VOIP : The Voice over IP Concept

The Voice over IP Concept

The IP-PBX is a new type of PBX. Here speech is not routed over a separate infrastructure.
Instead, it’s an integrated component of a common infrastructure for speech and data
communication in a multimedia network.

The packet-oriented and connectionless communications protocol IP (Internet protocol) is
fundamental for linking these infrastructures. With the rapid development of the internet, IP
has become very important in the world of communications. Speech is compressed, wrapped
in IP packets and simultaneously transported on the same network along with other data.
If speech is transmitted, the bandwidth of the data-network is used only partially. As audio
and video data are transferred by IP, this is often referred to as IP telephony or Voice over IP
(VoIP).

IP-PBX itself is a software kit running usually on a server in the LAN. This kit controls all
dialling and connection processes inside and outside of the local multimedia network. The
most important advantage of an IP-PBX is the fact that no special switching hardware is
needed. So, unlike a classical PBX, there is no switching network. The IP-PBX provides the
switching functionality of a PBX simply by assigning IP addresses and substation numbers to
the IP telephony devices. These are linked to the LAN and coordinate the connection
requests. So IP telephony can take advantage of the advanced and established routing and
network technology of IP networks.