First the infrastructure:
1 Kemp NLB (free edition) (DMZ)
2 Skype for Business edge (DMZ)
3 Skype for Business front-end (server-network)
1 Sesionhost with Skype for Business Client (client-network)
We configured the Kemp NLB for the edge server (SIP, AV, Conferencing, XMPP) according to the recommendations.
The skype edge are communicate directly to the front end.
It is not possible to use desktopshare or filetransfer from sessionhost to external or external to sessionhost. If we bypass the Kemp NLB or only have one skype edge online (the other server are disabled in the nlb) it works.
External to external and sessionhost to sessionhost is no problem.
Is there any known issue?