01-06-2012, 04:17 PM
VoIP IP-PBX
ABSTRACT
VoIP is a set of technologies that enable voice calls to be carried over the Internet (or other
networks designed for data), rather than the traditional telephone landline system—the Public
Switched Telephone Network, or PSTN. The potential for very low-cost or free voice calls is
driving the use of the technology but in the long-term, VoIP is more significant than just free
phone calls - it represents a major change in telecommunications. The fact that VoIP
transmits voice as digitised packets over the Internet means that it has the potential to
converge with other digital technologies, which in turn will result in new services and
applications becoming available. However, the adoption of VoIP is not without
complications. The traditional PSTN telephone infrastructure has been built up over the last
one hundred years or so and has developed into a robust voice communications system that
provides reliability figures of nearly 100%. In contrast, VoIP is a relatively new technology
with a fledgling architecture that is built on inherently less reliable data networks. This
means that there are therefore justifiable concerns around the extent to which it is deployed.