Asterisk is a complete PBX in software. It runs on Linux, BSD, Windows (emulated) and OS X and provides all of the features you would expect from a PBX and more. Asterisk does voice over IP in four protocols, and can interoperate with almost all standards-based telephony equipment using relatively inexpensive hardware.

Asterisk provides Voicemail services with Directory, Call Conferencing, Interactive Voice Response, Call Queuing. It has support for three-way calling, caller ID services, ADSI, IAX, SIP, H.323 (as both client and gateway), MGCP (call manager only) and SCCP/Skinny. Check the Features section for a more complete list.

Asterisk needs no additional hardware for Voice-over-IP, although it does expect a non-standard driver that implements dummy hardware as a non-portable timing mechanism (for certain applications such as conferencing). A single (or multiple) VOIP provider(s) can be used for outgoing and/or incoming calls (outgoing and incoming calls can be handled through entirely different VOIP and/or telco providers)

For interconnection with digital and analog telephony equipment, Asterisk supports a number of hardware devices, most notably all of the hardware manufactured by Asterisk's sponsor, Digium. Digium has single and quad span T1 and E1 interfaces for interconnection to PRI lines and channel banks . In addition, single to quad port analog FXO and FXS cards are available and are popular for small installations. Other vendors' cards can be used for BRI (ISDN2) or quad- and octo- port BRI based upon CAPI compatible cards or HFC chipset cards.

For interconnection with the cellular network (GSM or CDMA), Asterisk can use the Celliax channel driver or chan_mobile that is in the trunk now and there is also a unofficial backported version.

Lastly, standalone devices are available to do a wide range of tasks including providing fxo and fxs ports that simply plug into the LAN and register to Asterisk as an available device.

If you are looking for a software-based IP-PBX for Windows, 3CX offers a highly-regarded product.

The current release versions of Asterisk are 1.2.37, 1.4.36, 1.6.0.28, 1.6.1.20. 1.6.2.13, and Asterisk 1.8.0. The current beta is Asterisk 1.8 beta 5.

This Wiki covers both the stable and the development branch of Asterisk. When adding new commands, applications and options, please also add a note on *when* this was added so that users may compare with their version date.

Daily Asterisk News

• Asterisk 12 Progress Report – 12.2.0 and 12.3.0 (9 Jun 2014 | 7:57 pm UTC)
• Upgrade OpenSSL and A2Billing now (16 Apr 2014 | 5:19 pm UTC)
• JIRA, Commit Messages, and Smart Commits (oh my) (10 Apr 2014 | 5:12 pm UTC)
• Call center satisfaction survey - results are out (8 Apr 2014 | 4:27 pm UTC)
• Changes to Review Board Access (6 Mar 2014 | 3:47 pm UTC)
• New Asterisk Developer - George Joseph (6 Mar 2014 | 3:42 pm UTC)
• Asterisk 12.1.0 Now Available (4 Mar 2014 | 3:40 pm UTC)
• Asterisk 11.8.0 Now Available (4 Mar 2014 | 3:33 pm UTC)
• Asterisk 1.8.26.0 Now Available (4 Mar 2014 | 3:24 pm UTC)
• DAHDI-Linux and DAHDI-Tools 2.9.0 Now Available (24 Feb 2014 | 5:15 pm UTC)

