Microsoft has released the Skype for Business Cloud Connector Edition (CCE), now generally available for download. The download is quite small and for good reason - it is simply a process that kicks off the download of all the ISO files required to create the virtual environment.
To use the CCE, a dedicated Windows Serer 2012 R2 server is required (and yes, you must license the VMs so more than likely Data Center will be what you use or multiple Standard edition licenses). The installer will check to make sure you have the minimum required resources which. To plan for the hardware look to the planning guide found on TechNet here.
So while the CCE is free, there are a couple of paid requirements. One, you must have a SIP trunk on premise which you can connect to - a qualified SIP trunk or SBC - as control over the digits coming to and from the SIP trunk is limited (read E.164 expected/required). Two, one or more dedicated Hyper-V hosts (multiple if HA is required). Three, O365 licensed Skype users with Cloud PBX. The last point is a big one in that CCE will work ONLY in environments where there is no on premise Skype/Lync/OCS installed. This solution is designed for those that want to have Enterprise Voice in their O365 deployment but for whatever reason wish to use their on premise voice solution / plan / gateway.
The release of the Skype for Business Cloud Connector Edition opens up doors for those that cannot or will not license PSTN via O365 and remember, this is Gen1 so expect development and growth of the product solution as time moves on. Happy downloading.