License & Deployment Mix: 10 tools – 6 OSS, 4 commercial, 3 SaaS (self-host-first; most run on-premises or as an appliance).
PBX and IP-telephony platforms – the systems that run an organisation’s phone service: SIP call routing, extensions, IVR/auto-attendant, voicemail, call queues/centre features, and trunking to carriers.
This category covers the PBX platforms, distributions, and SIP servers themselves – Asterisk- and FreeSWITCH-based distros (FusionPBX, Issabel, Wazo, VitalPBX), pure SIP servers (Kamailio, OpenSIPS), and commercial appliances/systems (Grandstream UCM, Yeastar, Sangoma Switchvox). The core engines (Asterisk, FreeSWITCH) and the meeting/UC clients and hosted-voice suites (3CX, RingCentral, 8x8, Zoom, Webex) are evaluated under Unified Communications.
What a PBX Platform Covers
- Call routing (SIP) – registrars, dial plans, and inbound/outbound routing across extensions and carrier trunks (SIP/PRI).
- Telephony features – IVR/auto-attendant, voicemail, ring groups, call queues, recording, and conferencing.
- Trunking & interop – SIP trunk providers, codecs, NAT traversal, and session border control.
- Management – web admin for extensions, devices (provisioning), and reporting; multi-tenancy for MSPs.
- Deployment – on-premises (bare metal / VM), turnkey appliance, or a vendor-hosted cloud PBX.
The field splits into open-source platforms built on Asterisk or FreeSWITCH, standalone SIP servers for large-scale routing, and commercial appliances or hosted systems. Open-source options dominate self-hosting; commercial offerings lead on turnkey hardware and support.
The information on these pages was researched by a combination of human review and large language models. To suggest an addition or correction, please contact us. Prepared by Rhodium Systems Inc., author of the ResorsIT platform — a unified IT operations management platform for IT teams and MSPs that integrates a curated suite of open-source, commercial, and SaaS applications into a single system with shared identity, single sign-on, access control, and a common audit trail. Use this catalogue only as a starting point for your own research, and review any tool carefully against your own requirements before relying on it. Catalogue data version 2026.197.
Comparison
Cross-tool comparison of PBX platforms, distributions, and SIP servers.
Overview Comparison
| Tool | Type | Engine | License | Deployment |
|---|---|---|---|---|
| FusionPBX | PBX platform | FreeSWITCH | MPL-1.1 | Self-hosted |
| Issabel | PBX distribution | Asterisk | GPL-2.0 | Self-hosted / appliance |
| VitalPBX | PBX platform | Asterisk | Proprietary (free tier) | Self-hosted / appliance / cloud |
| Wazo Platform | Programmable UC | Asterisk | GPL-3.0 | Self-hosted |
| Kamailio | SIP server | native SIP | GPL-2.0 | Self-hosted |
| OpenSIPS | SIP server / SBC | native SIP | GPL-3.0 | Self-hosted |
| Grandstream UCM | IP PBX appliance | Asterisk | Proprietary | Appliance |
| Yeastar P-Series | PBX system | proprietary | Proprietary | Appliance / software / cloud |
| Sangoma Switchvox | IP PBX / UC | Asterisk | Proprietary | Appliance / cloud |
| sipXcom | UC system | native SIP | LGPL-2.1 | Self-hosted |
Capabilities
| Tool | Multi-tenant | Call Centre / Queues | Provisioning UI | Best For |
|---|---|---|---|---|
| FusionPBX | Yes | Yes | Yes | MSPs hosting many tenants on FreeSWITCH |
| Issabel | Limited | Yes | Yes | All-in-one Asterisk PBX with a console |
| VitalPBX | Yes | Yes (add-on) | Yes | Commercially-backed Asterisk PBX |
| Wazo Platform | Yes | Via API | Yes | Developers/operators building on an API |
| Kamailio | N/A | N/A | No (config) | Carrier-scale SIP routing / registrars |
| OpenSIPS | N/A | N/A | No (config) | SIP load balancing and session border control |
| Grandstream UCM | No | Yes | Yes | Turnkey SMB hardware PBX |
| Yeastar P-Series | No | Yes | Yes | SMB with appliance + Microsoft 365 integration |
| Sangoma Switchvox | No | Yes | Yes | Turnkey commercial PBX with support |
| sipXcom | Limited | Basic | Yes | Native-SIP UC without an Asterisk core |
Suitability Summary
- Best OSS multi-tenant (MSP): FusionPBX (FreeSWITCH) or Wazo Platform.
