Connect with us

pabx caller id bypass

Discussion in 'Electronic Basics' started by peterken, Dec 4, 2004.

Scroll to continue with content
  1. peterken

    peterken Guest


    I was wondering if anybody knows how to bypass a PABX for caller-ID
    information, so the internally connected handsets having the feature of
    showing caller-ID actually show it...
    Most PABX do not transfer this caller-ID information to the internal lines
    Could it be done using some passive filter system ?
    Or does it need optical insulation and active parts ?
    Did anybody here already try to bypass it ?
    Has anybody have any information on the signal level and "frequency" of
    caller -ID ?
    (I do know it's sent *before* the actual ringing signal, but that's about

  2. Mike

    Mike Guest

  3. Dmitri

    Dmitri Guest

    peterken wrote:

    Most current PBX do transfer caller ID to their extensions, as long as the
    analog trunk interface cards are of Caller ID supporting type. Some older
    (Key systems) can also be upgraded to support caller ID by updating their
    processor card (and trunk card(s) where needed). You cannot actually
    bypass the processor board of the PBX to make the Caller ID ride to the
    extension for several reasons:
    #1 the phone sets should have internal feature to show Caller ID, and not
    just the display. Only analog phones would qualify, not the PBX feature
    #2 the processor actually stores the Caller ID info, and then transfers it
    to the feature phones using its own, proprietary protocol. This protocol
    is pretty heavily guarded by the manufacturers (because it lets them sell
    more feature phones), and it is not the same as the Caller ID you'd get
    from the PSTN to your regular house phone.
    #3 it is the processor that decides which extension the call will go to,
    so how do you know beforehand which extension is going to receive the
    CallerID sequence?

    If you get lucky, and you have a key system (not a PBX), and your trunk
    cards are supporting Caller ID, you may try to use a separate caller ID
    device to see if it actually gets through or, alternatively, hook the
    caller ID device directly to the incoming lines, especially if your
    extension is only picking up one line.

    Good luck!

    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 Archiv
    no-spam read and post WWW interface to your favorite newsgroup -
    sci.electronics.basics - 7185 messages and counting
  4. peterken

    peterken Guest

    - well, it's an analog pabx, call it an internal central passing calls from
    outside line to multiple internal phones
    - depending on who picks up first gets the call
    - more as one internal phone supports caller-ID
    - the actual switching in the pabx is done using ordinary relays
    (might be interesting : type pabx is Profoon CX28 see under )
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day