[VoiceOps] IP PBX to Interface with Hospitality Interface

Hi all, We are looking for an IP PBX with an interface to an Agilysys Hospitality system. The original solution we had quoted nearly 8 months ago is no longer available so we are scrambling to find an alternate solution. Does anyone have a PBX that they have had good experiences interfacing to Agilysys? A solution to be deployed on Linux would be preferred, but any recommendations that people have found to be reliable would be welcome at this point. Tim Donahue