These names are not five competing dialers. ViciBox is the official installation image for VICIdial, so comparing them is comparing a program with its installer. GoAutoDial is a separate open-source contact center suite that began as a VICIdial distribution. FreePBX and Issabel are PBX packages built around Asterisk, the telephony engine underneath VICIdial as well. Here is what each one is, with sources.
Last reviewed by the VoiceOI team
ViciBox is not an alternative to VICIdial. It is the official installation image that installs VICIdial, so "VICIdial vs ViciBox" compares a program with its installer.
GoAutoDial is a separate open-source contact center suite. It began as a VICIdial distribution called VicidialNOW, was renamed, and says it has no relationship with the Vicidial group.
FreePBX and Issabel are PBX packages built around Asterisk, the telephony engine that VICIdial also uses. They are phone-system software first; Issabel's documentation says predictive dialing modules can be added.
VoiceOI adds AI voice bots to a floor that already dials. It works with VICIdial as remote agents and with Asterisk and FreePBX setups over SIP.
What each one is, in the words of its own project or a neutral reference.
| Name | What it is | Built for outbound campaign dialing? | Relationship to VICIdial |
|---|---|---|---|
| VICIdial | "Open-Source Contact Center Solution" for inbound and outbound calls, email and chat (VICIdial Group). Uses Asterisk as its telephony engine. | Yes. The VICIdial Group says it has "a full featured predictive dialer" (open-source page). | The product itself. |
| ViciBox | "The official installation image for the ViciDial Call Center Suite," based on openSUSE Leap (ViciBox docs). | It installs VICIdial. It is not a separate dialer. | Official installer, with support through the ViciDial Group. |
| GoAutoDial | "The next generation open source omni-channel contact center suite" (its README). Formerly VicidialNOW. | Yes. Its FAQ calls it "a complete open source dialer system" (FAQ). | A separate project. Its FAQ says it is "in no way related to the Vicidial group", yet its README still lists Vicidial among its components. |
| FreePBX | A "web-based open-source graphical user interface (GUI) that manages Asterisk" (Wikipedia). | A phone-system management layer, not described as a campaign dialer. | Unrelated project. Both are built around Asterisk. |
| Issabel | "Open-source unified communications PBX software," a fork of Elastix (Wikipedia). | A PBX. Its documentation notes that modules providing predictive dialing can be added. | Unrelated project. Also built around Asterisk. |
| Asterisk | "A software implementation of a private branch exchange (PBX)" (Wikipedia). | No. It is the telephony engine that the others on this page are built on or around. | The engine VICIdial is designed to run on top of (VICIdial wiki). |
Quotations are from each page as read on October 1, 2026. Features change between versions, so check the project's own documentation for the version you plan to run.
VICIdial is not an alternative to Asterisk; it is built on it. The VICIdial wikisays: "VICIDIAL is a software suite that is designed to interact with the Asterisk Open-Source PBX Phone system to act as a complete inbound/outbound contact center suite with inbound email support as well," and that its applications are "designed to run on top of almost any version of Asterisk so no messing around with the Asterisk source code is necessary."
Wikipedia defines Asterisk as "a software implementation of a private branch exchange (PBX)", released under the GPLv2 with additional licenses available from Digium and owned by Sangoma Technologies since 2018 (Wikipedia: Asterisk). In short, Asterisk places and connects the calls, and VICIdial adds the contact center layer on top: campaigns, lead lists, dial methods, agent screens and reports. FreePBX, Issabel and GoAutoDial also build around Asterisk.
This one is a mix-up, not a choice. The ViciBox documentationsays: "ViciBox is the official installation image for the ViciDial® Call Center Suite. Official support is available through the ViciDial Group," and that it is based upon the openSUSE Leap distribution. A reply on the VICIdial forum put the difference in two sentences in 2014: "ViciDial is software. ViciBox is a self-installing Linux distribution that installs ViciDial" (forum thread).
So the real question is how you will install VICIdial: from the ViciBox image, which is the official route, or by building the packages yourself on another system. The ViciBox documentation covers installation and hardware sizing; our VICIdial cost guide covers what running it costs.
GoAutoDial's own FAQanswers the history question directly. Asked whether GOautodial is the same as VicidialNOW, it says: "Yes. We renamed the project to 'GOautodial' since the word 'Vicidial' is a registered trademark. The name change was necessary since GOautodial evolved from being more than just a Vicidial distribution. It's now a complete open source dialer system." Asked whether it is related to the Vicidial group: "No! GOautodial is in no way related to the Vicidial group."