VoIP Today News

Other Asterisk News

• 2014-09-04 - OpenSIPS Summit Las Vegas 2014 registration is officially open! Come experience a rich collection of workshops about OpenSIPS and Asterisk integration
• 2014-03-25 - Sequoia Mobile announces "alpha" version of Asterisk connector for Nuance ASR Recognizer
• 2014-03-13 - Agile CRM announces VoIP telephony integration. Source: PRWeb
• 2013-10-18 - Asterlook releases the Asterlook software that manages calls in Outlook with Asterisk IPBX; Press Release
• 2013-04-30 - Netfors releases chan_ss7 2.2.0 for Asterisk 11.x.
• 2013-03-28 - Asterisk 11.3 Asterisk 11.3 is the new current release.
• 2013-03-15 - DMLink releases their 24 port PCI-E asterisk analog card , runs DAHDI standard driver.
• 2013-03-15 - DMLink releases their single port PCI-E PRI asterisk card , runs DAHDI standard driver.
• 2013-03-05 - Exelysis Contact Center - The new version of Exelysis Contact Center for Asterisk is now released.
• 2012-10-20 - Asterisk compatible VXML server IEC - SIP/2.0+VXML 2.1 IVR Platform SRGS MRCP Server, Cloud/MRCP ASR/TTS , Linux/Windows Free One Channel.
• 2012-10-12 - Intuitive Voice Technology launches new reseller offering get three FREE PBX licenses for signing up.
• 2012:09:11 - Version 3.2 firmware for Zycoo ZX50 Series IP-PBX released Change log
• 2012-08-30 - DMLink releases their 4 port PCI-E asterisk card , runs DAHDI standard driver.
• 2012-04-12 - WeQ4U releases iPhone app that interfaces with their asterisk based call center queueing system.
• 2012-04-11 - DMLink releases their 8 port GSM asterisk PCI card GSM800P, runs DAHDI standard driver.
• 2012-04-11 - DMLink releases their new 24 port analog asterisk PCI card, runs DAHDI standard driver.
• 2012-03-28 - DMLink releases their online shop 2.
• 2012-03-28 - DMLink releases their online shop 1.
• 2012-03-08 - DMLink releases their 16 port PCI-E analog asterisk PCI card, runs DAHDI standard driver.
• 2012-03-07 - OpenVox Delivers The Cost Effective Tapping Application
• 2012-02-24 - OpenVox Releases Chan-Extra 2.0.1 To Add More Functions To GSM Applications
• 2012-02-14 - OpenVox Released Multiform Transcoding Solutions
• 2012-01-16 - DMLink releases their new 4 port analog asterisk PCI card, it runs DAHDI standard driver.
• 2012-01-10 - WeQ4U releases asterisk based call center queueing system. WeQ4U.
• 2011-12-27 - OpenVox Launches A Complete Asterisk-Based Appliance
• 2011-12-14 - Humbug And OpenVox Partner To Prevent Telecom Fraud
• 2011-12-09 - OpenVox Distributes New Octasic® SoftEcho Supporting DAHDI Driver
• 2011-11-29 - DMLink releases their new 16 port analog asterisk PCI card, support DAHDI standard driver, no patch needed.
• 2011-11-18 - OpenVox Announces FREE 24*7 Technical Support Program For Open Source Community
• 2011-11-15 - OpenVox Announces BRI Products Price Reduction with A Lifetime Warranty Upgrade
• 2011-08-26 - OpenVox New Embedded Asterisk Motherboard Released
• 2011-08-01 - PowerAST The World first open hardware/software designed embedded PowerPC dual core 1.2G CPU IPPBX platform (Up to 16 E1/T1/J1 with hardware EC modules supported) has been released first version.
• 2011-07-29 - Intuittech-Blog Over 600 people strong, in 7 countries. The worlds largest Asterisk organization takes shape!
• 2011-07-20 - VadaXchange Buddy version 1.0 released - new user-friendly call control interface developed on top of an Asterisk PABX. About time business PABX become user friendly!
• 2011-06-27 - Atcom PRI Cards New range launched - AX-1D, AX-2D and AX-4D. Optional Hardware Echo Cancellation module available.
• 2011-05-16 - Orderly Stats version 1.8 of OrderlyStats for Asterisk Call Centers has been released
• 2011-05-11 - Positron G1000 Asterisk Appliance Released - 150 concurrent calls
• 2011-05-10 - Positron Telecom 1U Rackmount PBX is now available
• 2011-04-22 - The Alvis-4-Ext: T1/E1 External PRI Channel Bank based on RtpBridge solution is announced by Odin TeleSystems!
• 2011-04-19 - DMLink releases their new 4 port GSM asterisk PCI card.
• 2011-04-09 - Free Asterisk Technology Day in Kuala Lumpur, 28 April 2011
• 2011-03-30 - How to add a Flash softphone to your webpage, if you use Asterisk PBX
• 2011-03-17 - Microbase CTI Microbase announced the release of Microbase CTI v2.0 - The pure Asterisk Based CTI Solution.
• 2011-03-02 - OpenVox Releases Hardware Echo Canceller for ISDN BRI Cards with LIFETIME warranty.
• 2011-02-24 - Evolution PBX 4.0 released (100's of new features) by Intuitive Voice Technology
• 2011-02-24 - DMLink releases their new 16 port analog asterisk PCI card.
• 2011-02-15 - Netfors has released version 2.0.0 of the SS7 channel driver for Asterisk, chan_ss7: Download here.
• 2011-02-02 - Intuittech Sdn Bhd launches Nagmon for Asterisk the monitoring appliance in conjunction with the DIGIUM ASTERISK WORLD 2011; Press Release
• 2011-02-02 - Membantu24 the first global Asterisk support centre is launched in conjunction with the DIGIUM ASTERISK WORLD 2011; Press Release
• 2011-02-02 - Hayibo! the softphone for the Enterprise releases the free version of its softphone in conjunction with the ITEXPO EAST 2011 in Miami; Press Release
• 2011-01-07 - Asterisk Nortel Asterisk Avaya Communications Manager with SES ,Avaya IP Office R6.0 ,BroadSoft BroadWorks

