Virtual Modem for VoIP

Discussion in 'VOIP' started by donfanning, Mar 11, 2005.

  1. donfanning

    wkearney99 Guest

    Given how cheap ATA devices are it seems like a fools errand to bother.

    So, you're effectively talking about having a PC with a modem "call" into
    this device, route it through a VoIP circuit and then dial-out again at the
    remote end to connect to a remote BBS modem? Or, skipping the modem on the
    source end, let the PC use a remote FXO interface as an outbound dialing
    modem to the BBS. Sort of a tunnel for modem dialing? Isn't this what
    terminal servers are for? Using VoIP seems like it would add an unnecessary
    degree of complication to it.

    Besides, BBS and modems? How LAST century...

    (this from a guy who actually had and used 300 baud devices once upon a

    -Bill Kearney
    wkearney99, Mar 14, 2005
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  2. donfanning

    wkearney99 Guest

    The virtual modems out there are for translating COM/Serial
    There's nothing on google for all sorts of things. Sometimes because
    nobody's done it yet. Often because most know better than to bother wasting
    time on it.

    Shiva's old series of NetModem devices come to mind when I think about
    remote modem use. A client on the PC/Mac would tunnel through the local IP
    network to the NetModem and then dial-out.

    What problem, specifically, are you trying to solve? More and more it
    doesn't seem like VoIP has any use in this situation.
    wkearney99, Mar 14, 2005
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  3. donfanning

    Rick Merrill Guest

    I for one will not argue with the kook, ok?
    Rick Merrill, Mar 14, 2005
  4. donfanning

    Rick Merrill Guest

    (I still have one that also does 110 baud...)
    Rick Merrill, Mar 14, 2005
  5. donfanning

    Ivor Jones Guest

    That's nothing, I used to have a Creed 444 on 50 baud RTTY :)

    Ivor Jones, Mar 14, 2005
  6. donfanning

    donfanning Guest

    The DSP would be the source (or emulated modem).
    --through VoIP--
    Talking to a real modem on the destination.


    It's not LAST century when you consider how much of the world still
    isn't on broadband.
    Including all those myrad FAX machines, this would be something of a
    killer application.
    donfanning, Mar 15, 2005
  7. donfanning

    donfanning Guest

    A Shiva netmodem would be great as an OUTDIAL device hooked to your PBX
    with a TELNET port into it.


    The problem is that I want to use a program to call out using my
    existing soundcard and say connect to a remote system. Be it a ISP
    indial, a VPN indial, a BBS indial, a FAX machine indial or even
    reverse it so that when someone calls my VoIP POTS number, it connects
    to my modem and provides modem/fax telephony without the hardware hit
    (meaning an ATA).


    Think of it this way... back in the day, hackers would be able to
    wardial systems via modem. With current technology you have to use an
    ATA to accomplish the same method. This just saves the trouble of an
    ATA. Better yet, think of a built-in FAX capability right into your
    VoIP without the need to subscribe to a IP-Based FAX network. Get my
    donfanning, Mar 15, 2005
  8. donfanning

    donfanning Guest

    Tests have proven that VoIP can tolerate speeds up to 14.4 better than
    80%. Technically I don't require that speed. 2400 is more than
    donfanning, Mar 15, 2005
  9. donfanning

    Miguel Cruz Guest

    Do you understand how much loss there is in that extra D/A and A/D? It's
    just not worth it.
    Not much of the world is interested in highly erratic 9600bps data service,

    There were companies doing what you propose in the past (though they did it
    the right way, by doing the modulation/demodulation at the
    phone-company-interface end, not at the originating end). To the best of my
    knowledge they have all shut down due to lack of consumer interest.
    There are already endless fax delivery services, again, all of them doing it
    the smart way, not the backwards and inefficient way you are proposing.

    There's even a free one with decent coverage:

    Miguel Cruz, Mar 15, 2005
  10. donfanning

    donfanning Guest

    MWave and DSP's are the shortest route to the solution just because
    they were able to emulate the sounds and belches that a modem makes
    through software. A modern day SoundBlaster Audigy (or similar) has
    100x the DSP computing capability than that DSP had.
    There's no mixing examples. I give the MWave and DSP as an example of
    technology that has already been created however is currently not in
    production anymore. A more viable solution should be out there to
    solve this issue being MODEM/FAX telephony over VoIP without the use of
    an ATA which seems REDUNDANT if your soundcard is more than capable of

    (apologies in advance for the excessive use of caps)
    donfanning, Mar 15, 2005
  11. donfanning

    Miguel Cruz Guest

    Where are you calling? Minutes in the USA are about 1 cent. How much effort
    will you put into this, and how could it possibly be worthwhile?

