128Kbps channel on VOIP?

Discussion in 'VOIP' started by Scott, Oct 20, 2003.

  1. Scott

    Scott Guest

    I am trying to transport 128Kbps data over VOIP. Is this possible?
    Is there a standard applicable to this effort? I realize that the
    G.711 rate is 64kbps, so it would be just like transporting two
    regular G.711 channels. The problem would be splitting up the 128Kbps
    and then resynchronizing the two on the other end. Thanks for any
    help.
     
    Scott, Oct 20, 2003
    #1
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  2. Scott

    Miguel Cruz Guest

    Isn't G.711 lossy? You get less data back out than you put in.

    How about trying the revolutionary new technology: DoIP (Data over IP)?

    miguel
     
    Miguel Cruz, Oct 20, 2003
    #2
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  3. Scott

    root Guest

    I thought so. Otherwise, one could have attached a FAX machine to the VoIP
    device only for voice.
    I thought that's what UDP is all about -- to transfer data over IP.
     
    root, Oct 20, 2003
    #3
  4. Scott

    MM Guest

    Isn't that DIP for short..?
     
    MM, Oct 21, 2003
    #4
  5. Scott

    Miguel Cruz Guest

    Oops, my mistake.

    miguel
     
    Miguel Cruz, Oct 21, 2003
    #5
  6. Scott

    Neil Smith Guest

    Isn't UDP potentially lossy as well ? Better stick to TCP for fax
    data or you might lose that important signature ! BTW do www.tpc.com
    still do email to fax services ? Might be worth a try for low volume
    fax data.

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    Neil Smith, Oct 21, 2003
    #6
  7. Scott

    root Guest

    Oops, my mistake, too.
     
    root, Oct 21, 2003
    #7
  8. Scott

    Scott Guest

    Thanks, but I have no choice...The protocol I must use is VOIP. The
    data to transport is actually voice, but at 128Kbps. I was just
    saying that somehow this stream must be split into two 64kbps and then
    reassembled...I just wondered if VOIP has support for 128Kbps audio.

    Scott
     
    Scott, Oct 21, 2003
    #8
  9. Scott

    Miguel Cruz Guest

    VoIP isn't a protocol, it's an open-ended set of technologies. I am sure you
    can find a codec that wants 128K.

    It is entirely unclear to me what the real restriction is that you are
    facing. Why "must" you use VoIP? Without an answer to that question
    (basically, a description of your connectivity environment) nobody can help
    you much.

    miguel
     
    Miguel Cruz, Oct 21, 2003
    #9
  10. Scott

    MM Guest

    UDP is not lossy. G.711, like the MP3 audio format, takes an audio
    stream and creates an approximation of that stream that requires less
    bandwidth to store or transmit. Once this process is done, it can't be
    undone. That is, there is no way of recreating the original audio stream.

    UDP does not alter the data passed to it by an application. It differs
    from TCP in that TCP sequences the data and requires acknowledgement of
    receipt of that data. If a piece of data is lost, the TCP protocol will
    detect this and request that the data be retransmitted, completely
    transparent to the application. The cost of doing this is larger
    packets due to overhead, plus more traffic due to the acknowledgements.
    UDP just ships out the data without sequencing or acknowledgements.
    It is up to the application to detect and retransmit data. If an
    application that uses UDP loses data, it's the fault of the application,
    not the tranport protocol.

    MM
     
    MM, Oct 22, 2003
    #10
  11. Scott

    MM Guest

    It was supposed to be a joke!

    MM
     
    MM, Oct 22, 2003
    #11
  12. Scott

    Guest Guest

    VoIP is Voice over Internet Protocol. If VoIP is not a protocol, then why
    there is a P on VoIP?
     
    Guest, Oct 22, 2003
    #12
  13. Because it's Voice over (Internet Protocol), not (Voice over Internet)
    protocol.

    He's right, it's just a set of technologies.
     
    Phil McKerracher, Oct 22, 2003
    #13
  14. Scott

    MM Guest

    Speaking of DIPs...
     
    MM, Oct 22, 2003
    #14
  15. Scott

    Miguel Cruz Guest

    I know, I was just acknowledging that your joke was better than mine.

    miguel
     
    Miguel Cruz, Oct 22, 2003
    #15
  16. Scott

    Miguel Cruz Guest

    It's Voice, over something called "Internet Protocol".

    This works the same way that a "Coney Island hot dog" is not a dog.

    miguel
     
    Miguel Cruz, Oct 22, 2003
    #16
  17. Scott

    Neil Smith Guest

    On Wed, 22 Oct 2003 06:12:25 GMT, (Miguel Cruz) wrote:

    Or the same way George Bush is not - - - oh, wait, damn ....
    Well I can dream

    LOL
    ========================================================
    CaptionKit http://www.captionkit.com : Produce subtitled
    internet media, transcripts and searchable video. Supports
    Real Player, Quicktime and Windows Media Player.

    VideoChat with friends online, get Freshly Toasted every
    day at http://www.fresh-toast.net : NetMeeting solutions
    for a connected world.
     
    Neil Smith, Oct 22, 2003
    #17
  18. Scott

    shope Guest

    i was in a cisco presentation when they mentioned that their phones support
    256 Kbps for better than G.711 audio.

    FWIW there are lots of standards in the broadcast industry for audio codecs
    at better quality levels - some of it gets used for audio feeds over ISDN
    for football reports and so on.
     
    shope, Oct 22, 2003
    #18
  19. Scott

    Hank Karl Guest

    is that H.323, SIP, MGCP/Megaco, or what?

    G.722 compresses 7K audio to 64K (or 56K or 48K). Other codecs will
    compress this 7K to 16K. what type of codec uses 128K?

    You can probably select your codec, most of the VoIP signaling
    protocols allow you to do so.
     
    Hank Karl, Oct 22, 2003
    #19
  20. Scott

    chris Guest

    Note quite like MP3, where it uses a lossy compression method. The
    G.711 codec doesn't compress or alter the 'digitized' data. The loss
    actually occurs when you sample the analog data stream (8bit, 8kHz
    typically for voice).

    Also, it's kinda pointless to use TCP for realtime data because if a
    packet isn't delivered on time, you can't use it. The Cisco fax relay
    protocol still doesn't use TCP, but rather sends the same packets
    twice to provide redundancy.

    -Chris
     
    chris, Oct 23, 2003
    #20
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