Starting Out

Books

• Addison-Wesley
  • The Asterisk Book - Practical Asterisk 1.4 - GNU FDL, completely available online
  • Das Asterisk Buch (German) - Asterisk 1.2 + 1.4 - GNU FDL, completely available online
• Booksurge
  • Getting Started With Asterisk PBX (English) Free downloadable eBook - Released in June 2010
  • Learning Guide for Asterisk 1.6 (English) Asterisk 1.4 and 1.6 - Released in June 2010
  • New Configuration Guide for Asterisk PBX 2011 in Portuguese Available New
• O'Reilly Media
  • Asterisk: The Future of Telephony - Brought To You By The Asterisk Documentation Project - FREE DOWNLOAD!
  • Switching to VoIP - Ted's book is full of Asterisk know-how
  • T1: A Survival Guide - Not specifically about Asterisk, but if you want to understand T1s, this is the book
• Packt Publishing
  • Asterisk Gateway Interface 1.4 and 1.6 Programming New
  • AsteriskNOW!

• Asterisk 1.4 Professional Guide with the Sample Chapter - FREE DOWNLOAD!
• Beginning OpenVPN 2.0.9 with the Sample Chapter - Features of OpenVPN - FREE DOWNLOAD!
• Building Enterprise Ready Telephony Systems with sipXecs 4.0 with the Sample Chapter
• Build rich telephony systems with Asterisk 1.6 with the Sample chapter - Creating a Dialplan - FREE DOWNLOAD!
• Construindo Sistemas de Telefonia com o Asterisk Asterisk book in Portugues released.
• Construyendo Sistemas telefónicos con Asterisk Asterisk book in Spanish released.
• Costruire Sistemi Telefonici con Asterisk Asterisk book in Italian released.
• Free Chapter from the Asterisk Book Building Telephony Systems With Asterisk
• Free Chapter from the Trixbox book trixbox CE 2.6 New
• FreePBX 2.5 Powerful Telephony Solutions with the Sample Chapter - Recording calls in FreePBX - FREE DOWNLOAD!
• Latest Asterisk Book Building Telephone Systems With Asterisk
• Latest Asterisk eBook Building Telephone Systems With Asterisk
• Sample Chapter FREE DOWNLOAD!
• TrixBox Made Easy book has just been Announced.
• Tutorial for Novice to get started with Asterisk - Day to day Plan

Introduction

• Asterisk introduction: An overview for new Asterisk administrators - THE PLACE TO START!!
• An introduction to Asterisk, The Open Source Telephony Project - Basic setup How-To/tutorial, installation, SIP-devices and dialplan, with test applications.
• Asterisk: A Non-Technical Review (pdf): An overview for executives and managers
• Asteriskguru Tutorials A huge collection of tutorials for asterisk.
• Asterisk installation
• Asterisk IRC logs: #asterisk IRC logs
• Asterisk Mailing Lists
• Asterisk software addons
• Asterisk tips and tricks: Solutions to common problems, hints of what you can do with this powerful software
• Asterisk video training Asterisk and Linux step by step installation guide
• Asterisk video training Free videos on Asterisk, trixbox, and FreePBX
• Asterisk video training Free videos on Asterisk, trixbox, and FreePBX
• Series of video tutorials about Asterisk dial plan development
• Blindhog.net - Video Tutorials.
• Collection of tutorials for Asterisk dial plan development
• Development Which development environment is best for my voice app? (Asterisk, usually!)
• FAQ and SEARCH helper: Look for answer for the question that bugs you here!
• Free Introduction to Asterisk eBook complete setup tutorial
• Free video tutorials about Asterisk dial plan
• http://www.suvi.org/theory/asterisk.html Gives a good German introduction howto setup Asterisk quickly.
• Linux 101: A beginners guide to using Linux
• Linux 101: A small wiki with snippets of useful Linux info
• News, Project status and roadmap
• Systm 5 - Asterisk: Video @ YouTube
• VoIP User Groups: Local resources in your area
• Where to download Asterisk

