PBXs

An acronym for Private Branch eXchange. PBX telephone systems support incoming calls from the outside PSTN, placing calls between users' phones (also known as extensions) and other phones or the outside PSTN, conferencing other users together, recording voicemails and a variety of other advanced telecommunication functions.

PBX systems are broadly broken into several categories:

• Traditional (also known as legacy) - Usually don't support IP at all or support it only with expensive add-on equipment
• Converged (also known as hybrid) - Support IP and PSTN connections with equal force. Most flexible and cost-effective model
• IP-PBX - Support only IP connectivity. Any PSTN connectivity must be achieved through external converters (Gateways)

Learn More: Back to Basics - What is a PBX?

Type: Software-based IP PBX
Platform: Open Standards
Overview: 3CX is a software-based, open standards IP PBX that offers complete Unified Communications, out of the box. 3CX makes installation, management, and maintenance of your PBX so easy that you can effortlessly manage it yourself, whether on an appliance, on your servers or in your cloud account.

Type: Hosted Solution
Capacity: Up to 20-30 users
Overview: Preconfigured, ready-to-go shared instance. Recommended for most small businesses. StartUP is only available hosted by 3CX.

Sign up for your free 3CX business comms system: here

Type: Open Source PBX
Platform: Linux/UNIX
Created: 1999
Overview: Asterisk is a telephone private branch exchange (PBX), created as open software for Linux and other UNIX-like systems. Like other private branch exchanges, it allows attached telephones to make calls to one another and provides connections to outside lines.

Connection Methods to VoIP.ms:

• Asterisk (IAX2) - Inter-Asterisk protocol
• Asterisk (SIP) - Standard Session Initiation Protocol
• Asterisk (PJSIP) - Open Source Embedded SIP protocol stack

Resources:

• Free HTML documentation
• Official Asterisk website

Type: Enterprise PBX
Target: Small and Medium Enterprises
Overview: Avaya is a leading global provider of next-generation business collaboration and communications solutions, providing unified communications, real-time video collaboration, contact center, networking and related services to companies of all sizes around the world.

Type: Router/Switch Operating System
Platform: Cisco Hardware
Overview: Cisco IOS (originally Internetwork Operating System) is software used on most Cisco Systems routers and current Cisco network switches. IOS is a package of routing, switching, internetworking and telecommunications functions integrated into a multitasking operating system.

Type: Unified Business Communications
Target: Global client base
Overview: E-MetroTel provides unified business communications systems through leading-edge telephony hardware and software. Delivers streamlined migration to complete solutions that tightly integrate digital, IP, analog, and Unified Communications capabilities.

Type: Open Source Unified Communications
Platform: CentOS/Asterisk-based
Overview: Elastix is an open source unified communications server software that brings together: IP PBX, Email, IM and Faxing. The Elastix functionality is based on open source projects including Asterisk, HylaFAX, Openfire and Postfix.

Type: IP PBX Appliance
Experience: 18+ years
Overview: For over 18 years Epygi has been designing, manufacturing, and delivering IP PBX and IP Gateway appliances. They serve customers ranging from small businesses to enterprise companies, each benefiting from Epygi's excellent value and service.

Type: Open Source Web-based PBX
Platform: Asterisk-based
Overview: As an open source, web-based PBX solution, FreePBX is easy to customize and adapt to your changing needs. FreePBX is currently being used to manage the business communications of all sizes and types of businesses from small one person SOHO businesses, to multi-location corporations and call centers.

Type: Open Source Telephony Platform
Created: 2006
Overview: FreeSWITCH is a scalable open source cross-platform telephony platform designed to route and interconnect popular communication protocols using audio, video, text or any other form of media. Created to fill the void left by proprietary commercial solutions.

Type: Appliance-based IP PBX
Target: SMB and Enterprise
Overview: Grandstream Networks has been connecting the world since 2002 with SIP Unified Communications solutions. Award-winning solutions serve the small and medium business and enterprises markets, recognized for quality, reliability and innovation.

Type: Open Source Unified Communications
Platform: Multi-platform (CentOS, Rocky, Debian, Ubuntu, Raspbian)
Overview: GPL aggregation which bundles industry-leading components to provide a production-ready, turnkey unified communications VoIP platform with support for SIP and IAX. Includes Apache, PHP, MariaDB/MySQL, and latest releases of Asterisk and FreePBX.

