the use of a splitter or filters, they could be your problem. A faulty splitter/filter won't separate the signals and might even be the source of the noise on the line.