Hardware

• Asterisk Appliances
• Asterisk Hardware and Support Service An industry leader serving the Asterisk community since 05'
• VoIP Solutions and Network Accesories for Asterisk, trixbox and Windows based VoIP systems (recommendation of VoIP integration partner)
• Asterisk and Cable Modems with embedded ATAs: How to connect a embedded ATA to Asterisk
• Asterisk and Virtual Private Servers: How to run Asterisk on a VPS/VDS}
• Asterisk and VoIP Gateways: A list of many manufacturers of VoIP gateways
• Asterisk Blades: Standalone Asterisk based PCI cards
• Asterisk dimensioning: How big a processor do I need and what call load can my system handle?
• Asterisk Embedded Systems: Asterisk on no-frills hardware
• Asterisk Hardware blog Asterisk and Linux step by step installation and hardware recommendations guide
• Asterisk Hardware: Hardware known to work with Asterisk]
• asterisk hardwares hardware for Asterisk VoIP systems
• Asterisk Hardware and Support Service .e4 serving the Asterisk community since 05'
• VoIP Phones for Asterisk Systems
• Asterisk legacy integration: How to integrate Asterisk and an ordinary PBX
• Asterisk phones: Common phones in use together with Asterisk
• Asterisk text: Text communications support in Asterisk
• Asterisk video: Video call support in Asterisk
• Cheapest Asterisk hardware- DMLINk products hardware for Asterisk VoIP systems
• Cheapest Astesrisk cards india with 5 years of warrenty
• Cheapest IP PBX system and TDM cards hardware for Asterisk VoIP systems
• Hardware use cases: Hardware recommendations for different needs & success stories
• VoIP systems hardware for Asterisk VoIP systems
• Asterisk hardware - Atcom products for VoIP solutions
• Atcom asterisk appliances,Positron asterisk embedded blades,Positron asterisk appliances

Administration and system layout

• Asterisk administration
• Asterisk at large: Tips for large installations (SIP proxy, load balancing)
• Asterisk billing support
• Asterisk Bootable CDROM: Boot and run Asterisk from a CDROM
• Asterisk configuration from database
• Asterisk configuration from template files
• Asterisk dimensioning: What CPU do I need, how many concurrent calls does my hardware support?
• Asterisk encryption: About SRTP, TLS and IAX encryption
• Asterisk fax Asterisk and Faxing
• Asterisk groups: The various and confusing group concepts in Asterisk.
• Asterisk High Availability Solutions: Hardware and software solutions to increase availability.
• Asterisk Install CDROM: Simultaneously install an OS and Asterisk from one CDROM — easiest and quickest way to get Asterisk up and running.
• Asterisk monitoring: Making sure it stays up
• Asterisk OS Platforms: What Operating Systems Asterisk works with
• Asterisk password files: Where can you find users and passwords in Asterisk configuration files?
• Asterisk PBX functions: Introduction that helps you find common PBX functions in Asterisk
• Asterisk rollout tips: Tips on how to move from testing to practical rollout.
• Asterisk security: Security in the PBX
• Asterisk video training Asterisk and Linux step by step installation guide

Configuration

• Asterisk - documentation of application commands: The complete cross-reference!
• Asterisk AEL: Asterisk Extension Language
• Asterisk AEL2: Asterisk Extension Language - version 2
• Asterisk AGI: Powerful programmatic scripting interface
• Asterisk config files: Overview of the Asterisk configuration files
• Asterisk Configuration Examples: Complete Asterisk configuration examples from various users
• Asterisk Configuration from database
• Asterisk configuration from template files
• Asterisk Configuration Notes for Specific Phones
• Asterisk Configurations for connecting with VOIP providers: How to connect Asterisk to VOIP providers
• Asterisk Data Configuration: Zaptel and Asterisk data and hybrid configuration
• Asterisk Database: The built-in database used in the dialplan
• Asterisk Functions: The Functions used in 1.2
• Asterisk Slimming:How can we slim-up about so many modules
• Asterisk tips and tricks: Many config tips
• Asterisk Variables: Variables used in configuration and dial plan
• Asterisk video training Asterisk and Linux step by step installation guide
• Fax & Modem Support for Asterisk - white paper explaining how to synchronize devices
• Incoming Call Latency in Asterisk Systems with FXO - article describing how to reduce delay
• Treating Echo in Asterisk Systems - short article about the reasons and solutions to echo issues with Asterisk

