This book explains why and how companies are using IP Telephony equipment and software to efficiently upgrade existing telephone systems, develop their own advanced communications services, and to more easily integrate telephone network with company information systems. IP telephony technology has become a reliable communication option that has well-established standardized communication protocols. IP Telephony systems have many low cost devices and software application development tools available compared to proprietary telephone systems and services. The use of IP Telephony products and software allows companies to cost-effectively upgrade and eventually replace existing (legacy) telephone systems with more cost effective and easy to use telephone equipment. Because IP Telephony systems commonly use standardized protocols, this allows end-users and system administrators to have more control and to develop advanced communication services (such as smart voice mail) that have been traditionally been unchangeable and limited. IP Telephony commonly uses text-based protocols (similar to web HTML) and this allows for relatively easy development and integration with existing company information systems to produce new revenue producing services (such as integrating telephone and order processing systems). Not all IP Telephony systems and services are the same. There are cost and quality tradeoffs along with common problem areas and risks. There are many ways IP Telephony systems can reduce telecommunication costs along with the ability to create new revenue producing services. This book will help you to understand what IP Telephony is, how it operates, what services it can provide, and howyour company can benefit from installing and using IP Telephony systems.