Will a fax machine work on voip?

Discussion in 'UK VOIP' started by John, Apr 2, 2012.

  1. John

    John Guest

    All in one phone/fax machine. If you switch to voip and use it
    through an ATA, will the fax machine still work?

    --
    John
    John, Apr 2, 2012
    #1
    1. Advertising

  2. John wrote:
    > All in one phone/fax machine. If you switch to voip and use it
    > through an ATA, will the fax machine still work?


    If the ATA uses the same codec as the PSTN (G.711 A-Law in the UK) and
    the propagation delay is low enough, it should work. (G.711 mu-law
    should also work, at least as well as faxing to the US).

    If it uses T.38 encoding of fax and regenerates the fax signal, it
    should also work.

    If it uses GSM or G.729 without T.38, there is no hope.
    >
    David Woolley, Apr 2, 2012
    #2
    1. Advertising

  3. In article <jlbcd4$4ie$>,
    David Woolley <> wrote:
    >John wrote:
    >> All in one phone/fax machine. If you switch to voip and use it
    >> through an ATA, will the fax machine still work?

    >
    >If the ATA uses the same codec as the PSTN (G.711 A-Law in the UK) and
    >the propagation delay is low enough, it should work. (G.711 mu-law
    >should also work, at least as well as faxing to the US).


    It's not so much propogation (latency) as jitter and packet loss.

    Although I've demonstrated it working, I'd never give anyone any
    sort of guarantees whatsoever of it working for real.

    >If it uses T.38 encoding of fax and regenerates the fax signal, it
    >should also work.


    If you can find a provider that'll terminate the T.38...

    >If it uses GSM or G.729 without T.38, there is no hope.


    Indeed.

    Basically, it might work and if it does, then great, but doesn't
    expect it to and use something else - e.g. email. What I have done
    for clients in the past is ported their FAX number to a FAX to Email
    service, then connected their legacy FAX maching to their standard
    BT line for outgoung faxes (and make sure they withold the number
    so people don't try to fax back on it) That seems to work fine when
    people have a small number of FAXes to send, but still need to recieve
    them.

    Gordon
    Gordon Henderson, Apr 2, 2012
    #3
  4. John

    John Guest

    On Mon, 2 Apr 2012 11:43:54 +0000 (UTC), Gordon Henderson
    <> wrote:

    >In article <jlbcd4$4ie$>,
    >David Woolley <> wrote:
    >>John wrote:
    >>> All in one phone/fax machine. If you switch to voip and use it
    >>> through an ATA, will the fax machine still work?

    >>
    >>If the ATA uses the same codec as the PSTN (G.711 A-Law in the UK) and
    >>the propagation delay is low enough, it should work. (G.711 mu-law
    >>should also work, at least as well as faxing to the US).

    >
    >It's not so much propogation (latency) as jitter and packet loss.
    >
    >Although I've demonstrated it working, I'd never give anyone any
    >sort of guarantees whatsoever of it working for real.
    >
    >>If it uses T.38 encoding of fax and regenerates the fax signal, it
    >>should also work.

    >
    >If you can find a provider that'll terminate the T.38...
    >
    >>If it uses GSM or G.729 without T.38, there is no hope.

    >
    >Indeed.
    >
    >Basically, it might work and if it does, then great, but doesn't
    >expect it to and use something else - e.g. email. What I have done
    >for clients in the past is ported their FAX number to a FAX to Email
    >service, then connected their legacy FAX maching to their standard
    >BT line for outgoung faxes (and make sure they withold the number
    >so people don't try to fax back on it) That seems to work fine when
    >people have a small number of FAXes to send, but still need to recieve
    >them.
    >
    >Gordon


    Thanks Gordon and David. It's not a major issue as very few faxes are
    sent, but was just curious as to whether it would.
    --
    John
    John, Apr 2, 2012
    #4
  5. Gordon Henderson wrote:

    >
    > It's not so much propogation (latency) as jitter and packet loss.
    >


    Propagation delay is important for some modem applications, because the
    modem handshaking has very tight time constraints for some applications.
    21CN is actually VoIP under the hood (so fax does work over VoIP), but
    some modems can no longer be used. I think this particularly affects
    ones in alarm systems.
    David Woolley, Apr 3, 2012
    #5
  6. John

    Woody Guest

    "David Woolley" <> wrote in message
    news:jlfbpl$d3c$...
    > Gordon Henderson wrote:
    >
    >>
    >> It's not so much propogation (latency) as jitter and packet
    >> loss.
    >>

    >
    > Propagation delay is important for some modem applications,
    > because the modem handshaking has very tight time constraints
    > for some applications. 21CN is actually VoIP under the hood (so
    > fax does work over VoIP), but some modems can no longer be
    > used. I think this particularly affects ones in alarm systems.



