In simple form:
Computers + Internet + Mobile Technology + PBX = virtual PBX systems or IP PBX systems

Computer telephony integration, also called computer-telephone integration or CTI, is technology that allows interactions on a telephone and a computer to be integrated or co-ordinated. As contact channels have expanded from voice to include email, web, and fax, the definition of CTI has expanded to include the integration of all customer contact channels (voice, email, web, fax, etc.) with computer systems
The origins of CTI can be found in simple Screen Population (or "Screen Pop") technology. This allows data collected from the telephone systems to be used as input data to query databases with customer information and populate that data instantaneously in the customer service representative screen. The net effect is the agent already has the required screen on his/her terminal before speaking with the customer . This technology started gaining widespread adoption in markets like North America and UK/Northern European countries
Among the key players in this area, Lucent played ...more