Voice over IP Fundamentals

Chapter 1. Overview of the PSTN and Comparisons to Voice over IP The Public Switched Telephone Network (PSTN) has been evolving ever since Alexander Graham Bell made the first voice transmission over wire in 1876. But,...

Chapter 2. Enterprise Telephony Today Enterprise Telephony (ET) is a business telephone system that provides basic business features, such as call hold, three-way calling, call transfer, and call forwarding. ET shares m...

Chapter 3. Basic Telephony Signaling Many corporations find it advantageous to operate their own voice networks, and they do so by connecting dedicated links between Private Branch eXchanges (PBXs) for inter-office comm...

Chapter 4. Signaling System 7 Signaling System 7 (SS7) is a common-channel signaling standard developed in the late 1970s by the International Telecommunication Union Telecommunication Standardization Sector (ITU-T), fo...

Chapter 5. PSTN Services Today's Public Switched Telephone Network (PSTN) offers many different services, each with a desirable suite of features and functionality. Service providers (SPs) can offer competitive services...

Chapter 6. IP Tutorial Many of the benefits of voice over IP (VoIP) are derived from the use of Internet Protocol (IP) as the transport mechanism. To truly understand these benefits, you must first understand what IP ac...

Chapter 7. VoIP: An In-Depth Analysis To create a proper network design, it is important to know all the caveats and inner workings of networking technology. This chapter explains many of the issues facing Voice over IP...

Chapter 8. Quality of Service Quality of service (QoS) is an often-used and misused term that has a variety of meanings. In this book, QoS refers to both Integrated Services (IntServ) and Differentiated Services (DiffSe...

Chapter 9. Billing and Mediation Services Billing and mediation services are important in voice over IP (VoIP). They are key factors in helping a service provider or an enterprise vendor understand financial aspects, su...

Chapter 10. Voice Security This chapter provides an overview of typical security requirements in the context of Voice over IP (VoIP) service. You will learn about the various techniques to deploy to meet those requireme...

Chapter 11. H.323 H.323 is an International Telecommunication Union Telecommunication Standardization Sector (ITU-T) specification for transmitting audio, video, and data across an Internet Protocol (IP) network, includ...

Chapter 12. SIP Session Initiation Protocol (SIP) is a signaling protocol that controls the initiation, modification, and termination of interactive multimedia sessions. The multimedia sessions could be as diverse as au...

Chapter 13. Gateway Control Protocols This chapter covers two Internet Engineering Task Force (IETF) gateway control protocols that control Voice over IP (VoIP) gateways from external call-control elements: Media Gatewa...

Chapter 14. PSTN and VoIP Interworking The previous chapters described public switched telephone network (PSTN) and various Voice over IP (VoIP) technologies in isolation from one another. In real-world carrier networks...

Chapter 15. Service Provider VoIP Applications and Services Chapter 14 showed how enterprise businesses are trying to more effectively manage their communications using Voice over IP (VoIP) in their business. The enterp...

Chapter 16. Enterprise Voice over IP Applications and Services As enterprise businesses enter the 21st century, they are faced with constant demands to create more goods and services, improve the quality of their custom...