Zap channel for outbound only/ No inbound pickup

Discussion in 'General' started by Patrick_elx, Jan 28, 2009.

  1. Patrick_elx

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    Hi,

    I have a POTS line I'm using for an analog fax and DSL for my pbx.
    I would like to use this line with the pbx only for outbound 911 calls to have a proper E911 info.

    I've setup an infamous X100P card that is fortunately detected properly on this computer.

    My problem is when I connect the line to the pbx, my analog fax does not pickup anymore, however asterisk shows a 'starting simple switch on Zap' and start the from-zaptel context.

    As seen in different forums I've tried the following without success:
    - route the DID associated to the ZAP to a 'hangup'. I see the hangup in the trace, then another hangup, then another hangup and so forth as long as the line is ringing.
    - in the zapata-chan.conf I've played with the immediate=yes or immediate=no without any changes
    - I've commented out the faxdetect
    - I've changed the fax setting to pickup immediately, after 1 or after 2 rings.

    Anything I'm missing here?

    Patrick
     
  2. dicko

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    Try connecting the pbx to the "phone" jack ( not the "line" jack) on the fax machine and not to the wall/dsl filter directly.
     
  3. Patrick_elx

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    That's probably a solution that will work, however that's what I was trying to avoid as I do not have a spare wire left in the room that has the fax.
     
  4. dicko

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    Two possible solutions here,

    1, You might be lucky and your building might be wired "two-pair", pop off the wall plate and see if there are four wires connected to the jack, if so you might be able to return the phone jack on the 2nd/orange/yellow-black pair if it is otherwise unused with the judicious use of some "line splitters" at either end.

    2


    Kludge extensions_additional.conf by adding

    exten => s,n,wait(6) after the s,1 extension.
    (this might break freepbx/Elastix upgrades so a better solution would be to make a custom context that does the same thing but survives upgrades.

    for example

    [from-zaptel-kludged]
    include => from-zaptel
    exten => _X.,1,wait(6) ; 6 second delay till answer
    exten => _X.,n,Set(DID=${EXTEN})
    exten => _X.,n,Goto(from-zaptel,${DID},1)

    and change the context for the zap trunk to from-zaptel-kludged

    restart asterisk and that should work
     
  5. jandir

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    I had the same problem and had asked about it in the forum long ago but never got a satisfactory answer.

    so I setup a virtual fax in Elastix and receive faxes directly to elastix (which emails them to me) and have also setup fax autodetect (nvfax) so people can also leave a voice mail at the number.

    Now I use my analog fax machine to only send faxes (No auto answer). I would recommend that you do the same. It is definitely better that receiving faxes on paper and very easy to setup (Elastix without Tears + Search for NVfax on the forums if you want fax autodetect).
     
  6. Patrick_elx

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    I've tried with the modified context.

    I still have the first line in the log as
    Starting simple switch on 'Zap/1-1'
    and then it goes directly to the context and execute the wait statement.

    And the fax is ringing, ringing and ringing but not answering.

    This damned fax detects somehow that the card has taken over and refuses to answer...

    Patrick
     
  7. dicko

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    I don't think it's the damned fax but just damned physics (and the damned X100P)

    The fact that the fax is ringing (but not answering) suggests that the X100P's parallel presence (and state) on the line is too low an impedance, thus reducing the line voltage (nominal 48v) and ringing voltage (nominally 90volts) to a level below which the fax's modem will recognize the ringing. (apparently not so for the "bell" circuit).

    Given your understandable reluctance to put these devices in series then:


    Steps I might take here:-

    Many faxes have deep within the menu structure an entry which is designed to let them work behind traditional PBX's where often the battery is 24volts and ringing is only 48volts, it is sometimes called line type or such. If you can find, it change it.

    Try and plug the fax into the "phone" jack on the X100P (a long shot but maybe the hardware has some ring regeneration on it, I doubt it but . . . )

    Add some resistance in series with the X100P input. (maybe somewhere between 200 and 2000 ohms?).

    My favorite would be to carefully remove the X100P from the box, put it in the microwave for about 45 seconds, wrap in a clean paper towel and then put it where it belongs (in the trash can.) and replace it with a linksys 3102.
    After all we all know we get what we pay for and you are going to rely on this device for 911 service.



    p.s. I forgot to "include" the needed context in my snippet, I hope I've fixed that
     
  8. Patrick_elx

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    What setting on the microwave ? ;)


    I'll try the other solutions and I will also start playing with my oscilloscope to check what's happening on the line with and without the card.

    I'm not too worried about this issue as it's my test box I'm playing with. But fixing these kind of problems are a great way to improve my understanding of the whole system. And not finding the reason is driving me crazy.

    I've played with a gxw4104 and it worked in the same setup (I know, they are not as good as the linksys, but better than the X100P anyway). I'm just worried that I can have the same problem with a Digium card I'm planning for the final setup.
     

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