TRAFFIC OVERHEAD AND VOICE COMPRESSION IN VOIP

Traffic Overhead and Voice Compression in VoIP Applications

Table of Contents

CHAPTER I: INTRODUCTION TO VOIP TELEPHONY3

Introduction3

Public Switched Telephone Network3

Switching3

Routing4

Connection Hierarchy5

Telephone numbering5

Signalling6

Packetization and Packet Switching7

Addressing8

Routing and forwarding9

Performance Issues in the internet11

Latency11

Packet Loss11

Jitter12

Quality of Service (QoS)12

CHAPTER II: LITERATURE REVIEW15

VoIP15

Packetisation18

Network Technology20

Network Architecture22

CHAPTER III: VOIP CODECS24

Introduction24

The Codec's Role in a Phone Call25

Comparing Codecs26

How the Codecs Compare27

Summary34

CHAPTER IV: LITERATURE REVIEW ON SIP, RTP & H.323 PROTOCOL36

SIP Protocol36

RTP Protocol39

H.323 Protocol42

Summary45

REFERENCES46

CHAPTER I: INTRODUCTION to VoIP TELEPHONY

Introduction

Voice over IP clarifies the carrying of Voice over IP supported networks. VoIP is a booming understanding now a day's repairing our prevailing usual phone understanding referred to as public interchanged phone web (PSTN). Voice over IP (VoIP) is a understanding that sanctions you to generate voice calls employing an World Wide Web connection. In this understanding, analogue audio indicators are modified into digital particulars and diagrams that can be transferred through the World Wide Web employing the Internet Protocols. VoIP is in supplement referred as IP Telephony, Internet telephony, Broadband telephony, Broadband Phone and Voice through Broadband. Before overseen in particulars of VoIP Technology, we take a condensed look   at telephony in the PSTN space. The purpose of this component is to give a conceptual prediction that went by car the bring forth of the telephony web and in supplement to lay a foundation to the fashion of services that ought be foretold on a VoIP network.

 

Public Switched Telephone Network

A PSTN in other expressions phone web which communicates voice through a bound augmentation where the calls are routed through interchanges is the minimal telephony technology. Connecting a call in PSTN estimates a interchanging understanding to road the placement toured to of the calls.

 

Switching

            The first of all concept behind is to exercise multiple handsets to portion the row on an on-demand foundation after it is idle. So that it rejects the charge of deployment. In correct, the context of multiplexing was used. But, the drawback was that if couple couples of handsets were disseminating a solitary row, simply one couple of them could reverse a time. On the reverse for instance, the phone bring forth can do with simply one row as an alternative two.

            While disseminating of a row was resolutely a gratifying awareness, the whole spun line could not be dispersed end-to-end since its endpoints are couple of the handsets dwelling at assorted locations. This handed out to the thought of segmenting the end to end spun line into minor elements and realizing the disseminating good sense into these pieces.  The invention that bound these elements is a switch. As Technology very complex, these interchanges are automated and were masterful to change numerous calls simultaneously. The interchanges today are electric-powered propelled invention and very take on at their venture where authorities hundreds of calls simultaneously.

 

Routing

             As it was not feasible to bind all the handsets in the whole environs (State, nation, world) to a solitary change, multiple interchanges are employed corresponding to assorted geographical regions.  Hence the greater the way greater the diagram ...