Phone adapter for existing home wiring

Discussion in 'VOIP' started by Jim Gross, Dec 18, 2004.

  1. Jim Gross

    Jim Gross Guest

    Does anyone know of an ATA that explicitly supports multiple devices
    on existing home wiring?

    I have 5 phones, 1 answering machine, 1 computer modem and one caller
    ID box on my telco quad "backbone." I'm looking for an ATA that I can
    just connect to a jack on the backbone after disconnecting from the

    None of the vendor lit I've seen supports this. They all want you to
    connect your phone(s) directly to the adapter with RJ-11 patch cables!
    Some of the VoIP carriers seem to wink at existing wiring setups as
    long as you don't have more than 3 - 5 phones connected. But they
    make it clear there are no guarantees, so I guess the risk is on the

    Jim Gross, Dec 18, 2004
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  2. Jim Gross

    Mitel Lurker Guest

    Start by finding out what the Ringer Equivalency Number (REN) is of all
    the devices you're wanting to connect and add 'em up. Each phone + modem +
    answering machine. Once you have that total then look for an ATA that
    supports that high of a REN. Good luck in finding such a device.

    As for "guarantees" I found there are really only two you can count on;
    Death and Taxes.

    Mitel Lurker, Dec 18, 2004
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  3. No vendors explicitly support this for liability reasons. If you don't
    know what you're doing and you connect the ATA to a live phone line
    you'll probably fry it. That said though, you can do what you want with
    just about any ATA. Most have a REN of 5 (same as POTS) but some are
    only 3, so you may have issues with ringing if you connect too many
    phones to them. I have a Vonage Motorola VT1005 feeding 8 phones in my
    house and everything works just fine.

    Nick Zivanovic, Dec 18, 2004
  4. Jim Gross

    Ivor Jones Guest

    You can get REN extenders that allow more phones, up to 8 or so I think.
    Maplins sell them but they require mains power and aren't cheap from
    memory. Might do what you need though.

    Ivor Jones, Dec 18, 2004
  5. Jim Gross

    Jim Gross Guest

    Thanks Nick, and also Ivor and wdg, especially for reminding me about

    The sum of the RENs of my current devices is 3.7 so I expect a REN 5
    phone adapter will meet my existing needs. I'm leaning toward Vonage
    and a Linksys PAP2 ATA right now rather than a router/ATA combination
    device since I already have a wired and wireless home network
    installed with an SMC Barricade router and a Linksys WAP.

    Otherwise, I have done my own phone wiring for years, I know where my
    demarc is and have phone line test equipment and know how to use it,
    so I feel comfortable about effectively disconnecting the POTS line.

    Given the above and your experience with VoIP, are there any other
    installation issues I need to consider, besides selecting a VoIP
    carrier and plan?

    Thanks again.
    Jim Gross, Dec 19, 2004
  6. Otherwise, I have done my own phone wiring for years, I know where my
    That should work. When you unhook the line at the demarc, be sure to
    do something to give passing phone guys a hint that it would not be
    helpful to plug the line back in. I put black tape over the jack.
    John R. Levine, Dec 20, 2004
  7. Jim Gross

    Dmitri Guest

    Jim Gross wrote:

    REN number (number of phones connected in parallel) cannot be guaranteed
    simply because there is no reasonable way to calculate it! One unit was an
    equivalent of one electro mechanical ringer. Nowadays the phones became
    electronic, and their impedances are hundreds (thousands?) times higher
    than that of the old-time ringer's coil, so the REN number makes almost no
    sense anymore. It does not mean that you can connect thousand of the
    phones in parallel because they'll draw power during ring and the call, so
    the reasonable number is still within 10.

    By saying "multiple devices" you don't mean multiple separate extensions,
    do you? I have heard of a system that supports multiple extensions over
    the same pair of wires, but this is a rather esoteric setup. Will be
    really hard to find and very non-standard.

    Dmitri Abaimov, RCDD
    Cabling Forum, color codes, pinouts and other useful resources for
    premises cabling users and pros
    Residential Cabling Guide

    Article posted with Newsgroup Archive
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    comp.dcom.voice-over-ip - 1482 messages and counting!
    Dmitri, Dec 23, 2004
  8. Jim Gross

    Marc H.Popek Guest

    Marc H.Popek, Dec 25, 2004
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