Had a proud moment yesterday in my home lab build, all the hardware is fairly basic - Intel i5 NUC (do have a threadripper rig but it's not exactly power efficient!) and Draytek router are important bits of hardware. Built up an AD, Exchange 2016 and Skype for Business 2015 environment. Finally got around to finding a "good" SIP trunk provider (Gamma - ~£90 setup, ~£9 a month for two trunks and 10 DDI's) and installing Audiocodes Mediant gateway (virtualized edition - which is free for 3 concurrent calls!!) and got inbound and outbound calls working. Next step is to setup the SfB conferencing, outlook integration, external access and endpoints (Polycom vvx, SNOM and Spectralink DECT). Really enjoyed setting it all up, albeit with some swear words thrown in. What you got?