Voip Protocol

CHAPTER 1

INTRODUCTION

1. INTRODUCTION

1.1) INTRODUCTION TO THE PROJECT:

The Internet offers many services, e.g., e-mailing, instant messaging, bank accounting and file-sharing. Another service that is gaining popularity is Voice over IP (VoIP).

VoIP enables people to make phone calls, using the Internet for voice transportation.

The greatest benefit of VoIP over the POTS (Plain Old Telephone System) is that

expenses can be lowered incredibly. The reason for this, is that an Internet connection is increasingly more common and the cost for an Internet connection is decreasing. In addition, there is no cost associated with call establishment and there is no per minute rate. These factors make VoIP virtually free. Another advantage of VoIP is when a person moves, the VoIP phone automatically registers its new location, which makes VoIP transparent from this view.

Figure 1.1

A typical VoIP system is depicted in Figure 1.1 and an explanation of the parts

constituting this system is as follows:

• First, at the sender side voice sound is sampled using a microphone.

• Second, this voice signal is translated to a digital representation

by a D/A (digital-to-analog) converter.

• Third, this bit stream is packed into IP packets and sent along an IP network, which in most cases is the Internet.

• Fourth, at the receiver side these packets are stripped from IP and other headers. Fifth, these samples are put in a playback buffer. This buffer is needed to compensate for the variation of delay over the network, called jitter.

• Finally, an A/D (analog-to-digital) converter converts the voice data back into an analog signal.

Notice that most VoIP systems are two-way systems, therefore, the system must be replicated reversely.

The scope of our project covers:

The proposed system will be used by any organization, in order to minimize time to communicate and system cost, as well as to add flexibility to provide highly efficient performance, as it has the potential of cutting costs and making telecom services more affordable.

The scope of proposed system includes PC to PC connections using the public Internet as well as the Local Area Network.

1.2)