Phone line out, DSL line in.

They hook your phone wires through a dsl unit in the switch room. That means, that even with the input wires broken or disconnected, the outgoing wires from the dsl unit still carry the dsl signal. So, yes ,your scenario is quite possible.

I just went thru this. No dial tone, but DSL worked. I disconnected the line. Had -50V on one wire and zero on the other. Looks good to me... but it wasn't zero because it was the ground return. It was zero because squirrels had chewed thru it half a mile away and that line was open. The DSL managed to get thru the hot wire and the earth ground at the junction box. The phone needed a good return line. Sounds like yours might be shorted somewhere keeping the line off-hook.

In article , micky writes

One of the 2 wires is broken somewhere. That would kill phone service but DSL still works because it's near radio frequencies and the single wire still connected acts as an antenna.

Yes

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Here the DSL is sent over the POTS twisted pair from a box on the next block, thus negating the "maximum" distance problem with using a 3KHz distribution system for 10Mhz or more signals.

If you don't have one, get a DSL splitter (outside)and use new wiring to your DSL Modem. Even if it's a modular cable from Rat Shack or Beast Buy, it's probably better than whatever's in your walls. Here we can't get DSL without voice.

Yours was open fialed the low frequency stuff, of course, but the high frequency could still get through.

OP might have a 'short'which caused the switch house to 'think' he's always OFF HOOK, probably went through that sequence of loud recording followed by no more POT line power, thus he hears dead silence, no calls come through and callers get BUSY tones.

So, disconnect your line from the houw wiring, measure the impedance between lines at your box, if it's not you call the phone company. If it's you, start tracing down the problem.

When this happened to me, it was traced to a short-circuit between my house and the SLC terminal. One symptom was that the on-hook voltage was about

3V, which was attributed to corrosion between the splices of the wire pair (underground, about 10m from my house). There was enough signal getting th rough for my DSL to work, but the system thought my telephone was off-hook.

As to the question, everyone who attributed the DSL working to high frequencies was probably right. The Verizon woman on the phone also said the phone and dsl used different frequencies. Thanks everyone.

As to the problem, I was going to measure voltages, but first I went outside to check things. Verizon will now check one's line and she said they could tell if the problem was at their end or mine. She said she got a green meaning the phone company's situation was good. One can also do the same test online, and then it follows with more instructions on testing (which I assumed would be helpful but later realized it was no more than what I already knew (disconnect each wired to see if the dial tone comes back) , and arranged in an order that wasn't best for me.)

So I did get a dialtone outside the house, and then I tugged on the ends and pushed in on the ends of the 12 inch modular wire I was using to connect to the round wire. Then I went in and for a few reasons forgot to test for 5 more hours, at which time everything worked.

So it either fixed itself after 32 hours or more, or my fiddling with the wire restored a connection. Thanks everyone for the help.

I'm going to replace the chain of modular wire - round wire - modular wire with

The real reason for those RTs (Remote Terminals, a Central Office in a box) is the lack of useable copper pair capacity from the old big building COs. Not only has there been a lot of growth in population density, but much of that old copper infrastructure is in bad shape and many pairs in it are unusable.

One big problem with those RTs is the lack of backup power. They have batteries which will hold them for eight hours or so when new, and a lot less in a few years of baking in the sun and freezing in the winter. Unlike big building COs they do not have permanently installed backup generators.

The Telco has towable generators to theoretically back up the RTs, however the ration of RTs to generators is large and a big storm can both exhaust the generator supply and also make towing them to some RT locations difficult with flooding, downed trees, etc. Cell service is now more reliable than land lines, since the cell sites do have generators and fuel supplies to last at least a few days.

As for DSL working and voice getting a busy signal, remember that it does not take a short to take a line "off hook", rather it takes a certain amount of current flow which means that a corroded damaged cable could provide a partial short enough to take the line "off hook", but not prevent the DSL from working to at least some extent.

DSL uses the same two lines as the phone. No one mentioned a splitter or f ilters.

Have Verizon install one for you OUTSIDE in the NID. There new ones are re ally cool in terms of what you can do testing wise.

The NID typically presents a 1/2 ringer load.

The splitter basically brakes up the DC and ring signals and passes the voi ce band which includes about 3 Khz. Frequencies up to about 5 MHz are used by the DSL modem in bands.

I have the worst interior lines in terms of number of phones, locations, be lls and non-home run, Mostly quad wire. The Telco guy says the DSL is pri stine though. The original splitter I installed in the NID. When the NID was installed a length of 4-pair was run inside the house.

The highest pair, I reserved for DSL. The DSL section is about 3" to a punc h down block and then to a CAT3 RJ11. I run CAT4 RJ11 direct to the modem about 5 feet away. The DSL line can be polarity reversed, so I use a strai ght thru Cat4 RJ11 cable.

Telco is a hodge-podge mess mostly installed by the phone company in the 60 's. There are basically two origin points and some piggy backing off of ex isting jacks.

I'm planning a switch at the DSL modem that will do modem #1, modem #2, Rev erse, normal. but I haven't rewired the switch to CAT5.

So, telco goes to a carbon surge protector/studs on the inside, which I cou ld pull the carbon out because surge suppression is also done in the NID.

For now, it works, but a few internal lines have been disconnected. Spider s and water. I did make a few quad wire to CAT4 spice boxes. The first on e is not quite in service yet, A non-removable terminal strip for the quad wire and a removable strip for the CAT4 so I can easily disconnect the one that likes to get water in it. I'm in the process of installing a CAT6 pa tch panel for network and phone. It's currently vacant right now,

Anyway back to DSL. If the Modem is connected and powered on to the DSL li ne without a filter or splitter you will hear a high frequency hiss in any phone without a filter, Turn off the modem and the hiss goes away. Picki ng up a phone could cause modem issues if turned on.

The phone will work if the DSL modem is off and the modem will work as long as no phone is picked up if there is no splitter or filter.

Filters are limited to 4 or 5, I think 4. You only need a single splitter and the DSL quality goes up.

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