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.
The figure below outlines a typical Business IP-PBX solution (courtesy of 3cx.com).
Business VoIP Service – Truly Revolutionary or a Gimmick
VoIP stands for "Voice Over Internet Protocol", which is a technology that allows you to make phone calls using your Broadband Internet connection instead of your regular phone service. It is also sometimes referred to as Voice over IP, Broadband phone, Internet phone service and Digital Voice. Yes, it is a marketing game by the different service providers but they all use the same core technology.
You still simply pick up your regular phone, dial a number and talk. VoIP is simple and is for everyone. It does not matter if the person you are calling has VoIP or not, this is all taken care of by your VoIP service provider.
The only requirement for this technology is a high speed Internet connection, such as DSL, cable, T1, etc. VoIP requires a bandwidth of up to 90Kbps depending on the voice compression algorithm chosen by the service provider. This is a higher bandwidth than dial-up Internet so a Broadband Internet connection is a basic requirement.