PBX (Private Branch Exchange) is the system in your company that connects individual desk extensions to external telephone lines and mobile networks.
A SIP-enabled PBX is a PBX that can connect to the internet and use the SIP protocol to make calls over the internet.
We recommend that you use a Skype Connect™ certified PBX as we cannot ensure all your SIP-enabled PBX features and functions will operate correctly in non-certified SIP-enabled PBXs when used with Skype Connect.
For the current list of Skype Connect certified SIP-enabled PBX vendors, follow this link and click Compatible phone systems.
For more information, go to What is Skype Connect™ and how does it work?