The advantages of Asterisk
Asterisk has become the de facto standard in modern VoIP PBX systems. It is a complete PBX in software, which means that it doesn’t require special hardware in order to work properly – you can even install it on your desktop PC. This software implementation of a PBX offers a number of benefits, some of which are described next.
Asterisk is free to install and use. Proprietary PBX solutions from companies such as Cisco or Avaya can cost thousands of dollars, even without offering some of the features included in Asterisk.
Asterisk source code is freely available for anyone to download and modify. You can add functionality to Asterisk with many different programming languages (Perl, PHP, C, bash…). This is in contrast to traditional proprietary PBX solutions where the source code is kept secret and any customization is almost impossible.
Number of features
Asterisk includes many features, some of which are not included even in the most expensive paid PBX solutions. Voicemail services with a directory, call conferencing, automated attendant and IVR, call queues, voice recording are just some of the features built into Asterisk.
One of the greatest strengths of Asterisk is the passionate community responsible for software development and support. There are numerous wikis, forums, mailing lists, IRQ channels… You can easily find information on fixes, how to’s, and get answers to your problems.