Video Interop Server (VIS)
VIS is a standalone server role implemented in on-premises deployment and
provides interoperability with Cisco/Tandberg Video TeleConferencing endpoints (VTC) in this release. (Potentially,
other systems will be included in future releases). VIS acts as B2BUA between SfB
deployment and Video Gateway (CUCM). 
Microsoft has re-branded Lync 2013 Client as
Skype for Business (SfB) Client and released that update on 14 April 2015. It
will rebrand next version of Lync server as Skype for business (SfB) server
2015 and will release officially it on 1 May 2015. This article’s objective is
to explain what new features it brings along.
Skype for Business: What’s New