- Best OSS all-in-one PBX: Issabel; VitalPBX where commercial backing is wanted.
- Best SIP infrastructure at scale: Kamailio (routing/registrar) and OpenSIPS (load balancing / SBC).
- Best turnkey appliance: Grandstream UCM, Yeastar P-Series, or Sangoma Switchvox for organisations that want vendor hardware and support.
For the core telephony engines (Asterisk, FreeSWITCH) and hosted-voice and meeting suites, see the Unified Communications category.
Tools
13 tools.
Asterisk
Asterisk is the foundational open-source telephony framework, originally created by Mark Spencer at Digium (now Sangoma Technologies).
License: GPL-2.0-only (OSS) · Kind: web · Deploy: docker · SSO: none
Evaluated under Unified Communications.
FreePBX
FreePBX is a widely deployed open-source PBX management framework built on Asterisk, providing a web GUI and modular system for extensions, IVR, queues, call recording, and SIP trunk management.
License: GPL-3.0-only (OSS) · Kind: web · Deploy: docker · SSO: none
Evaluated under Unified Communications.
FreeSWITCH
FreeSWITCH is a scalable open-source telephony platform designed from the ground up as a general-purpose communications engine, not just a PBX.
License: MPL-2.0 (OSS) · Kind: web · Deploy: docker · SSO: none
Evaluated under Unified Communications.
FusionPBX
FusionPBX is an open-source, multi-tenant web GUI and management platform built on the FreeSWITCH engine for running a full-featured VoIP PBX.
License: MPL-1.1 (OSS) · Kind: web · Deploy: native, docker · SSO: none
Grandstream UCM
Grandstream UCM is a line of on-premises IP PBX appliances providing voice, video, conferencing, and unified communications for small and medium businesses.
License: Proprietary (proprietary) · Kind: hybrid · Deploy: appliance · SSO: none
Issabel
Issabel is an open-source unified communications distribution built around Asterisk, bundling a PBX, email, fax, and collaboration tools with a web console.
License: GPL-2.0-only (OSS) · Kind: web · Deploy: native, appliance · SSO: none
Kamailio
Kamailio is a high-performance open-source SIP server (proxy, registrar, router) used to build large-scale VoIP, presence, and real-time communication infrastructure.
License: GPL-2.0-only (OSS) · Kind: service · Deploy: native, docker · SSO: none
OpenSIPS
OpenSIPS is an open-source SIP server and session border controller for routing, load balancing, and managing high-volume VoIP and real-time communications traffic.
License: GPL-3.0-only (OSS) · Kind: service · Deploy: native, docker · SSO: none
Sangoma Switchvox
Sangoma Switchvox is a commercial Asterisk-based IP PBX and unified communications system offered as an on-premises appliance or a hosted cloud service.
License: Proprietary (proprietary) · Kind: hybrid · Deploy: appliance, native, saas · SSO: none
sipXcom
sipXcom is an open-source unified communications system built on a native SIP architecture, providing PBX telephony, presence, and conferencing with a web admin UI.
License: LGPL-2.1-only (OSS) · Kind: web · Deploy: native · SSO: none
VitalPBX
VitalPBX is a commercial Asterisk-based PBX platform (with a free community edition) offering a web GUI, multi-tenancy, call centre features, and add-on modules.
License: Proprietary (proprietary) · Kind: web · Deploy: native, appliance, saas · SSO: none
Wazo Platform
Wazo Platform is an open-source, API-driven programmable telephony and unified communications stack built on Asterisk, aimed at operators and integrators.
License: GPL-3.0-only (OSS) · Kind: web · Deploy: native, docker · SSO: none
Yeastar P-Series
Yeastar P-Series is a commercial PBX system available as an appliance, software, or cloud service, with call centre, UC, and Microsoft 365/LDAP integrations.
License: Proprietary (proprietary) · Kind: hybrid · Deploy: appliance, native, saas · SSO: none