    Let's say you put 40 hours into sorting your scheme out, and you value your
    time at $50/hour. In order to break even you'd need to use 200,000 minutes
    of connectivity time. That's 4 hours a day, 7 days a week, for over two
    years. It's just a losing proposition from start to finish.

    Miguel Cruz, Mar 15, 2005
  12. donfanning

    donfanning Guest

    Heh... Personally I'm thinking in terms of backwards compatibility but
    Commercial viability:
    Sure there were services like Sprint's PCPursuit or BT Tymnet's service
    however your right... both services went the way of the dodo on X.25
    networks (too bad really... personally I think there needs to be a
    revival of modem outdial services)

    All things being equal, this is truly more of a hobbiest tact than a
    multi-million dollar venture capitol setup.

    If I were a BBS operator (which I'm debating on actually), I could have
    people TELNET into my system. What's the fun in that? Not only do
    terminal programs such as QModem not work over IP but my BBS has to
    have a TCP/IP stack loaded into the stack before it talks to FOSSIL and
    then talks to the BBS program which may or may not work.


    A VoIP replacement of a Virtual Modem complete with AT command set
    would enhance the usability of the technology and make the entire
    system truly universal. It wouldn't matter if they were on the net or
    not as using the appropriate software, they could connect to my
    'virtual' modem pool and connect in (or even from VoIP indial).


    As for whether or not analogue modem service is a viable or interesting
    proposition, tell that to the millions of people who already have
    dialup services but lack ISP services for some reason (or are unable to
    get broadband which is the only way VoIP even truly works). I think
    there is a extreme interest in keeping compatibility with existing
    technologies in a more digital fashion.


    Fax services... Tho there are delivery services out there, what would
    be the point of putting it on my business card if I have a computer
    capable of FAX modem telephony? All I'm trying to do is remove the
    middleman which is the ATA from digital communications (including data
    and fax modems). I have nothing against buying ATA's for the bedroom,
    the garage or even the guest bedroom but spending $50US a pop on a
    telephone line extension seems extreme when you consider all the POTS
    technology at hand (again not against spending the dough, but I prefer
    to keep digital digital and remove some of the clutter).

    Sure there are indial services but you take vonage for example. You
    have to pay extra just for them to assign you a fax telephone number.
    Seems to me if my computer is sitting online all the time anyways, it
    could receive the FAX without the need for an extra telephone line or
    the ATA it would sit behind.
    donfanning, Mar 15, 2005
  13. donfanning

    donfanning Guest

    Compared to POTS telephone lines, seems pretty fair to me.

    Plus it would give more incentive to digitally minded people to setup
    Asterisk servers and link their telephone lines up.

    Unfortunately, my cash poor ass can't set one up right now. However,
    if I do, I'll do it the right way and hook up a cell phone base to the
    FXO so it can call out on my "any-time" minutes or unlimited nights and
    weekends. :)
    donfanning, Mar 15, 2005
  14. donfanning

    Miguel Cruz Guest

    To do what with?
    These are much easier problems to solve, and if people cared, they would
    I really don't understand who would want to.
    To be honest, the only people I have ever heard of using dialup modems for
    anything other than the internet in this day and age fall into a few
    categories, none of whom would be better served by a low-speed,
    high-maintenance-overhead national outdial network:

    1) alarm services - almost always local calls.

    2) devices like TiVO - they contract with indial networks so they're local
    calls for almost everyone. Surely the reach of those networks is broader
    than anything you could create given the limited demand for an inferior
    version with low data rates and bad connection quality.

    3) telesensing - usually local calls, otherwise the tiny cost of
    long-distance is easily justified, and in any case reliability is more
    important than cost.

    4) fax - sending a fax long-distance costs about 5 cents per page or less.
    Anyone who sends in enough volume to care will have contracted with a
    nationwide fax delivery service.
    You don't need one ATA per extension (if you're talking about extensions in
    the sense that people normally think about in a home), just one per line.
    You can get a free fax number from

    Miguel Cruz, Mar 15, 2005
  15. donfanning

    donfanning Guest

    Too bad the pessimistic has reigned.
    Sure people care. You're only thinking of the here-and-now
    applications. Your not even thinking of the MILLIONS of other
    applications that take place that you don't even know of.

