What this book covers

As a result of reading this book, you can expect to build on existing knowledge and gain new skills. Each chapter covers a particular topic, but throughout there is a focus on building an Asterisk system that can form the cornerstone of a serious commercial product, capable of matching or even exceeding the performance of well-known licensed products.

Chapter 1 talks about dialplan techniques including modular implementations by using macros, contexts, and so on to both refine the dialplan and improve the security of the system. It also discusses the use of the devstate() function.

Chapter 2 discusses customer network requirements and offers some good advice about potential issues within the customer network and how to resolve them, including the use of VLANs and Quality of Service.

Chapter 3 looks at routing in general, including Least Cost Routing (local, national, and international GSM gateways), fall-back routing, alternate routing, and so on. ENUM and DUNDi are also explained within this context.

Chapter 4 considers call center requirements, including queues, agents, call distribution strategies, performance monitoring and call recording issues. An Asterisk-based call center solution, VICIDIAL, is also discussed in some detail.

Chapter 5 introduces speech technology in the form of ASR, TTS, and SVI; followed by implementation advice and examples. Both Lumenvox and Cepstral packages are explored in detail.

Chapter 6 looks at methods that can be used to implement call accounting and billing solutions for Asterisk. In particular, Asterisk-stat and A2Billing are explored.

Chapter 7 discusses resilience and stability, giving you a guide to implementing highly-available Asterisk solutions for mission-critical applications. Use of failover and load-balancing techniques are explored.

Chapter 8 explores the comprehensive localization options within Asterisk, and also suggests some easily deployed security measures.

Chapter 9 considers interfaces with traditional analogue and digital telephony, giving more in-depth explanations of Libpri and DAHDI (formerly Zaptel), and discussing implementation considerations.

Chapter 10 tackles the good and bad points of using wireless technologies with Asterisk, covering Wi-Fi, dual-mode and DECT handsets. Some suggestions on routing via cell/mobile networks are also offered.

Chapter 11 looks at the good and bad points of Asterisk Graphical User Interfaces (GUIs), focusing on one of the most popular incarnations, FreePBX.

In Appendix A we also explore some of the softer skills required when selling Asterisk-based solutions, suggesting some sales strategies that can help you in a commercial environment.

In Appendix B you will find information you might want to include in sample emails when pitching.

In Appendix C you will find a sample appointment sheet which can be used as a template.