Bandwidth AND Memory

  • Chris

    Chris - 2007-12-09


    I am trying to get my mind around the bandwidth and memory requirments for DimDim. Can you tell me if my translation is correct? I realize that this is not exact science, but I am trying to build a calcualtion for minimum and maximum range.

    In the DimDim_specs.pdf document is says that " On a 1 CPU / 1 GB RAM server the maximum number of simultaneous sessions can be to a maximum of 500."  Can I safely estimate that the memory requirement is 2MB (1000MB/500 users) per user on average?

    A forum reply from Rajesh read "Regarding the bandwidth - Who ever starts or joins the meeting requires a minimum of 150 Kbps. It can vary, if you are doing audio/video along with Desktop sharing or application sharing. But only requirement related to bandwidth is a minimum of 150Kbps upload/download speed for both Presenter and Attendee." 
    I am confused about what that all really means in terms of monthly bandwidth demand. My math is as follows:
    ((150 kbps x 60 seconds x 1024 (to convert to bytes) x number of users 
    x number of minutes per month per user x number of days per month) /
    1048576)) to convert to Megabytes OR / 1073741824 to convert to

    So... in this example if I have 10 concurrent users at 10 minutes per 
    day for 20 days in a month it would be as follows:

    ((150 x 60 x 1024 x 10 x 15)/ 1073741824) would = 25.7 Gigabytes per
    These figures assume that the 150kbps is constant throughout the
    session for all users and the host.

    1)Can you please tell me if my calculations are accurate?
    2)Can you tell me if the kbps demand is just for starting the
    session or constant throughout the session? eg.
    If it is constant throughout the session. Can you give me your estimate ranges for the kbps that will be consumed per user.
    Just to have session open: 150-200 kbps
    Screen Sharing: 75-100 kbps
    VOIP: 30-50 kbps
    Powerpoint Presentation: 75 - 100  kbps
    Whiteboard: 50-100 kbps
    If it is not constant, can you tell me how I would calcualte/estimate bandwidth?
    Open Session: 100-125 kbps
    Screen Sharing: 100-200 kbps per refresh
    Powerpoint: 50-100 kbps per slide change
    Whiteboard: etc....

    Thank you very much for you help on this. I you can answer my questions, it will help a great deal.

    Thank you!
    Can you tell me factors increase or
    decrease kbps eg. Whitboard file sharing (50kbps??), Sharing my screen
    (200kpbs??) etc... and is the demand constant or just when the page is
    refreshed or turned...

    Thank you very much for your help!


    • Clint Davis

      Clint Davis - 2007-12-21

      Yeah i agree,

      Can we get a table to work out the data usage per feature. (As i want to disable the audio and video feature, and just uise the PPS, Chat, Desktop & Whiteboard)

      (Presenter & listener)
      Audio Per Person
      Video Per Person
      White board
      Powerpoint slides
      Desktop Sharing

      This way we can correctly calculate the average data costs


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