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#160422 - 02/26/06 04:03 PM DSL went down
leespark Offline

Registered: 01/17/04
Posts: 54
Loc: Massachusetts
I'm finishing up a pretty large addition to a residence. The other day I connected the phone lines I had run to the existing phone service. We have abou 14 new cat 5 home runs for the phone. When I made the connections everything seemed fine, dial tone on the new and exisitng phone lines.

The next day the general contractor called me to tell me the DSL line was not working since I made the connections even though the phones were working fine. I had the general contractor disconnect the new cat 5 wires and the DSL came back to life.

What would cause this. Could there be too many linear feet of phone lines in the house causing the signal to drop? We added approx. 1500' of phone line.

Any help would be appreciated.

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#160423 - 02/26/06 08:39 PM Re: DSL went down
JoeTestingEngr Offline

Registered: 11/04/05
Posts: 786
Loc: Chicago, Il.
Was he able to disconnect the 1500' at one point? Is telephone all that has to be connected to the added cable? If so, try putting one of the DSL filters there, hooking the telephone split to the 1500'. That might buffer the DSL from all the capacitance that you're loading the lines with.

[This message has been edited by JoeTestingEngr (edited 02-26-2006).]

#160424 - 02/28/06 03:06 AM Re: DSL went down
pauluk Offline

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Is it likely that DSL was already borderline? How far is the place from the central office?

#160425 - 02/28/06 09:55 AM Re: DSL went down
hbiss Offline

Registered: 12/16/03
Posts: 893
Loc: Hawthorne, NY USA
Those would be called bridged taps and are the worst thing for DSL. Basically, they cause reflections that interfere with the transmission. The higher capacitance of CAT5 doesn't help either, should have used CAT3.

Yes, by all means put a single DSL filter at the entrance or demarc. The DSL moden should have a home run back to this location and should be connected directly, everything else gets connected after the filter.


#160426 - 03/01/06 03:42 AM Re: DSL went down
pauluk Offline

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Those would be called bridged taps and are the worst thing for DSL.

I gather that has been quite a problem in some of the larger cities as DSL has been added to lines.

In times past, it wasn't at all unusual for a phone line to be multipled to several places. Your line might come from the C.O. to a neighborhood distribution point, then it might be paralleled onto a cable which runs to the pole outside your house and also to other poles around the neighborhood.

There are stories in some of the telecom groups about people in apartment blocks in places like Chicago finding spare pairs (disocnnected from the C.O. but still multipled all around the neighborhood) and using them as private intercom circuits.

#160427 - 03/02/06 12:18 AM Re: DSL went down
e57 Offline

Registered: 05/27/03
Posts: 2837
Loc: S.F.,CA USA
"everything else gets connected after the filter."

Sounds like the problem right there... Filtered and un-filtered connected somewhere. Good sign of that would be the DSL working OK, then if someone picks up a phone it drops out. They may even have called tech support on that same line....

Anyway, Hal is right, a single DSL filter and to the modem, network from there if need be. And the filtered voice also distributed from there.

And some may disagree about the need of additional cabling. But my prefered method (except for people who can handle having a remote modem) is 2-cat5 and 4-pair phone (One of which would be unfiltered DSL) to most locations. This way you can still have the modem next to a computer anywhere, and LAN back to a hub in a remote location, then back to the computer it may be next to.
Mark Heller
"Well - I oughta....." -Jackie Gleason


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