    21CN may be voip underneath but it is only a protocol and will be
    working over dedicated circuits.

    Voip for we mere mortals is through the Interweb will all its
    delays, routes, and anything else you can think of, so if it does
    work at all it may at best be unreliable and at worst produce
    cr*p.



    --
    Woody

    harrogate three at ntlworld dot com
    Woody, Apr 3, 2012
    #6
  7. Woody wrote:

    > 21CN may be voip underneath but it is only a protocol and will be
    > working over dedicated circuits.
    >


    I don't believe they are dedicated to voice. To me it only really makes
    sense if they share with the back haul circuits that support BT provided
    wholesale IP services, as well.

    The traffic will be prioritised, but that is also something that a
    competent network manager and a VoIP friendly ISP would do.

    > Voip for we mere mortals is through the Interweb will all its
    > delays, routes, and anything else you can think of, so if it does
    > work at all it may at best be unreliable and at worst produce
    > cr*p.
    >
    >
    >
    David Woolley, Apr 4, 2012
    #7
  8. John

    Stephen Guest

    On Mon, 02 Apr 2012 12:54:16 +0100, John
    <> wrote:

    >On Mon, 2 Apr 2012 11:43:54 +0000 (UTC), Gordon Henderson
    ><> wrote:
    >
    >>In article <jlbcd4$4ie$>,
    >>David Woolley <> wrote:
    >>>John wrote:
    >>>> All in one phone/fax machine. If you switch to voip and use it
    >>>> through an ATA, will the fax machine still work?
    >>>
    >>>If the ATA uses the same codec as the PSTN (G.711 A-Law in the UK) and
    >>>the propagation delay is low enough, it should work. (G.711 mu-law
    >>>should also work, at least as well as faxing to the US).

    >>
    >>It's not so much propogation (latency) as jitter and packet loss.
    >>
    >>Although I've demonstrated it working, I'd never give anyone any
    >>sort of guarantees whatsoever of it working for real.
    >>
    >>>If it uses T.38 encoding of fax and regenerates the fax signal, it
    >>>should also work.

    >>
    >>If you can find a provider that'll terminate the T.38...
    >>
    >>>If it uses GSM or G.729 without T.38, there is no hope.

    >>
    >>Indeed.
    >>
    >>Basically, it might work and if it does, then great, but doesn't
    >>expect it to and use something else - e.g. email. What I have done
    >>for clients in the past is ported their FAX number to a FAX to Email
    >>service, then connected their legacy FAX maching to their standard
    >>BT line for outgoung faxes (and make sure they withold the number
    >>so people don't try to fax back on it) That seems to work fine when
    >>people have a small number of FAXes to send, but still need to recieve
    >>them.
    >>
    >>Gordon

    >
    >Thanks Gordon and David. It's not a major issue as very few faxes are
    >sent, but was just curious as to whether it would.


    If you use Fax over VoIP where there is QoS on the access line (ie not
    just over a normal Internet feed) then the loss rate can be very low.

    But - that isnt going to be particularly cost effective unless you
    need that link for other things, and plain old analog voice is
    probably cheaper.....
    --
    Regards

    - replace xyz with ntl
    Stephen, Apr 4, 2012
    #8
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. NDB
    Replies:
    5
    Views:
    634
    news.dsl.pipex.com
    Jan 28, 2005
  2. Martin 53N 1W
    Replies:
    1
    Views:
    673
  3. Greg Alexander

    Cheap t37 fax machine (Fax over IP)

    Greg Alexander, Jun 14, 2005, in forum: VOIP
    Replies:
    2
    Views:
    4,659
  4. george

    free fax service, Fax online, Fax, Email fax

    george, Dec 26, 2007, in forum: Computer Information
    Replies:
    0
    Views:
    525
    george
    Dec 26, 2007
  5. Replies:
    0
    Views:
    583
Loading...

Share This Page