White board and Poll don’t work between Lync 2013 clients.
Desktop and application sharing between Lync 2013 clients work but White board or Poll don’t work with error network configuration problems etc…
During white board sharing if you run netstat on the client PC you will see the following:
netstat -ona | findstr 8057
TCP 10.XX.128.26:50656 10.YY.130.83:8057 SYN_SENT 4844
TCP 10.xx.128.26:50657 10.YY.130.83:8057 SYN_SENT 4844
here 10.XX.128.26 client trying yo connect to Lync 2013 FE server 10.YY.130.83 via port 8057. But the connection cannot be established and stays in SYN_SENT state for a while.
(4844 is the process id (PID) of lync.exe process)
There is a firewall between client subnet and Lync 2013 FE server. And TCP port 8057 is not open from Lync 2013 Client PC to Lync 2013 Front End Server. White board and Poll require connection Lync 2013 FE server’s TCP port 8057.
Open the following port on the Firewall:
Lync 2013 Client subnet
Lync 2013 FrontEnd Server
in Ports and Protocols for Internal Servers documentation (http://technet.microsoft.com/en-us/library/gg398833.aspx) TCP 8057 is listed in “Required Server Ports (by Server Role)” section but not in “Required Client Ports section” Although it must be.