Restaurant router its a Mikrotik (don´t remember model), but I know it has an static mikrotik propietary IP. and almost sure it works with PPTP. Home router is an Asus RT-AC66U, that now it also supports PPTP. But no Static IP, just DDNS. I think both also support OpenVPN. Not sure about actual differences, long ago since my last VPN configuration. Any suggestion?.