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David Phillips's avatar
David Phillips
Steel Contributor
Jun 26, 2017

some questions about VBSS

Hi  everyone, Are there other factors besides someone joining a meeting with a vbss-unsupported client or remote controlling that would drop screen sharing from vbss to rdp?  We have full desktop ...
Desktop Client
Brandon Long's avatar
Brandon Long
Brass Contributor
Jun 26, 2017

There are other factors:

-Presenting Program instead of desktop

-Conferencing End Points (Room Systems that don't support VBSS)

-Reg Keys (All it takes is 1 attendee to be restricted)

[HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Lync]
"EnableConferenceScreenSharingOverVideo"=dword:00000000

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\16.0\Lync]
"EnableConferenceScreenSharingOverVideo"=dword:00000000

 

And remember, Once the session falls back to RDP, it won't renegotiate up to vbss unless someone reshares. 

  • David Phillips's avatar
    David Phillips
    Steel Contributor
    Jun 26, 2017

    Thanks for your response Brandon.  None of those factors were in play.  For example, an endpoint that joined during a succesful test joined later and caused the session to drop to RDP.  Does available bandwidth or network issues cause a VBSS session to drop to RDP?

    • Brandon Long's avatar
      Brandon Long
      Brass Contributor
      Jun 29, 2017

      *Also can't share higher than 1080 resolution over VBSS :)

      *Recording the meeting will trigger RDP

       

      Any chance that there's a layer 7 (Application Aware) firewall in the equation?

       

      I don't have any definitive answers but I'm thinking something in the network is changing:

      1. Bandwidth (I can't find anything that states that Skype renegotiates to RDP when packets start dropping but it would make sense as RDP uses less bandwidth)

      2. Firewall starts blocking the UDP stream (Palo Alto's are notorious for this) and Skype switches to TCP. (VBSS requries H.264UC viaUDP)

      • Edgar Mauricio Garantiva Ortiz's avatar
        Edgar Mauricio Garantiva Ortiz
        Copper Contributor
        Aug 24, 2018
        Hi Brandon, about the second point that you refer , do you know any documentation or workaround for avoid a blocking UDP Stream for VBBS at Firewall (like PaloAlto) ? Maybe there is a tool like "Skype for Business Network Assessment Tool" for testing VBSS specifically? https://www.microsoft.com/en-us/download/details.aspx?id=53885