DCS Telecom Tips on Choosing The Right Telephone Systems For Y | Page 3

Understanding the Basics of
PBX, IP PBX, VOIP Phone
 PBX
 PBX stands for Private Branch Exchange. PBX describes the system within an
organisation or company that is used to forward calls to the correct person or
department.
 In the past, PBX was done manually by staff physically connecting two phones
with a cable (referred to as switching). An operator would answer, ask the caller
who they needed to speak to, and then connect the call.
 IP PBX
 With the invention of the Internet, IP (Internet Protocol) PBX became possible. This
involves using a computer on the Internet to transmit calls and using a serial
connected (usually USB) phone or headset to listen and talk. The signal is
converted from analogue to digital in order to transmit over the IP network and
then converted back to be played as audio on the other end.
 VoIP
 VoIP (Voice over IP) is very similar to IP PBX in that it uses networked devices with
IP addresses. However, VoIP systems are usually cloud-based as opposed to
having a locally hosted server. While this provides greater mobility at lower cost,
it requires very fast, reliable Internet. In the event of a power outage or loss of
Internet, no communication is possible.