Gateways and Gatekeepers

This book will help you understand the roles of IP voice gateways and gatekeepers and how to integrate them into your voice network.

Gateways can be configured with many different features and functions and can become quite complex. It is important for network engineers to understand gateway functions, be able to choose when to use which, and be able to configure their gateways. Engineers need a thorough understanding of gatekeeper function and configuration to ensure proper call flow. In addition, they must address issues of security and redundancy.

This chapter provides an overview of the basic building blocks of a Voice over IP (VoIP) network. It includes information on the following:

• Voice gateways, H.323 gatekeepers, and IP-to-IP gateways
• IP voice signaling and media protocols
• Call control devices

It also includes an overview of the network used in case studies throughout the book.