An IP PBX is a complete telephony system that provides telephone calls over IP data networks. All conversations are transmitted as data packets over the network. The technology includes advanced communication features but also provides for significant worry-free scalability and robustness that all enterprises seek.

An enterprise does not need to disrupt its current external communication infrastructure: An IP PBX is able to connect to traditional PSTN lines via a VoIP gateway - so an enterprise can keep its regular telephone system.

With an IP PBX solution, the business owns and operates the equipment so an upfront capital investment is required to purchase the equipment and then there are on-going maintenance costs.

This is often better for larger businesses as the call control remains internal to the corporate network and a single wire can be routed to an office to provide both data and voice communications.