3CX Phone System for Windows

  • Editors' rating
    7.8 Very good


  • Windows-based
  • Support for SIP phones, gateways, hosted services and trunks
  • Simple browser-based management
  • Branch office bridging
  • Free edition for small companies


  • Scalability could be an issue for large organisations
  • Limited survivability features

In many ways the 3CX Phone System for Windows is much like other IP telephony solutions in that it enables companies to replace a conventional PBX with equipment to make and receive calls using VoIP (Voice over IP). In others, however, it’s quite different, with a number of unique features that really do make it stand out.

The most obvious difference is that all you get from 3CX (or its distributor Zen Software) is software, designed to run on industry-standard PC hardware rather than the custom switches and other appliances that come with products from companies such as Cisco, Avaya, Nortel and others. By itself, that’s nothing new as there are plenty of other software-based PBX products available — including the popular open-source Asterisk package. Most of those, however, are written for Linux, whereas 3CX can be deployed on Windows — even XP or Vista for small setups. Furthermore, the preferred method of connecting to the public telephone network is via independent or hosted SIP gateways, so 3CX's software can even be run on a virtual machine, if required.

Another differentiator is the availability of a free version, as well as three more scalable commercial implementations. All can be configured to handle an unlimited number of extensions, but the free version is limited to eight simultaneous calls, as is the Small Business edition (from £268 ex. VAT). The Pro edition (from £568 ex. VAT) can process up to 16 simultaneous calls, while the Enterprise edition offers 32 for £821 (ex. VAT), upgradeable to 128 in total. The commercial versions also offer additional functionality including Microsoft Exchange integration, call recording and automatic handset provisioning, connectivity with CRM and ERP applications, plus a web portal to enable users to manage their own settings.

The 3CX PBX can connect to the PSTN via hosted SIP services and SIP trunks.

The software itself comprises a number of components, including an Apache web server and a PostgreSQL database server installed by the integrated setup routine, along with background servers to look after call routing, voicemail and other tasks. Installation is quick and easy: it took us around five minutes on a virtual machine, and we had no problems getting it working even though the components involved are far from standard Windows applications. That’s mostly down to the browser-based management console, which features wizards and templates to help you configure the product and an intuitive interface for day-to-day administration.

Top ZDNET Reviews

Adds, moves and changes are easy using the 3CX software.

Naturally you’ll need IP-enabled handsets to make and receive calls, but you can use any SIP-compatible phone or adapters to convert ordinary analogue/digital handsets to work with VoIP. These can be difficult to configure, so it was good to find detailed instructions provided on how to configure 3CX to use handsets from leading vendors such as Grandstream, Linksys and Snom. SIP softphones, such as X-Lite, can also be used, and a free 3CX softphone is included with all versions, although its functionality is limited in the free download.

A softphone application is included with the 3CX software, but you'll need a commercial license to access all of its features.

Defining a new extension takes just a couple of minutes — seconds once you’ve setup the defaults you want. Indeed, it took less than half an hour to configure our test PBX to make and receive calls between extensions, forward and transfer calls and so on. Changing or deleting users is straightforward and hot-desking a standard feature, with users able to log into their extension from any handset or softphone with a PIN code for authentication — even when teleworking.

An easy-to-configure Interactive Voice Response (IVR) facility is a standard option.

Of course you'll want to do more than just make internal calls so, having defined the extensions, the next task is to connect the PBX to the public switched telephone network (PSTN). Unlike a lot of other products, the 3CX software doesn’t include a PSTN gateway of its own, relying instead on third-party gateways, typically implemented as external appliances. These can be had with either ordinary phone or ISDN interfaces and can be difficult to configure, although templates for use with products from vendors such as Mediatrix, Linksys and others are, again, provided to help.

Alternatively it’s possible to connect to the PSTN via hosted SIP services, using the internet rather than having to rent lots of phone lines. Support for SIP trunks is also available in the latest version, along with a new 3CX-to-3CX bridge for branch office communications.

Extensions can be grouped together into hunt and other calling groups.

We found everything very easy to set up and use, and were impressed by the level of functionality provided. As well as basic call handling facilities, for example, there’s support for hunt groups (routing inbound calls to multiple extensions), music on hold and so on. Voicemail comes as standard, along with Outlook integration and a fax server. An Integrated Voice Response system ('Press button 1 for sales', and so on) facility is also included, and proved remarkably easy to configure.

In fact, our only real concern is scalability. Performance shouldn’t be a problem: we were only able to test a small setup, but given suitably specified hardware the 3CX software ought to be handle the demands of quite large organisations. However, it does rely on the use of third-party gateways and SIP services, which means that sourcing, configuring and managing large populations of these components could be an issue — especially if they're from multiple vendors. The 3CX software also lacks many of the survivability features found on other IP PBX products, although support for Windows clustering is built into the Enterprise edition.