    CC/ATM machines all use modems to communicate to the mothership
    Auto Parts, Car Sales etc... all use dial-up modems to communicate to
    their respective databases to check parts availability (unless it's a
    major chain).
    Of course there is telesensing, but it's easier for them to use GPRS
    technology without the need for wires.
    Plus the million of other applications that go on every day without you
    even realizing it. Go to your grocer and walk up to their customer
    service desk. I bet there's a system there... called Western Union.


    As for reliving the hayday of modern digital telecommunications...
    you're just not seeing the bigger picture. I guess living in a world
    where the only thing you've ever know is WWW. something would taint
    that. Me, being from the 01d 5k00l, yearn for a time where I didn't
    need to have 10 million graphics bombarding me just to check email or
    being able to QWK packet all my email and news up so I can review it
    off-line at my leisure. There is viable applications to all the
    techniques back then. Previous it was the cost of telecommunications.
    Now it's the RELIABILITY of communications. Why reinvent the wheel
    when we can make the wheel more common. Seems to me that a Virtual
    Analog Modem is exactly what the doctor is ordering to ensure
    application compatibility in the time where no dialtone will sound.
    donfanning, Mar 15, 2005
  16. donfanning

    Miguel Cruz Guest

    And there's no compelling argument for them to sacrifice security,
    reliability, and speed for the sake of saving 1 cent per transaction.
    You're talking to the wrong guy. I've got a collection of acoustic couplers
    going back to when they were the size of a big-city yellow pages. I fondly
    remember the days before CRTs were affordable, when upgrading from a
    round-key teletype to a DECwriter was like stepping onto the set of Star
    Trek. I use text-only tools for mail and news (wouldn't catch me posting
    from MSN) and you couldn't pry me away from the command line for 90% of the
    tasks I do.

    But I do recognize when something changes for the better, and fungible data
    transit over IP is so much better than point-to-point D-A-D in so many ways
    for almost everything that it's not even funny.
    It's anathema to reliability. You are adding extra layers of translation,
    conversion, bits of hardware, delay, and entropy, for no conceivable gain.
    What starts as data should stay as data. To convert it to noise, convert
    that noise back to bits, convert those bits back to noise, and convert that
    noise back to bits one last time is the height of pointless friction.

    Miguel Cruz, Mar 15, 2005
  17. donfanning

    donfanning Guest

    Considering that the data is in fact digital going between MARK and
    SPACE in a modulated dance of data within your internal system (no
    noise) into a SIP phone (no noise again) to an outgoing VSP where upon
    it might gain line noise on the POTS end, seems pretty digital to me
    all the way through.

    IP has WAY too much overhead. Nevermind layers, this is all LAYER 3
    stuff anyways, the audio packet rides on top of an UDP packet therefore
    may introduce noise from dropped packets it still seems to me that
    there is a viable need for it.

    Doesn't matter if you came from the day of accoustic couplers (believe
    me, I've had mine as well), the most you probably did was talk to the
    university's PDP. I'm talking about real users from the home computer
    revolution that connected to BBS's and the like to transfer
    information. Oh sure, there were biffed characters in the data stream.
    That's why protocols for file transfer were created (ala XMODEM,
    KERMIT and Zmodem). But the fact is that these systems were able to
    carry data long before IP was commonplace.

    I remember when I was in college, all three of our major universities
    were tied into a single 56k data line. 10 years later, all three of
    the universities are now OC-48. Sure technology changes, but that's no
    excuse for wantonist and wasteful use of data resources. I see better
    applications for bandwidth like IP-Television. ;)

    At this point we'll just agree to disagree. I still see quite the
    viable need for an Analogous Virtual Modem that travels over VoIP.
    When the architecture is truly unobtrusive and ubiquous, when my fridge
    can stay stocked by itself via online shopping, when I can connect to
    any system in the world (on the Internet or not) without changing
    transport medium, then it's a new world. Till then, we need to keep
    the wrenches turning.
    donfanning, Mar 15, 2005
  18. donfanning

    Ivor Jones Guest


    I'm not sure I want my fridge doing my shopping for me..!

    Ivor Jones, Mar 15, 2005
  19. donfanning

    donfanning Guest

    donfanning, Mar 15, 2005
  20. donfanning

    Franc Zabkar Guest

    Sometimes low tech is faster than high tech.

    Wi-Fly and TCP (Transmission by Carrier Pigeons):

    - Franc Zabkar
    Franc Zabkar, Mar 19, 2005
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