Type: Legacy PBX System
Platform: Traditional/Hybrid
Overview: Avaya BCM450 (formerly Nortel BCM 450) and the BCM50 with VOIP or SIP Trunk keycode license. Popular legacy Nortel phone system that uses classic Nortel "Meridian" M and T series digital sets and Unistim IP phones.

Type: Hosted PBX Service
Platform: Cloud-based
Overview: PBXes is a hosted PBX running like a voicemail service or an email server in a data center. Like a classical PBX it serves as the bridge between your organisation (the extensions) and the public telephone network (the trunks). As trunks any SIP providers worldwide may be used.

Type: Hotel Communication Solutions
Industry: Hospitality
Overview: PhoneSuite is a leading provider of hotel voice communication solutions for over 25 years. Leverages expertise in communication technology to provide high-quality, low-power consuming products designed exclusively for the hotel industry.

Type: All-in-one Communications Platform
Features: Voice, Video, Messaging, SMS, WhatsApp, Meetings
Overview: PortSIP is an all-in-one communications platform designed to meet the needs of modern businesses. Offering a comprehensive suite of tools for voice, video, messaging, SMS, WhatsApp, video meetings, contact centers, and team collaboration.

Type: IP PBX Solutions
Target: Small and Medium Businesses
Overview: Positron IP PBX solutions offer small and medium sized businesses powerful VoIP phone systems that combine voice and data into one easy-to-use device, also known as Unified Communications. Features traditionally only available to large companies.

Type: IP PBX System
Company: ScopServ International Inc.
Overview: ScopServ International Inc. is a global pioneer in IP telephony solutions design (VoIP). The integrated system SCOPTEL IPBX provides one of the most stable environments and richest on the market.

Type: Multimedia Gateway
Location: China
Overview: Synway, as a world-leading VoIP enabling-technologies provider in China, has been specialized in providing superior Multimedia Gateway, Integrated Multimedia Switch, Telephony Hardware in use for Telecom communications.

Type: Small Business Phone System
Features: Easy Installation
Overview: Unlike other small business telephone systems, TalkSwitch is easy to install, saving you time and money; you can even do it yourself. With easily configured settings, moving employees or changing call handling is a snap.

Type: Cloud Phone Solution
Setup Time: Minutes
Overview: Only minutes to set up a reliable, full-featured phone solution. Part of Ubiquiti's comprehensive networking and communications ecosystem.

Type: Free Communications System
Platform: Linux/Asterisk-based
Overview: VitalPBX is a free telephone and communications system for companies. Complete platform that can be installed on physical hardware on-site or as a hosted application. Acts as the upper layer interface for the Linux base and Asterisk.

Type: Software-based IP PBX
Platform: Open Standards
Overview: Vodia PBX is a software-based, open standards IP PBX that offers complete UC functionality right out of the box. Makes installation, management, and maintenance so easy that you can effortlessly manage it yourself.

Type: Unified Communications Platform
Target: MSPs and UCaaS providers
Overview: Wazo is a unified communications technology provider that helps MSPs stand out from the crowd and build unique UCaaS experiences with simple, powerful, flexible APIs and integrations. Global reach with entities in Canada, United States, and France.

Type: Unified Communications
Focus: Communications-Enabled Business Processes
Overview: Communications-Enabled Business Processes: Wildix Unified Communications solutions enter the business processes to enhance the workplace efficiency and improve the productivity of your team.

Type: Omni Channel Contact Center
Platform: Asterisk-based
Overview: XCALLY is an innovative Omni Channel solution that integrates Asterisk with Shuttle and Motion technologies. One of the best Contact Center management platforms for multi-channel - voice, chat, email, SMS, fax, and custom channels.

Type: Business Telephony Solutions
Specialization: Integrated Solutions
Overview: Xorcom designs and manufactures integrated business telephony solutions that support both traditional PSTN and VoIP, including IP PBX, Hotel Phone Systems, Virtual PBX Systems, and Multi-tenant PBX.

Type: VoIP PBX Systems
Target: SMBs
Overview: Designed for SMBs, Yeastar S-Series/P-Series VoIP PBX and Yeastar Cloud PBX deliver enterprise-grade communications features along with advanced UC capabilities, bringing solid, reliable and affordable voice solutions.

• Trixbox - Project has not been maintained since 2010. You might want to look for alternatives.
• SIPfoundry - Open source project with limited ongoing development.

For new deployments, we recommend choosing from the modern PBX solutions listed above.