Asterisk
UCaaS platforms
VoIP providers
- Features
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What is Asterisk
Asterisk is an open-source software PBX and VoIP telephony platform used to build and run IP-based calling systems. Organizations and service providers use it to implement SIP trunking, IVR, call routing, voicemail, conferencing, and contact-center style call flows on their own infrastructure or in the cloud. It is typically deployed and customized by IT/telecom teams or integrators rather than consumed as a turnkey hosted UCaaS service. Its differentiator is its extensibility (dialplan, APIs, modules) and broad interoperability with SIP endpoints and carriers.
Highly customizable call control
Asterisk provides granular control over call routing and telephony logic through its dialplan and modules. Teams can implement custom IVR trees, queues, time-of-day routing, and integration-driven workflows that are difficult to replicate in fixed-function hosted services. It supports multiple signaling and media features commonly required in enterprise voice deployments. This flexibility makes it suitable for bespoke telephony and embedded voice use cases.
Self-hosted deployment flexibility
Asterisk can run on customer-managed servers, virtual machines, or cloud infrastructure, enabling control over data residency, network topology, and security tooling. Organizations can size and tune deployments to their own capacity and redundancy requirements. This model can fit environments where hosted UCaaS constraints or regional availability are limiting. It also supports multi-tenant designs when implemented by service providers.
Broad SIP ecosystem compatibility
Asterisk interoperates with a wide range of SIP phones, softphones, gateways, and SIP trunk providers. This helps organizations avoid lock-in to a single endpoint vendor and reuse existing telephony hardware. It supports common codecs and telephony features needed for mixed environments. Interoperability is a practical advantage when integrating legacy PSTN connectivity with modern IP telephony.
Not a turnkey UCaaS
Asterisk is software infrastructure rather than a fully managed UCaaS platform with bundled carrier services, SLAs, and end-user apps. Organizations typically need to source SIP trunks, numbers, E911, and compliance capabilities separately. Ongoing operations (monitoring, patching, backups, HA design) remain the customer’s responsibility unless outsourced. This increases implementation effort compared with hosted platforms.
Requires specialized expertise
Successful deployments often require telephony engineering skills (SIP, RTP, NAT traversal, QoS) and familiarity with Asterisk configuration. Complex call flows and integrations can be time-consuming to design, test, and maintain. Troubleshooting voice quality and interoperability issues can require packet-level analysis. This can be a barrier for smaller teams without dedicated voice administrators.
UC features depend on add-ons
Out-of-the-box Asterisk focuses on telephony; broader unified communications capabilities (team messaging, meetings, modern desktop/mobile clients, analytics dashboards) are typically delivered via third-party clients, companion projects, or commercial distributions. Feature parity with packaged UCaaS offerings varies by the chosen ecosystem components. User experience consistency can be harder to achieve across mixed vendors. Reporting and contact-center features may require additional software layers.
Plan & Pricing
| Plan | Price | Key features & notes |
|---|---|---|
| Asterisk (core, open-source) | Free | Asterisk is a free, open-source communications framework — downloadable and self‑hosted. |
Pricing model: Pay-as-you-go (SIP trunk/channel based via SIPStation) Free tier/trial: Asterisk.org references a 21-day free SIP trunking trial for FreePBX users. Example costs: SIP trunks for Asterisk — starting at $19.99 per month per channel (as stated on asterisk.org). Discount options / notes: Asterisk.org indicates month-to-month and yearly plans are available for SIP trunking; trunk groups and concurrency bursting are mentioned for scale and cost management. Commercial support for Asterisk is offered (referenced), but no pricing is listed on asterisk.org.
Seller details
Asterisk (open-source project) sponsored by Sangoma Technologies Corporation
Markham, Ontario, Canada
1999
Open Source
https://www.asterisk.org/
https://x.com/asterisk
https://www.linkedin.com/company/asterisk/
