Building Telephony Systems with Asterisk

Asterisk is a powerful and flexible open source framework for building feature-rich telephony systems. As a Private Branch Exchange (PBX) which connects one or more telephones, and usually connects to one or more telephone lines, Asterisk offers very advanced features, including station-to-station calls, line trunking, call distribution, call detail rerecords, and call recording.

Asterisk can be used to provide Interactive Voice Response (IVR). The power and flexibility of a programmable phone system gives us the ability to respond to our customers in meaningful ways.

Asterisk has also a fully-functional voicemail system included. It supports voicemail contexts so that multiple organizations can be hosted from the same server.  It supports different time zones so that users can track when their phone calls come in.  It even provides the option to notify the recipient of new messages via email.  In fact, we can even attach the message in audio!

Finally, Asterisk is a Voice Over IP (VoIP) system. The benefits of VoIP are numerous. For instance, we can have multiple users using the same Asterisk service from a variety of locations; we can have users in the local office using PSTN phones or IP phones; we can have remote VoIP users; we can even have entire Asterisk systems operated and run completely separately but with integrated routing; We can have an extension anywhere we have a reasonably fast Internet connection, which means employees can have an extension on the phone system at home if they have a broadband connection. The benefits are too many to list.

Flexibility often means complexity, and this is true in the case of Asterisk. This book is all you need to understand and use Asterisk to build the telephony system that meets your need. You will learn how to use the many features that Asterisk provides you with.

Asterisk是一個功能強大且靈活的開源框架，用於構建功能豐富的電話系統。作為一個私有分支交換（PBX），它可以連接一個或多個電話，通常還可以連接一個或多個電話線。Asterisk提供非常先進的功能，包括站對站呼叫、線路集中、呼叫分配、呼叫詳細記錄和呼叫錄音。

Asterisk可以用於提供互動語音響應（IVR）。可編程電話系統的強大和靈活性使我們能夠以有意義的方式回應客戶。

Asterisk還包含一個完全功能的語音郵件系統。它支持語音郵件上下文，因此可以從同一個服務器上托管多個組織。它支持不同的時區，以便用戶可以追踪他們的電話呼叫時間。它甚至提供通過電子郵件通知收件人有新消息的選項。事實上，我們甚至可以附加音頻消息！

最後，Asterisk是一個IP語音（VoIP）系統。VoIP的好處很多。例如，我們可以讓多個用戶從不同的地點使用同一個Asterisk服務；我們可以讓辦公室內的用戶使用PSTN電話或IP電話；我們可以有遠程VoIP用戶；我們甚至可以完全獨立運行整個Asterisk系統，但具有集成路由功能；只要有合理快速的互聯網連接，我們就可以在任何地方設置分機，這意味著員工在家中如果有寬帶連接，就可以使用電話系統的分機。好處太多了，無法一一列舉。

靈活性通常意味著複雜性，在Asterisk的情況下也是如此。這本書是您理解和使用Asterisk構建滿足您需求的電話系統所需的全部。您將學習如何使用Asterisk提供的許多功能。