Management

• Asterisk CLI: The interactive command prompt language
• Asterisk GUI: Web and other interfaces to Asterisk for management and configuration
• Asterisk Manager API: The Asterisk Manager API
• Asterisk options: Command line switches when you start your Asterisk PBX
• Asterisk Zeroconf Support: Service Discovery for Asterisk using Zeroconf
• DooxSwitch.com: Asterisk based advanced managment and communication solution. Routing, Billing, PBX, IVR menu, Callshop, Callcenter, DID shop , SMS, Calling Cards , Dialers , Softphones flexible API and many more.
• Asynchronous Javascript Asterisk Manager (AJAM) - HTTP Manager API Access

Troubleshooting

• Asterisk debugging: How to debug Asterisk
• Asterisk PCI bus Troubleshooting: Troubleshooting PCI bus issues (Especially those related to the Digium TDM400P)
• Asterisk PSTN interface debugging: Echo problem, signal level issues, etc.
• Asterisk Voice Delay: Options to reduce the delay between voice transmission and receipt

General Reference

• Asterisk codecs: Supported codecs
• Asterisk channels: Supported voice channels
• Asterisk International: How to make * work outside the USA
• Asterisk libpri: Open Source PRI library
• Asterisk multi-language: Tips on configurations for multi-language installations
• Asterisk Paging and Intercom
• Asterisk protocols: Supported protocols
• Asterisk sound files: Standard sound files and their meaning
• Asterisk vertical service activation codes: *XX codes used on Zap Channels

Country-Specific Information

• Asterisk VIETNAM Asterisk Solution in VIETNAM http://www.asteriskvietnam.com
• Asterisk Singapore Asterisk Solution in Singapore http://www.nautilus-network.com
• asterisk ActiveX The free Asterisk IAX2 and Manager API and AGI ActiveX control(know as IAXOCX and MVBCTI OCX).
• Australia Asterisk Details
• Emergency Calls
• http://bbs.voip88.com: Chinese Community provided Asterisk PBX and cards free support and Chinese version of Elastix
• http://mestreasterisk.com.br/: Blog/Portal Mestre Asterisk - News, Asterisk Videos, Tutorials, Installation and Configuration, you can find here! (Pt_BR).
• http://pbx-installers.com/dir/Asterisk/: Directory of Asterisk dealers and programmers in the United States
• http://www.51asterisk.com: Provide in depth and updated Asterisk China local news and also international information.
• http://www.asterisk.lv: Asterisk in Latvia
• http://www.asteriskdiy.com: An Asterisk WiKI in Thailand
• http://www.asteriskexpert.net: Asterisk Expert UK and USA , One call solution
• http://www.asteriskexperts.com.br: Portal, forum and tutorials about Asterisk in Brazil
• http://www.asteriskportugal.org: Portal, forum and tutorials about Asterisk in Portugal
• http://www.maug.com.my: Malaysian Asterisk User Group - Asterisk in Malaysia
• http://www.meuasterisk.com.br/: Blog/Guides Asterisk - Latest news and views about Asterisk/ Guias e ultimas noticias sobre asterisk (Portugues BR).
• http://www.voiptoday.org: VOIP Today Magazine - Keep up to date on the latest news and views about Asterisk.
• India Specific Information
• UK Asterisk Details
• The first Greek Asterisk Forum: Greek Asterisk Forum - Sounds Greek.

