Desktop

Ask something
Discussion Locked

What is DSL?

0 helpful
13 replies

by northwood

Closed to new repliesThis discussion is closed. It stays readable, but it takes no new replies.

I am researching DSL and so am a bit confused on how it works.

Is it true that DSL uses the same telephone wire line as your telephone?

Is it then true that DSL emits a digital signal on to the telephone wire while the telephone emits an analog signal on that same wire?

13 replies

by opatzg9

I'd have to say no no no, or the type of wire running through your neighbohood may matter as well. I am not able to get DSL where I live. It may just be that the basic support systems in place for telephone here are not DSL compatible and newer wire and switches can handle both. ut the phone company has told me it willl be at least 4 years before we have that support.

by paulp

Check out this site for all sorts of info on DSL.

www.dslreports.com

Yes, DSL is delivered to your home via the same phone line you use for voice. You put special filters on every voice telephone you use to filter out the DSL signal.

by timwalsh

Yes, DSL does use the same cabling as your phone.

The DSL digital signal is regenerated (or amplified) by the telephone company central office (CO) closest to your home. The farther the signal travels, the more the signal strength is degraded until data cannot be reliably passed. The commonly touted maximum distance from a CO for RELIABLE DSL data is 18,000 ft. (or roughly 3.5 miles).

The age of the telephone wire infrastructure in a given area can also prevent DSL from working (or being available). Generally, if you are having problems with line quality for your telephone, DSL will not work.

by thechas

DSL:
Digital Subscriber Line

Assuming your phone line is up to specification, yes it does use the same wire for both voice and data.

DSL does have distance limits from the central switch that services your phone line.
The farther you are from the switch, the slower the DSL connection speed.

In some instances, the service provider may need to run a separate line to provide DSL service.
This can be done to shorten the distance between the installation and the switch, or to bypass a fiber-optic link. (DSL only works on copper wire)

Whether it be Dial-Up, DSL, or Cable, the "DATA" signal is an analog signal modulated to transmit digital data.

DSL can add a high frequency noise, sort of like holding a sea shell to your ear, tothe analog line.
That is why you need to install DSL filters on your phone lines.

I installed a POTS / DSL splitter which does an even better job.
(POTS Plain Old Telephone System)

Chas

by gseery

DSL uses the same physical lines as your old phone system. The signal is a digital signal, transmitted at a frequency above the normal frequencies used for analog voice. Voice signals are transmitted from about 100 hz through about 20,000 hz, the DSL signal will start at 35,000 hz and go on up.

The splitter/filter should be supplied by the provider, it prevents interference from the very high pitched DSL signal from possibly interferring with your normal conversations. If they don't give youenough, you can either go back to them and ask for more, or get them from something like your local RadioShack.

DSL service and speed is heavily dependent on the distance from your Carrier Office (CO) to your site. If the primary reason you want DSL is for speed, and you are further than about 2.5 or 3 miles from the CO, you won't get that much of an increase. You will be paying around $50/month for what is effectively just a second phone-line.

To get an estimate on the distance from your CO, go to this CNET Prequalification site, it will estimate the distance from your CO, along with giving some (not all) of the providers you have available. http://webservices.cnet.com/prequal/

This discussion is closed to new replies.