Book Title:	Introduction to IP Telephony: Why and How Companies are Upgrading Private Telephone Systems to use VoIP Service
Author:	Lawrence Harte
Publication:	Althos Publishing 2003
ISBN:	B00009RB1D

Book Review: Introduction to IP Telephony

The history of interactive communication is not that large a subject: more than 30 years ago telephones were the only really way of communicating in real-time, Internet did not exist, video was only broadcast by the TV stations. Now, the computer has gained an important part in our lives and communication has become much easier and more low cost than by regular, PSTN phone.

A new direction was noted when the classic phone line technology, combined with the advantages of transforming analog voice signals into digital ones, was integrated with the internet infrastructure providing for new possibilities. One such field is VoIP – Voice over IP, that proposes communication using the Internet infrastructure, by digitizing voice data and sending it as packets through the existing IP services. This could mean great distance communication at low costs, and features that the computers can provide, such as multimedia exchange, multiple callers at one time, security via encryption and so on.

However, communication must be a real-time process, and unfortunately the current state of the Internet infrastructure is not suitable for VoIP without some adjustments. Therefore there are cost and quality tradeoffs that can be reduced using some of today’s standards and proprietary hardware, as well as risks and benefits that need to be understood in order to have a successful deployment of VoIP solutions in the corporate world.

Introduction to IP Telephony is a good introduction into VoIP Services for specialists in telecommunications that want to shift to IP telephony. It explains how and why VoIP can reduce companies telecommunication cost as much as 70%, while integrating some of the advantages of Internet communication to the regular PSTN lines. The book is financially oriented, showing how revenues can be increased through linking Internet information systems to the telephone systems and order processing automation.

Introduction to IP Telephony: Why and How Companies are Upgrading Private Telephone Systems to use VoIP Services explains the quality tradeoffs VoIP systems often imply, and ways to get around them, while initiating the reader into how VoIP works with intuitive diagrams and information about different conversion processes from voice into digital packets and each ones’ advantages and disadvantages. It has chapters on advanced features and services unavailable to regular telephone systems, such as encryption and unified messaging, making great distance calls without the international charges and sharing pictures, graphs and files while attending a virtual seminar.

The next chapters explain such topics as Quality of Service, security and designing for and maintaining reliability. The book offers a good deal of information on how to secure connections both at the physical level, by preventing unauthorized access to the systems as well as data encryption. Finally, it offers insight into telephone number portability and setting up many global telephone numbers that are not charged more than an internet connection would be.

While not really suited for the experts, Introduction to IP Telephony is a good starting point for those who want to get into IP telephony or simply have an interest in VoIP technology and its applications.