Asterisk

What Asterisk does

Asterisk is a free, open source framework for building real-time communications applications that converts commodity Linux servers into feature-rich voice and video communications platforms. Conceived in 1999 and originally developed by Digium, the project has been sponsored since the 2017-2018 acquisition of Digium by Sangoma Technologies and is released under the GNU General Public License v2. The framework abstracts a broad set of protocols and codecs — VoIP (SIP, H.323, IAX, Jingle/XMPP, MGCP, SCCP, UNIStim) plus legacy telephony (E&M, FXS, FXO, PRI, BRI, ISDN) and over a dozen audio codecs — and exposes three programmable APIs: the Asterisk Manager Interface (AMI) for monitoring and CTI, the Asterisk REST Interface (ARI) for HTTP/WebSocket-driven call control and Voice AI bridging, and the Asterisk Gateway Interface (AGI) for dialplan scripting. Built-in applications cover voicemail, automated attendant, call queuing, ConfBridge conferencing, paging, intercom, and IVR.

The commercial product portfolio extends the open source core with Sangoma-built components: FreePBX as the leading open source GUI, Certified Asterisk branches for SLA-backed enterprise deployments, PBXact Cloud as a hosted PBX service, Sangoma P-Series IP phones, VoIP gateways and telephony interface cards, and SIPStation / VoIP Innovations SIP trunking. Add-on modules include Fax for Asterisk, DPMA phone provisioning, HPEC echo cancellation, and binary commercial codec modules (G.729, Siren 7/14, SILK, Opus). Media Over WebSockets (October 2025) and the Taskpool API (November 2025) were added to support integration with external AI media bridges and to drive measurable performance improvements on SIP and telephony workloads.

Asterisk's business model is community-led with commercial monetization routed through Sangoma. The open source core is free under GPLv2; revenue is generated via five tiers of support subscriptions, commercial licensing for proprietary deployments, instructor-led training with SCAA/SCAP certification, SIP trunking subscriptions, and hardware sales — distributed through self-serve downloads, system integrators, the AsteriskExchange marketplace, and Sangoma's direct sales force. Deployment scale includes 11.5 million annual downloads, 85,000+ community members, 1,000,000+ communications systems in 170+ countries, and adoption across nearly the entire Fortune 1000.

Name

Asterisk

Legal name

Digium, Inc.

Website

https://asterisk.org

Company type

Private

Founded year

1999

Operating status

Operating

Headcount range

1–10 employees

Short description

Asterisk is an open source (GPLv2) framework, sponsored by Sangoma Technologies, that turns Linux servers into IP PBX, VoIP gateway, and conferencing platforms. It is used by developers, integrators, and nearly the entire Fortune 1000 across 170+ countries.

Ownership category

akta.pro rank

Product category

Open Source Communications Framework / VoIP Software

NAICS

Custom Computer Programming Services (541511), Computer Systems Design and Related Services (54151)

SIC

Services-Computer Programming, Data Processing, Etc. (7370)

akta.pro primary industry

Messaging APIs, CPaaS & Programmable Communications (BPAMACAL)

Keywords

• Open source communications
• VoIP PBX framework
• Telephony software platform
• IP PBX systems
• VoIP gateway solutions

Headquarters

HQ city

Washington

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B

Offering type

Software

Cost components

Technology or R&D, Personnel, Marketing or Sales, Infrastructure, Supply Chain, Operations

Revenue model

1. Commercial Licensing: Asterisk is distributed under dual license: GPLv2 (free open source) and commercial license for proprietary use cases. When users want to use Asterisk in ways, products, or markets not compatible with GPLv2, Sangoma offers commercial licensing of Asterisk. License fees vary depending on the application and scale of use.
2. Support Services: Sangoma provides five levels of support for Asterisk: Levels 1-4 cover Core modules of current major releases; Support Level 5 is for OEMs and enterprises requiring SLA and Engineering support with negotiated response and resolution times. Certified Asterisk is recommended for Level 5 support.
3. Professional Services: Sangoma offers implementation services, system integrators, and consulting for Asterisk deployments through certified partners.
4. Training and Certification: Sangoma offers instructor-led Asterisk training classes and two certification programs: SCAA (Sangoma Certified Asterisk Administrator) valid for 2 years, and SCAP (Sangoma Certified Asterisk Professional) covering specific stable versions.
5. SIP Trunking Services: Sangoma provides SIP trunking through SIPStation (for everyday users) and VoIP Innovations (for heavy users), available across the US and Canada.
6. Hardware Sales: Sangoma sells complementary hardware including P-Series IP phones (with plug-and-play deployment and advanced applications), telephony interface cards (analog, digital, media compression), and VoIP gateways.
7. FreePBX and PBXact Cloud: FreePBX is the #1 open source GUI for Asterisk (free). PBXact Cloud is Sangoma's commercial hosted PBX service providing Asterisk-based business phone system with advanced features on subscription basis.

