sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring DSL

I went to a guys house to installa phone line for DSL yesterday. Well, there were multiple lines coming into the house with none of them active. How do you tell which one is the DSL line?

By far, the easiest way is to purchase a butt set with the ability to detect the presence of DSL signal. Not cheap, but it sure does save a lot of time.

how do you do it w/o the buttset?

1. call the service provider
or
2. hook a modem up to each line until you get a sync lite

could you hook a voltage meter up to it?

you could but what would you expect to see ?

so then that means it wouldn't work?

Ditto what ^^^ Skip said.

Michael:

DSL is a signal that literally rides along the cable pair that provides dial tone. Even if this pair is half-open, the DSL signal gets through because it is only using the cable pair as the equivalent of an antenna.

Yes, it's true. The phone line carrying DSL may be out of order due to an open, yet the DSL still works. Pretty amazing if you ask me.

Your options as a technician are limited. Either invest in a butt set that can detect the presence of DSL signal on the line or do what the other posters have said.

You will spend much less time doing it this way than calling the service provider. Chances are, they don't even know where the signal is. A technician is only as good as the tools that he has at his disposal (assuming that he knows how to use them).

I do have to ask: Are you a technician or are you just learning? Your questions appear to be basic in nature. No offense intended, but it helps us to help others if we understand the extent of a posters' knowledge of the industry.

Not to well versed in DSL. I'm glad the client changed his mind about me doing the job. The unit had been remodeled and had no line running into it. One of the demarcs was active with DSL but not too sure which one. He changrd his mind about me doing the job because he didn't want me drilling into the wall.

I don't believe a buttset will detect the DSL signal until its synched with a modem

mine says "data detected " until the modem synchs there is no data present to detect

Skips correct, there is no DSL signal until the modem initiates a sync. By far the easiest way is to just hook the modem up the line to see if it syncs.

What about that annoying sound on a line with DSL?

I just use my butt set to listen for the DSL signal. It sounds like line noise with chirps and whistles. The dirtiest sounding line will have the DSL on it. Never fails.

so then, DSL does make noise on the line?

If you don't have the filters installed, or the interface in the NID doesn't have a "whole house filter", yes you'll hear static on the line when DSL modem has sync.

no modem.... this is at the demarc before it goes into the house

Then you'll need to hook up a modem at the demarc and wait for it to sync. Plug the modem into the test jack temporarily. If it doesn't sync within a couple of minutes, try another circuit in the NID (if there are additional circuits installed). Assuming the circuit has been installed correctly, then the modem should sync up. You could also bring along a laptop and verify you have the correct circuit by checking for internet access.

When I was doing contract DSL installations for a CLEC a couple yrs ago, I often times had the circuit ID on the workorder. If (and a very big IF) the LEC did their job, they tagged the circuit and tested the circuit. I also had a Colt-250+ test tool to test unlabeled circuits. Once I found sync, I called into the CLEC NOC and asked them to check the interface on the DSLAM to make sure I had the correct circuit and not some other CLEC's circuit.

Not *all* DSL circuits have "white noise" on them.

Some of them are not even visible with a Sidekick.

Some of them look like *very* long opens, while the other ones have battery and ground. I've seen ones that look like ground both sides as well.

Without knowing who the provider is, it's difficult to address the specifics. Colt 250 is a good tool, but won't detect every DSL. A provider-issued modem is likely the simplest way of testing.

My experiences only.

I hate to be so obvious, but couldn't you just call the carrier and ask which POTS has the DSL mashed down on it?

DSL is stupid simple. They bridge the DSL signal right on top of the POTS lines. End of story. Filters at the CPE prevent wild voice from contaminating the DSL frequencies that are introduced just outside of the hearing range (it's called a low-pass filter).

It's really a pipe within a pipe. There's the audible range--which is passed through, then there's the upper human/dog-hearing range; the latter being used to support data. Granted, this is a very over-simplified version of the story. But I assure you that my experience in the ATM/DSL realm holds ground here.

ajkula66 is right in that you can't hear the DSL hiss in some cases (it often depends on how young you are). I submit that most times you CAN by keeping your buttset in monitor mode and listening carefully. Old Rolling Stones fans are probably SOL.