Telephone - DSL question

I’ve had ADSL for the past couple years at our house. We just moved and it is not available at the new one.

When I asked the installer why I couldn’t get it (he had to hook up the phone service, as the house was brand new) he said it was not the distance, but the type of line. Our old house is two blocks away from the new one but it is a 10 year old neighborhood. The new house is in a “new” neighborhood. The old house has “copper” lines and the new areas have “fiber” lines. He said DSL does not work on Fiber lines.

Now, I am not a phone expert by any means, but that just doesn’t make much sense to me. From my limited knowledge, I was under the impression that Fiber Optic lines are superior to copper based ones. He did mention that it is a “problem that is getting worked on” but didn’t elaborate.

Can anyone fill me in as to why it won’t/can’t work? Does it have something to do with the two signals (I think) that has to be run on a DSL line? (regular phone and DSL) that can’t be run on Fiber?

I’m confident that someone who knows this topic a lot better than I do will jump in shortly, but until that happens…

Yes, I’ve heard that many “new” neighborhoods can’t get DSL (as well as a lot of older ones) even though they’re close enough to the local CO. I haven’t heard this as being a case of fiber vs copper, but as being a case of multiplexed vs non-multiplexed lines.

Older neighborhoods were wired through to the local CO on a one-to-one basis. IE, a copper wire from your house to the CO would be just that - a single strand of copper carrying only your phone signal. That strand of copper is just fine for both voice line and DSL purposes.

Newer neighborhoods, though (and older neighborhoods that got built up to the point that the number of voice line needs exceeded the original copper) often have multiplexed lines. There, several distinct copper lines that go into individual houses are merged onto a single strand of copper with a device (whose thre-initial name I forget) that multiplexes the different voice signals over that one wire. At the CO they’re de-multiplexed back onto single wires.

That trick works great for voice lines - but it’s death for DSL. The multiplexing device uses only voice-grade frequencies, deliberately filtering out other frequencies (including DSL) as noise.

The device is a “SLC” (pronounced slick), short for “Subscriber Loop Carrier”. They’re neato-cool devices that (usually) jam 96 homes over one T1-rate line (1.544Mb/sec).

Do the math and you find each home gets about a 4KHz bandwidth which is just fine for voice but, as you said, death for DSL.

AHA! It’s called a DLC (Digital Loop Carrier) or SLC, and there’s an excellent explanation of what they are (along with lots of other reasons why some golks can’t get DSL) at the link below:

(Sorry for not knowing how to make this fancy)

The good news is that these folks claim that newer DLCs can support DSL, and older DLCs can be replaced with newer ones. Also, fibre isn’t mentioned as being an issue (and it’s been my experience that these folks typically know what they’re talking about - they posted a fix or the Cisco Router / Code Red virus problem that saved my butt long before either the folks at Cisco or Quest posted one).

Also, I referred to these devices as “multiplexors”, but these folks refer to them as “concentrators”. My bad.

And he’s correct that current DSL services are designed to use copper wire between your house and the DSLAM in the CO.

Fiber optic is multiplexed at a neighborhood concentrator before it gets to the CO, for one thing.

They apparently have to install mini-DSLAM hardware at the neighborhood concentrator.

Fiber optic IS superior - but you are paying a penalty for being a bit ahead of the curve here. At least, when the broadband service is made available, you should be able to get higher speeds than either DSL or cable modem service. - say 10 mbit. A lot more is theoretically possible, but affordable residential services using fiber will probably be in that ballpark.

Here’s an article on fiber to the home:

If you look around on, you can find some more background. You aren’t the only one in this boat. There are a few “broadband dead zones” in the country in areas that aren’t out in the sticks, but are SOL because they have nice new fiber-to-the-curb, but no broadband providers selling internet services over the fiber yet.

In the meantime, maybe you can get cable modem service.

Great info! Thanks!
So hopefully, I am just a “wee-bit” ahead of the tech curve…

As for cable, yes I can get it, but I refuse too. The cable co in this city is a monopoly and they have really shitty service (as in the actual cable service) and their cust service is bad too. They have a hard enough time keeping the cable TV signal clean, let alone run a network.

They want $400 for some pimple faced kid to “install” the service onto your PC (and no, they won’t let you do it yourself) PLUS!!! You must buy THEIR modem and pay twice the monthly rate for 1.5MB DSL.

No thanks, I’ll stick with my 56K dialup before I consider cable with those asses.