What is Asterisk

Asterisk is an open source framework for building communications applications. Asterisk turns an ordinary computer into a communications server. Asterisk powers IP PBX systems, VoIP gateways, conference servers and other custom solutions. It is used by small businesses, large businesses, call centers, carriers and government agencies, worldwide. 

Today, there are more than one million Asterisk-based communications systems in use, in more than 170 countries. Asterisk is used by almost the entire Fortune 1000 list of customers. Asterisk can become the basis for a complete business phone system, or used to enhance or extend an existing system, or to bridge a gap between systems.  

What Makes Asterisk Different

Asterisk is open source, which means you can get under the hood, see how it works and make any changes or enhancements you like. Asterisk is flexible and lets you define the solution that truly fits your requirements. Asterisk is stable, reliable and in production on thousands of systems worldwide.

It allows you to use a variety of IP telephones including:
  • Polycom
  • Cisco/Linksys
  • Grandstream
  • Digium
  • HTek
  • Mitel
  • Panasonic
  • Snom
  • Yealink
  • and more


Features

The Asterisk software includes enterprise features available in proprietary PBX systems including:

  • ADSI On-Screen Menu System
  • Alarm Receiver
  • Append Message
  • Authentication
  • Automated Attendant
  • Blacklists
  • Blind Transfer
  • Call Detail Records
  • Call Forward on Busy
  • Call Forward on No Answer
  • Call Forward Variable
  • Call Monitoring
  • Call Parking
  • Call Queuing
  • Call Recording
  • Call Retrieval
  • Call Routing (DID & ANI)
  • Call Snooping
  • Call Transfer
  • Call Waiting
  • Caller ID
  • Caller ID Blocking
  • Caller ID on Call Waiting
  • Calling Cards
  • Conference Bridging
  • Database Store / Retrieve
  • Database Integration
  • Dial by Name
  • Direct Inward System Access
  • Distinctive Ring
  • Distributed Universal Number Discovery (DUNDi™)
  • Do Not Disturb
  • E911
  • ENUM
  • Fax Services
  • Flexible Extension Logic
  • Interactive Directory Listing
  • Interactive Voice Response (IVR)
  • Local and Remote Call Agents
  • Macros
  • Music On Hold
  • Music On Transfer
    • Flexible Mp3-based System
    • Random or Linear Play
    • Volume Control
  • Predictive Dialer
  • Privacy
  • Open Settlement Protocol (OSP)
  • Overhead Paging
  • Protocol Conversion
  • Remote Call Pickup
  • Remote Office Support
  • Roaming Extensions
  • Route by Caller ID
  • SMS Messaging
  • Spell / Say
  • Streaming Media Access
  • Supervised Transfer
  • Talk Detection
  • Text-to-Speech (via Festival)
  • Three-way Calling
  • Time and Date
  • Transcoding
  • Trunking
  • VoIP Gateways
  • Voicemail
    • Visual Indicator for Message Waiting
    • Stutter Dialtone for Message Waiting
    • Voicemail to email
    • Voicemail Groups
    • Web Voicemail Interface