The Voice over IP is a technology  which has been used for several years. Its development was principally on  the perspective of cost  reduction   .

 The phone cost for a company can be significantly reduced with the use of the Voice over IP,  particularly in the case of communications between sites which are distant from the company, international calls and numerous long-distance calls …

 The multiplication and  internationalisation of  economic actors and  partners of  the company, the delocalisation of services or units, has increased the need of distant communication and thus there is the need to master the costs of communication using the telephone .

One of the assets of the Voice over IP is its simplicity to manage. Also the actual necessity to control two networks independently ,  one for the voice, and the other  for the data. The Voice over IP simplifies the task of managing and maintenance of the company's networks.

Finally, the Voice over IP opens the door to future technologies and the services  associated with   the evolution of  email ( the unified communication) …