Event system architecture

The event subsystem in FreeSWITCH was designed to maximize throughput and prioritize events depending on their type and the system load. There are two layers within the event system of FreeSWITCH. The first layer provides internal event handling routines and an interface for absorbing (or "consuming") events within FreeSWITCH itself. The second layer is provided by the modular architecture and provides the client-facing access to those events. By keeping these two units of functionality separate, the availability of a publish/subscribe style event system becomes apparent.

Within the internal event layer, FreeSWITCH provides core functionality that handles events occurring both on a system-level and a channel-level. Events can be published or broadcast by any part of the system, including modules. Two core types of events generally exist—system events and logging events. System events are generated by the core subsystem components or by modules. They include everything...