Asterisk Architecture

 The core modules in Asterisk provide essential features and services. Here are some of the key core modules:

Channel Drivers: Channel drivers are responsible for handling the communication between Asterisk and external devices or protocols. They provide support for various telephony interfaces such as analog (e.g., FXS, FXO), digital (e.g., T1, E1), and VoIP protocols (e.g., SIP, IAX2). Examples of channel drivers include chan_sip, chan_pjsip, and chan_dahdi.

PBX Core: The PBX (Private Branch Exchange) Core module forms the heart of Asterisk. It handles call routing, call control, and implements the PBX functionality. The PBX Core module is responsible for processing dial plans, call queues, call forwarding, call transfer, voicemail, and other call-related features.

Call Detail Records (CDR): The CDR module logs information about calls, such as call duration, source, destination, and other call metadata. It is useful for generating billing information, call analysis, and reporting.

Voicemail: The Voicemail module provides voicemail services, allowing users to receive and store voice messages. It supports features like message playback, message retrieval, message forwarding, and email notification.

Conferencing: Asterisk includes a conferencing module that enables multi-party audio conferencing. It supports various conference types, including ad-hoc conferences, scheduled conferences, and secure conferences.

Call Files: Call Files module allows users or applications to initiate outgoing calls programmatically. It provides a mechanism to schedule and control automated outbound calling scenarios.

Interactive Voice Response (IVR): The IVR module enables the creation of interactive voice menus and prompts. It allows callers to navigate through menu options, enter digits, and interact with the system using voice or keypad inputs.

Database Integration: Asterisk can integrate with various databases to retrieve or store information related to calls and users. Modules like res_config_mysql and res_config_odbc provide connectivity to MySQL and ODBC-compliant databases, respectively.

These are just a few examples of the core modules in Asterisk. Additionally, Asterisk offers a wide range of additional modules and features, which can be added or customized based on specific requirements, making it a highly versatile platform for building communication applications.