Introduction

The concept of voice over computer networks originated at the University of Illinois (USA). 1993 Charlie Klein released the word first program for voice over the network from a PC - Maven.

Information and communication technologies and services are now a key factor in the development of all areas of socio-economic sphere. The technology needs growing, it's leads to the invention of best ways for communication. As new technologies of interest to society and the business only if they lead to cost savings, as IP telephony has become widespread.

IP-telephony - Voice over IP-protocol (VoIP) - has long become a real tool for the job, business, and for many even became no alternative way to communicate with loved ones and colleagues. This is not only that place calls over the Internet, but the cost is much lower than the usual traditional tone, and sometimes even free. But also in this technology available other ways of communication such as video call.

The purpose of this work - the study of technology Voice over IP.