Pricing tiers

Go-to-market motion3 records

Distribution channels10 records

Marketing channels10 records

Core offering

Asterisk is a free, open source (GPLv2) framework for building multi-protocol real-time communications applications. It turns an ordinary computer into a communications server that powers IP PBX systems, VoIP gateways, conference servers, IVR platforms, and custom solutions. Sponsored by Sangoma Technologies, it is paired with commercial products including FreePBX, PBXact Cloud, Sangoma IP phones, VoIP gateways, telephony interface cards, SIP trunking services (SIPStation), and tiered commercial support, training, and licensing offerings.

Product overview

Asterisk is an open source framework for building communications applications sponsored by Sangoma. The product portfolio consists of the core Asterisk Communications Framework (free, open source under GPLv2) which serves as the underlying engine for all communications functionality, combined with multiple complementary products and services. FreePBX provides an open source graphical user interface layered on Asterisk, while PBXact Cloud offers Sangoma's hosted commercial PBX. Sangoma provides a full hardware ecosystem including P-Series IP Phones, VoIP Gateways, and Telephony Interface Cards. SIPStation delivers SIP trunking services. Add-on modules extend Asterisk capabilities including Fax for Asterisk, DPMA for phone provisioning, HPEC for echo cancellation, and commercial voice codecs. Asterisk supports multiple APIs (AMI, ARI, AGI) for building custom applications. Certified Asterisk branches provide enterprise-grade stability with SLA support. Sangoma also offers commercial licensing for proprietary deployments, professional training with SCAA/SCAP certifications, and five-tiered support services. The AsteriskExchange marketplace hosts third-party products built on Asterisk. The annual AstriCon conference brings together the Asterisk community.

Differentiator

Problem solved

Functional benefit

Brands

• Certified Asterisk: A branch of Asterisk supported by Sangoma for commercial and SLA customers, provided under GPLv2 license.
• FreePBX
• SIPStation

Products and services

• Asterisk Communications Framework Free and open source (GPLv2) framework for building communications applications that converts an ordinary computer into a feature-rich voice communications server. Powers IP PBX systems, VoIP gateways, conference servers, IVR systems, call centers, and custom real-time communications solutions for developers, system integrators, and enterprises worldwide.
• FreePBX Open source graphical user interface (GUI) for Asterisk that makes it easier to build a custom phone system with a feature-rich core and many available modules/add-ons. Installable on Linux Debian systems.
• Certified Asterisk A commercially supported branch of Asterisk provided under GPLv2 license, undergoing additional testing and receiving limited bug fixes focused on stability and security for commercial and SLA customers.
• PBXact Cloud Sangoma's cloud-based IP PBX subscription service combining the Asterisk engine with an intuitive user interface and advanced business phone system features including instant messaging, SMS, queue, recordings, mobility, and softphones.
• Sangoma P-Series IP Phones Feature-rich IP phones designed to complement Asterisk with plug-and-play deployment, automatic server discovery, and advanced applications including Visual Voicemail, status indicators, and Contacts integration via DPMA.
• Sangoma VoIP Gateways Solid-state IP media gateways that convert phone calls between legacy circuit-switched technologies and modern packet-switched VoIP technologies, connecting legacy phone lines with Asterisk or legacy phone systems with VoIP services.
• Sangoma Telephony Interface Cards PCI/PCI Express expansion cards that connect computers running Asterisk to legacy phone lines, phones, and phone systems. Includes analog (FXS/FXO) and digital (T1/E1/ISDN) interface cards plus media compression/transcoding cards.
• SIPStation SIP Trunking Sangoma's SIP trunking service for Asterisk with channelized rate plans, unlimited inbound and outbound local and long-distance calls, local and Toll Free numbers, number porting, and redundancy across the US and Canada.
• Fax for Asterisk Commercial add-on for Asterisk providing dialplan functions and applications for building custom fax solutions with transmit and receive capabilities.
• Digium Phone Module for Asterisk (DPMA) Module that adds automated provisioning and application integration features for Sangoma D-Series IP phones to Asterisk installations, enabling secure no-touch provisioning.
• High Performance Echo Cancellation (HPEC) Carrier-grade software echo canceller add-on for use with Sangoma telephony cards that do not include hardware echo cancellation.
• Sangoma Voice Codecs (G.729, Siren 7, Siren 14, SILK, Opus) Commercial codec modules distributed by Sangoma for Asterisk in binary form, including G.729 (8 kbps compression), Siren 7, Siren 14, SILK (wideband), and Opus codecs.
• Asterisk Training Courses Instructor-led Asterisk training classes plus certification programs including SCAA (Sangoma Certified Asterisk Administrator, 2-year validity) and SCAP (Sangoma Certified Asterisk Professional).
• Asterisk Support Services Five-tiered support subscriptions from Sangoma for Asterisk Core components, ranging from community support (Level 1) to Level 5 SLA and Engineering support for OEMs and enterprises with negotiated response and resolution times.
• Asterisk Commercial Licensing Dual-license model offering GPLv2 open source license alongside a commercial license for users requiring proprietary modifications or distribution without GPL obligations; license fees vary depending on application and scale of use.

