Skype Screen Sharing fails with Zapp Tunnel mode

(GANESH KRISHNAN) #1

My screen sharing start with Zapp in tunnel mode and fails within 3 to 5 seconds stating “There is trouble in sharing”. I suspect whether Zscaler firewall might block and UDP ports. But Screen sharng works fine with Zapp tunnel with local proxy and PAC file.

(Thomas Quinlan) #2

Hi Ganesh,

Tunnel mode forwards 80/443 traffic through an HTTP Connect tunnel to Zscaler. TwLP mode sends all traffic from the browser & proxy-aware applications to the local proxy (on port 9000) before deciding what to send to Zscaler, so from the sound of it, Screen Sharing is sending traffic on a non-standard port that is being captured by TwLP that isn’t captured via Tunnel.

Out of curiosity, is this Skype for Business or standard consumer Skype?

(GANESH KRISHNAN) #3

We use Skype for Business. Doesn’t tunnel mode send everything to Zen. TwLP will sent anything from browser and browser based application to port 9000

(Thomas Quinlan) #4

Hi Ganesh,

Tunnel mode only sends web traffic on ports 80 and 443. There are plans around the different modes for version 2.0 of the Z App but these are still being tested and no guarantees as to function and/or dates can be given at the moment. (Safe harbour, etc.)