The project's READMEcalls it "the next generation open source omni-channel contact center suite," lists Asterisk and Vicidial among its components, and says it is released under the AGPLv2 license. VICIdial itself is released under the GPLv2 up to version 2.0.4.1 and the AGPLv2 since (VICIdial license page). In short: two open-source contact center suites with a shared history, run by separate teams. Which fits depends on the features you need and on who can support it for you, so test both against your own campaigns.
Wikipedia describes FreePBX as "a web-based open-source graphical user interface (GUI) that manages Asterisk, a voice over IP (VoIP) and telephony server," maintained by a community with Sangoma Technologies Corporation as the primary developer organization and licensed under the GPLv3, with commercial modules available (Wikipedia: FreePBX). It manages the phone system, with modules such as call queues, voicemail and routing.
VICIdial sits at a different layer. It is a contact center suite built on Asterisk, which the ViciBox documentation calls "the telephony engine used in ViciDial" (ViciBox docs). On top of that engine it adds campaign dialing, lead lists, dial methods and agent screens. That is why "VICIdial vs FreePBX" is less a head-to-head than a question of whether you need a phone system or an outbound campaign dialer.
Wikipedia describes Issabel as "open-source unified communications PBX software, providing user-friendly web-based configuration, management, and reporting for telephony." It emerged as a fork of the open-source versions of Elastix after 3CX acquired that project, is based on Elastix, Asterisk, FreePBX and other components, and is released under the GPL. The same article notes that "modules providing predictive dialing can be added" (Wikipedia: Issabel).
So Issabel starts as a PBX and can be extended toward outbound dialing, while VICIdial starts as a contact center suite with campaign dialing built in. If you are comparing them, list the campaign features you need (lead lists, dial methods, agent screens, dispositions, reporting) and check each one against the Issabel install you would actually run.
Four situations, and the name that fits each.
VoiceOI does not replace any of these systems. On VICIdial, bots join your campaigns as remote agents, VICIdial keeps your lists and reports, and each call outcome is written back as a disposition (VICIdial AI voice bot, VICIdial AI integration guide). Asterisk and FreePBX-based setups connect over SIP (Asterisk AI voice bot), and the built-in bot dialer works through any SIP carrier (SIP trunk for AI voice agents).
VoiceOI has not published setup guidance for GoAutoDial or Issabel, and it does not list supported Asterisk or FreePBX versions. If you run one of them, tell us what you run before you plan around it.
Every quotation above comes from one of these pages. Links to projects and references outside VoiceOI that are not official VICIdial sources are marked nofollow.
Short answers on how these projects relate and what VoiceOI connects to.
No. Asterisk is an open-source PBX, which Wikipedia defines as "a software implementation of a private branch exchange (PBX)". The VICIdial wiki says VICIdial "is designed to interact with the Asterisk Open-Source PBX Phone system to act as a complete inbound/outbound contact center suite" and runs "on top of almost any version of Asterisk". Asterisk handles the calls; VICIdial adds campaigns, lead lists, agent screens and reports.
No. VICIdial is the contact center software. ViciBox is the official installation image that installs it: the ViciBox documentation calls it "the official installation image for the ViciDial Call Center Suite", and a 2014 forum reply put it as "ViciDial is software. ViciBox is a self-installing Linux distribution that installs ViciDial."
No. GoAutoDial began as VicidialNOW, a VICIdial distribution, and was renamed because "Vicidial" is a registered trademark. Its own FAQ says it has evolved into a complete open-source dialer system and is "in no way related to the Vicidial group", although its README still lists Vicidial among its components.
FreePBX is described as a web-based open-source GUI that manages Asterisk. It is a phone-system layer rather than a purpose-built campaign dialer like VICIdial, which adds lead lists, dial methods, agent screens and call dispositions.
Issabel is open-source unified communications PBX software, a fork of Elastix. Its documentation notes that modules providing predictive dialing can be added, so check what a given install includes before you compare it with a dialer suite.
Their software is open source: VICIdial has no license fee (GPLv2, then AGPLv2), GoAutoDial's FAQ says it is free and its README says AGPLv2, FreePBX is GPLv3 with commercial modules available, and Issabel is GPL. Servers, carrier minutes and admin time still cost money.
Bots join VICIdial campaigns as remote agents, and VoiceOI works with Asterisk and FreePBX-based setups over SIP; it does not publish a supported-version list. VoiceOI has not published setup guidance for GoAutoDial or Issabel, so tell us what you run before you plan around it.