Commercial support

• Asterisk Support Service IT micro jobs is a market place to share Asterisk support service.
• Asterisk Hardware and Support Service An industry leader serving the Asterisk community since 05'
• Asterisk consultants: A list of Asterisk consultants
• Asterisk Help Wanted: Post Asterisk-related consulting projects
• Asterisk system vendors: Where to buy complete systems with Asterisk already installed
• Digium, the creators of Asterisk and Asterisk-compatible hardware
• Mantenimiento Asterisk para empresas Monitorización preventiva, backUp, atención y resolución de incidencias.
• Asterisk consultant for the New York Tri-State Area - Remote Asterisk support for USA

SIP Service Providers

• Sip Trunking Providers
• Asterisk settings for Localphone: How to configure Asterisk to work with Localphone’s VoIP service
• SIP/IAX Services for Asterisk: Where to obtain VoIP Services for Asterisk Platform
• Voip Call Shop Provides call shop sip acounts, used for call shops or residential customers.
• VoxCall
• DIDLive provides Asterisk SIP Inbound Service. Local DID Numbers in USA/Canada & 40 other countries. USA/Canada Toll Free Numbers.

Contact DIDLive at 1-212-901-0800 or visit us at www.didlive.com

User Groups

• Asterisk Army: Asterisk User Map - Forum
• Asterisk softswitch Asterisk is the worlds leading open source telephony engine and tool kit. Asterisk is released as open source under the GNU General Public License (GPL), and it is available for download free of charge.
• AsteriskCounter: Page that counts how many users uses Asterisk
• Asterisk Professionals: Certified Asterisk Professionals and Instructors
• Asterisk User Groups Hang out with Asteristas in your area!
• VOIP Today Community Providing the success and use of Asterisk also FREE Asterisk support.
• VoIP User Groups: Local resources in your area

Weekly SIP Asterisk Users Conference

• x2z.eu http://www.x2z.eu/ THis conference is open to users at all levels of asterisk expertise

Interesting and Unusual Projects

• Village Telco Using Asterisk in a WiFi Mesh network to provide phone service in rural areas

Howtos and Tutorials

• 28 Ways SANGOMA Makes Asterisk Better
• Asterisk 1.8 current VoIP Compile Script for CentOS 5 Rackspace Install Asterisk on Rackspace Cloud Server by jonathanmanning.com
• http://www.voiptuts.com/search/label/asterisk Asterisk sip Configuration and more
• How to add a Flash softphone to your webpage, if you use Asterisk PBX
• Series of video tutorials about Asterisk dial plan development
• An introduction to Asterisk, The Open Source Telephony Project - Basic setup How-To/tutorial, SIP-devices and dialplan, with test applications.

• AQuA enables voice quality monitoring in Asterisk
• Asterisk ""How To"" Search Tool Uses Google -No Ads - Just Asterisk information from all the best sites!
• Asterisk and Amazon EC2 cloud services - Voxilla
• Asterisk auto-dial out: How to make your PBX dial out automatically
• Asterisk Cisco 79XX XML Services: How-To Create XML scripts for Cisco 79XX Phones
• Asterisk Cisco CallManager Express Integration: How-To integrate Asterisk with Cisco CallManager Express
• Asterisk Cisco CallManager Integration: How-To integrate Asterisk with Cisco CallManager
• Asterisk Tutorials A wide variety of Asterisk Tutorials from AsteriskGuru.com
• Asterisk Tutorials - Free video tutorials for Asterisk, trixBox, and FreePBX
• Asterisk Voicemail Notify for Support Numbers: Asterisk Voicemail Notify for Support Numbers
• BLF Tutorial for Asterisk PBX and Linksys SPA962/932
• Collection of tutorials (easy to difficult) for asterisk
• Collection of tutorials for Asterisk dial plan development
• How to: Snom M3 and the Web UI (Simple)
• http://mestreasterisk.com.br - Howtos and Video Tutorial
• http://www.asterikast.com Asterikast.com Offering a free video tutorial for Asterisk.
• http://www.astrecipes.net A wiki about ready-to-run Asterisk recipes
• http://www.ctrcorp.com.mx Asterisk configuration
• Install and Configure Asterisk Server with Extensions in 3 Minutes - Video
• Integrating the Power of Open Source Telephony with Web 2.0 Technology
• Setting up a small scale solution for distributed sales force A practical example.
• Telemarketing blacklisting using Asterisk http://www.it-slav.net/blogs/2009/03/17/telemarketing-blacklisting-using-asterisk/
• Asterisk+Cisco CME integration
• Asterisk o Elastix Tutorial para decidir el mejor sistema para tu empresa.