Amazingly enough, Asterisk has more features than most traditional PBX systems, which are composed of a large box full of hardware. Hence, the Asterisk mantra of 'it's just software'. The following is only a partial list of the many features included with Asterisk:
Automated Attendant: An automated system for answering incoming calls and routing them based on the caller's responses to voice prompts.
Blacklists: Blacklisting is the ability to easily add numbers to a central database that will prevent calls from the blacklisted phone numbers being processed by the system.
Call Detail Records: The detailed call reports and usage statistics to show an administrator the activity of the phone system.
Call Forward on Busy: This feature automatically forwards a call to another extension if the called extension is busy.
Call Forward on No Answer: This feature automatically forwards a call to another extension if the called extension does not answer.
Call Parking: This feature refers...