FreeSWITCH is a core switching and mixing matrix with dozens of modules around it, providing functionalities and features.

Lowest level control provided by events allows us to effectively leverage the toolbox approach, where we can choose how and when to use the single tools and techniques.

We have in our full control the entire wealth of real-time information that composes all communication packets flowing in and out of FreeSWITCH.

At the same time, we can bring each functionality from any module to life, invoking it at the right moment.

Full knowledge and full control allows us to tailor FreeSWITCH to the minimum details of our project, we'll never be forced to admit: "I can't do that".

In this chapter, we'll see:

• What is the Event System and its role in FreeSWITCH
• How Events look like
• How to connect to mod_event_socket
• Why Event Socket Library is so relevant
• How to write scripts to leverage the power of ESL