some questions about VBSS

[David Phillips]

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 vbss drop out to rdp at random times and stay that way for the entirety of the meeting.  Also, I thought the iOS client supported vbss?  It seems when we join from the SfB iOS app on an iPad, frame rate for everyone really drops.

[#2]

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. 

[#3]

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?

[#4]

*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)

[#5]

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