Quantifiable outcome

• 11,500,000 annual downloads
• +7 more outcomes

Named customers1 record

Segments5 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

Yes

API docs

API detail

Core technology

AI maturity

App detail

Integration5 records

AI capability4 records

Feature10 records

Partnerships

Five partnerships are on record, tiered core and minor.

• Sangoma TechnologiescoreStrategic or Co-development PartnerSangoma is the primary sponsor and maintainer of the Asterisk project. They provide ongoing development contributions, commercial licensing, support services, training, certification, and complementary products (FreePBX, PBXact Cloud, IP phones, telephony cards, VoIP gateways, SIP trunking). Sangoma acquired Digium (original creator of Asterisk) and holds exclusive rights to commercial licensing of Asterisk worldwide.
• AtlassianminorOthersAtlassian has generously donated their tools and services to the Asterisk open source project as a patron/donor.
• BrowserStackminorOthersBrowserStack has generously donated their tools and services to the Asterisk open source project as a patron/donor.
• Allnet ItaliaminorChannel Partner/ Reseller/ DistributorAuthorized training partner for Asterisk in Italy and value-added distributor of telecom equipment specialized in Asterisk-compliant products.
• Avanzada 7minorChannel Partner/ Reseller/ DistributorValue Added Distributor of Telecom Equipment specialized in Asterisk-compliant products and official trainer of Digium Asterisk courses.

Scale indicators8 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Genesys: Cloud contact center platform serving enterprise call center use cases that overlap with Asterisk's ACD, IVR, and queueing deployments.
• RingCentral: Cloud UCaaS provider targeting SMB and mid-market with hosted PBX, competing head-on with Asterisk-based on-premises deployments.
• Cisco Unified Communications Manager: Enterprise incumbent for IP PBX and unified communications. Competes with Asterisk in large enterprises via proprietary, hardware-tied solutions.
• Vonage: Communications platform provider offering cloud UCaaS and APIs (CPaaS) that compete with both Asterisk's on-prem PBX and Sangoma's SIP trunking services.
• Avaya: Legacy enterprise communications vendor offering proprietary IP PBX and contact center solutions that overlap with Asterisk's enterprise use cases.
• Zoom: Cloud communications platform with Zoom Phone offering hosted PBX functionality, increasingly competing with Asterisk for unified voice/collaboration workloads.
• Microsoft Teams: Cloud-native UCaaS platform displacing on-prem PBX deployments including Asterisk for voice, meetings, and collaboration in enterprises of all sizes.

Direct peers

• 3CX: Commercial PBX software (originally built on Asterisk) now offering a proprietary unified communications platform. Competes directly for SMB and mid-market IP PBX deployments.
• Kamailio: Open-source SIP server frequently deployed alongside Asterisk for carrier-grade SIP routing and VoIP infrastructure. Targets overlapping developer and service provider segments.
• FreeSWITCH: Open-source telephony platform offering similar PBX, VoIP, and media capabilities. Closest direct open-source competitor to Asterisk with overlapping protocols, codecs, and developer communities.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• GitHubgithub.com/asterisk/asterisk
• YouTubeyoutube.com/user/asteriskvideos
• Facebookfacebook.com/digiumasterisk
• LinkedInlinkedin.com/showcase/freepbx
• Xx.com/smart_asterisk

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds1 record

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Asterisk