What this book covers

Chapter 1, Introduction to SIP, introduces you to the SIP server. You will see how to recognize a SIP request and reply according to RFC 3261, identify the mandatory SIP headers, and describe the SIP routing process for initial and sequential requests.

Chapter 2, Introducing OpenSIPS, shows you how OpenSIPS is used in the market, the basic architecture of the system, use cases, and the main target market.

Chapter 3, Installing OpenSIPS, shows you how to download the OpenSIPS source and its dependencies, compile and install OpenSIPS with MySQL and Radius support, and configure the Linux system to start OpenSIPS at boot time.

Chapter 4, OpenSIPS Language and Routing Concepts, introduces you to the OpenSIPS scripting language and OpenSIPS routing concepts. After reading this chapter, you should be able to recognize the OpenSIPS script language, describe its mains commands, process initial requests, and drop or route requests.

Chapter 5, Subscriber Management, shows you how to manage subscribers in the system using the subscriber, location, group, and address databases. You will learn how to implement a multidomain system that is able to support multitenant implementations.

Chapter 6, OpenSIPS Control Panel, demonstrates how to install a web GUI to help with the provisioning of users, dialplan, routes, and other information that is required to run OpenSIPS. You will see how to install, use, configure, and customize the OpenSIPS control panel.

Chapter 7, Dialplan and Routing, enables you to integrate OpenSIPS with PSTN through gateways, selecting the best gateway, and failing over automatically if a response code is negative.

Chapter 8, Managing Dialogs, shows you how to activate the dialog module, limit the number of simultaneous calls, disconnect hanged calls, impose a maximum duration time for a call, and implement SIP session timers integrated with the dialog module.

Chapter 9, Accounting, demonstrates how account calls generate a CDR (Call Detail Record), account correctly forwarded calls, prevent calls without BYE, and add extra fields to the CDR.

Chapter 10, SIP NAT Traversal, helps you implement an OpenSIPS solution for clients behind NAT. You will see how to implement OpenSIPS in a data center such as Amazon AWS where all the servers are behind NAT.

Chapter 11, Implementing SIP Services, implements services such as call forward, forward on busy, and forward on no answer in cooperation with a media server and SIP phone.

Chapter 12, Monitoring Tools, enables you to detect performance issues using the built-in statistics. These include protocol issues using SIP trace, database issues using the benchmark module, script issues using the script trace, and software and hardware issues using GDB.

Chapter 13, OpenSIPS Security, shows you how to increase the security of your OpenSIPS installation.

Chapter 14, Advanced Topics with OpenSIPS 2.1, covers some advanced topics that can be important for specific installations. Topics such as asynchronous processing, TCP and TLS support, binary replication, and NoSQL integration for clusters are discussed.