Access to DSL
janowskij
Newbie

Just a simple question: If a house has an established landline with Verizon, is that a guarantee, or if not is it at least likely, that the same location can also recieve internet service? The home is in a slightly more remote location near two smaller cities that both utilize verizon services. Just gauging how possible this is more or less.

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Re: Access to DSL
Capricorn1
Community Leader
Community Leader

I haven't had Verizon DSL for a while as we were fortunate enough to get FIOS, but when I did have it, whether or not you could get DSL was not cut and dried. I don't know if that has changed. I doubt it.

DSL has very real, fairly short distance requirements. Essentially any long copper wire starts looking like a resistor rather than a conductor. The longer the distance, the more the resistance. Therefore, the distance from where you are to where the phone company's central office (CO) is matters. DSL uses a very wide spectrum of frequencies compared to voice, which uses a very narrow, low frequency range. More and more of upper frequencies become usable as the distance increases. The maximum for DSL of any kind is about 18,000 ft from the CO. The maximum speed of DSL at that distance is much less (about 300Kbps) because the usable frequency range has been diminished greatly.  It also matters how the wire is run. Even though you may be able to throw a rock to the parking lot of the CO from where you are (not endorsing that action), if they run the wires several thousand feet in another direction before it gets to you, it's several thousand feet away. There is a chart of distance vs expected speeds, here. (Fiber also has an anologous issue, but at much greater distances.) And here is another article explaining DSL limitations.

I was lucky enough to be only 4,000 ft (wire-run-length-wise) from the CO. Verizon was constantly trying to upsell me faster DSL (technically ADSL). The prices were way too high for me to do it though. Distance is not the only factor. I had a friend who lives about 10 miles away from me, but in a much newer sub-development. To save money, the phone company ran fiber from the CO to a remote office in his neighborhood and then copper from there (typically called the "last mile") to his house. Unfortunately, they provisioned just enough fiber to handle time multiplexing the voice traffic and left nothing for data. He was technically close enough to the CO (not just the remote office), but because he didn't have copper the whole way from the CO to his house (and the remote office didn't have DSL equipment in it), he couldn't get DSL. (He now has FIOS, but they had to run new fiber to each house in his neighborhood as they did in mine.)

Another person I worked with was about 7,000 feet from the CO, but had real trouble getting DSL as his house because of bridge taps. Bridge taps are how new service is connected to the existing phone lines. He lives in a very urban area where phone service has be connected, disconnected and moved many times over the years. There were a lot of unterminated bridge taps from that. Every one of those degraded the signal a little bit. They effectively ended up running a new line from the CO to his house. (At that time, it was worth it to Verizon as he was getting the very high cost, high speed ADSL to run a business from his house.)

In addition to bridge taps, there are also load coils. These are specifically used to squelch all of the frequencies on the copper wire other than the range used for voice. Those kill DSL signals outright. They were used where the higher frequency noise on the phone wire was interfering with other phone wires. I don't know anyone who ran into this problem getting DSL, but I just know they were a potential problem. I found a bit more about bridge taps and load coils here.