Ubiqcom VoIP products are compatible with all IP-PBXs that support the open SIP platform. Ubiqcom also verifies that our VoIP products interoperate with particular IP-PBXs without pursuing official certification. Ubqicom performs rigorous in-house testing of our products with IP-PBXs, and through such testing we are able to verify interoperability. Ubiqcom P-52 Phone is best in its range and too good in quality.