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General Information
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February 2, 2007
• Vol.29 Issue 5
Page(s) 22 in print issue
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A Systematic Approach To VoIP
“Voice over IP Fundamentals, Second Edition” Covers The Basics
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Voice over IP Fundamentals, Second Edition
Authors: Jonathan Davidson, James Peters, Manoj Bhatia, Satish Kalidindi, Sudipto Mukherjee
Publisher: Cisco Press
Price: $55
Format: Paperback, 432 pages
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VoIP technology is enticing, promising lower operational costs, greater flexibility, and a variety of enhanced applications. If you are considering a move to VoIP in your enterprise or are looking to brush up on your VoIP knowledge, you might want to pick up “Voice over IP Fundamentals, Second Edition,” from Cisco Press.
 Understand The Basics
The authors tout the book as being suited for voice and data networking experts, although the slant seems to lean heavier toward anyone seeking to understand how to use IP to transport voice. The authors note that legacy TDM (time division multiplexing) PBXes are being quickly replaced by enterprise business communication tools. They say VoIP is not only a cheaper way to transmit voice but also a whole new way of communicating with peers and associates.
From a bird’s eye view, “Voice over IP Fundamentals” is intended to help readers understand the basics of enterprise and public telephony networking, IP networking, and how voice is carried over IP networks. The book also tells users where they need to be cautious when converging voice and data networks. The authors examine basic VoIP signaling protocols, as well as primary legacy voice signaling protocols including ISDN and C7/SS7 (Signaling System 7). They also discuss common VoIP topics such as jitter, latency, packet loss, codecs, QoS tools, and security.
Four Sections
“Voice over IP Fundamentals” is divided into four main parts. Part I deals with the evolution and basics of the PSTN (public switched telephone network). The PSTN is compared to VoIP, and ET (enterprise telephony) is covered, as well. Part I also provides an overview of basic telephony signaling and SS7, a common-channel signaling standard, along with a definition of some of the more common PSTN services.
Part II gets deeper into VoIP technology. The authors look at the basics of IP and various networking issues facing VoIP. They also cover billing and mediation services (key factors in helping an enterprise vendor understand the financial aspects surrounding VoIP) and voice security.
Part III defines the various IP signaling protocols. The H.323 standard, which lets vendor products and applications communicate and interoperate with each other, is described in detail. The book also covers popular signaling protocol SIP (Session Initiation Protocol), which controls the initiation, modification, and termination of interactive multimedia sessions. Part III ends by defining two Internet Engineering Task Force gateway control protocols that control VoIP gateways from external call-control elements: MGCP (media gateway control protocol) and H.248/MEGACO.
Part IV deals with voice applications and services. The section discusses alternatives for interworking between VoIP and PSTN, as well as service provider and enterprise VoIP applications and services.
Despite its discussions of voice and data networking, “Voice over IP Fundamentals” is mainly about VoIP. The book is a well-rounded reference guide for anyone designing, building, or deploying VoIP networks. As the book states, “VoIP, and in general, IP communications, is and will continue to be the de facto mechanism for communications for the foreseeable future.” Pick up a copy, even if you are only contemplating the move to VoIP. 
by Chris A. MacKinnon
Key Concepts
“Voice over IP Fundamentals” explains how a basic telephony infrastructure is built and operates. Key concepts include voice and data networking, the transmission of voice over data, and IP signaling protocols. This book also answers the following questions:
• What is IP?
• How is voice signaled in telephone networks today?
• What are the various IP signaling protocols, and which one is best for which types of networks?
• What is QoS, and how does one ensure good voice quality in a network?
The second edition of “Voice over IP Fundamentals” throws billing and mediation into the VoIP network mix, as well as security and common types of threats that lurk when packet voice environments, public PSTNs, and VoIP interoperate. Enterprise and service-provider applications and services are also explained. |
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