Introduction

The use of Voice over IP (VoIP) is rapidly expanding. You can find all sorts of glowing statistics about the adoption of VoIP by businesses and consumers. Traditional telecommunications companies are phasing in IP voice in parts of their backbone. Service providers are lowering the cost to businesses of implementing VoIP by offering hosted and managed solutions. Organizations both large and small are embracing VoIP.

Voice gateways are an essential part of VoIP networks. Gatekeepers and IP-to-IP gateways help these networks scale. Yet no definitive reference is available on these subjects. A network engineer who needs to design a VoIP network or configure these devices has to search to find the necessary information. This book strives to fill that need as much as humanly possible. It builds on the foundation laid by the Cisco CVoice course, focusing on advanced deployment options and features of Cisco IOS-based voice gateways and gatekeepers.

In a field that is constantly changing and developing, great care has been taken to make this book relevant and accurate. The authors hope that you will find it a good learning tool and a good resource for implementing and troubleshooting your voice gateways and gatekeepers.

Goals and Methods

The goal of this book is to produce a practical guide to help people both understand Cisco gateways and gatekeepers and configure them properly. This book seeks to describe the Cisco voice gateway and gatekeeper theories and protocols in a way that readers can apply to their networks. It provides examples, screen shots, configuration snips, and case studies to make this a useful guide and a reference book. The book includes the typical tasks and issues in deploying voice gateways and gatekeepers, in addition to advanced features and capabilities. Emphasis is placed on the accepted best practices and common issues encountered. It is not written specifically as a preparation for the Cisco Gateway Gatekeeper exam, but the topics that are covered on the exam are included in this book.

Who Should Read This Book?

Primary target audiences for this book are network engineers, IP Telephony engineers, and Telco engineers who are tasked with the installation, configuration, and maintenance of VoIP and IP Telephony networks. Secondary audiences include network managers and certification candidates who would like to augment their Cisco Gateway Gatekeeper exam preparatory material with more in-depth information. This book also serves as a resource to CCVP and CCIE voice candidates who are preparing for the written or lab exams.

It is assumed that the reader understands IP networking and is familiar with the topics covered in the following Cisco courses: CVoice, CIPT, QoS, and IPTT. This includes a basic understanding of VoIP and time-division multiplexing (TDM) voice fundamentals, the concepts and configuration of basic IP voice routers, and Cisco CallManager basics.