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Configuring your firewall for 3CX

Are you considering trying out 3CX, the software IP PBX platform for Windows, and need to know what ports you may need to open/forward in your firewall? This article will give you all the information you need to get 3CX running behind your firewall. If you are not going to have any external connections such as remote phones or SIP trunks, then you can ignore all of this since there will be no need to open your firewall if you don’t need outside connections. However, if you are going to use SIP trunks or have remote phones, then you will need to know which ports to forward to your PBX system.

Remote Phones and SIP Trunks

Remote phones and SIP trunks use two sets of ports. The first port is used by the SIP protocol to establish the phone call and set up the communication. The SIP communication uses UDP 5060.

Once the SIP protocol has established the call, the audio portion of the call can begin. The audio portion of the call uses RTP to send the voice packets back and forth. Each call will require two ports to be available. Usually its recommended to forward UDP ports 9000-9049 to the PBX.

3CX Tunneling

3CX has a tunneling protocol built-in for use with the 3CX Softphone or for bridging machines together. This tunnel requires that a single port be forwarded. You will need to forward port 5090 with both UDP and TCP to your PBX server in order for the tunnel services to work properly.

Testing your setup

If you would like 3CX to test your firewall configuration, go to the 3CX Services and stop the 3CX Phone System Service and the 3CX Tunnel Service.Next, go to Settings, and Firewall Checker and let the tests run. If everything goes right, you should get a page of messages telling you if things are working properly or not. When finished, start the services back up again.

Automatically backing up your 3CX system

One thing you need to think of with running a 3CX system is making sure you have a current backup of your system. The phone system for a business is usually the single most critical system and without a current backup, you could find yourself in a real world of hurt if you have a client’s system go down and you need to get it back up and running quickly. What most people don’t know is just how easy it is to do automated backups of a 3CX system. In this article, I will show you exactly how to set up a very simple, and yet complete backup of a 3CX IP PBX system.

Getting Setup

Surprisingly enough, everything you need to do an automated backup of your 3CX system is included with the basic 3CX installation. What you may not know is that the 3CX Backup and Restore tool can be called with command line parameters so you that you can easily do a backup from a very simple batch file.


You can actually customize your backup to suite your needs. For example, you may only need to backup the configuration once a week or even once a month, but you may want CDR data and voicemails to be backed up every night. The different options available at:

  • /callrecordings
    • Backs up call recordings for extensions
  • /voicemails
    • Backs up stored voicemails
  • /voiceprompts
    • Backs up voice prompts and music on hold files
  • /callhist
    • Backs up call history tables from the 3CX database
  • /exit
    • Exit the 3CXBackup.exe program when finished

Using these parameters we can create a simple backup script and even have the backup file stored on a network share.

@echo off
echo Launching 3CX backup system…
“C:\Program Files\3CX PhoneSystem\Bin\3cxbackup” backup \\fileserver\backups\3CXBackup.zip /callrecordings /voicemails /voiceprompts /callhist /exit

Once you have this backup script you can then schedule the task using Windows’ Scheduled Tasks manager.

Taking a look at 3CX – The IP PBX Platform for Windows

In the past if you wanted to run an IP PBX platform on Windows, your only choice was to run Linux and an IP PBX like Asterisk or trixbox CE under VMWare or other virtualization method. While this would mostly work out ok, Asterisk can have issues with timing under VMWare which can cause sound problems with files being played back such as voicemail and IVR prompts.

For Windows administrators who have been looking for a real native Windows application and have been disappointed in the few lackluster products that have been available, things are about to change.

Early this year 3CX released version 7 of their IP PBX software for Windows-based systems. Version 7 was a milestone for the 3CX product in terms of functionality and reliability but was just a little lacking in some features and endpoint support. Within the next few weeks, 3CX will be unleashing version 8 which is set to really put 3CX on the map with enhanced features and third-party hardware support.

Why is 3CX Important?

Other people can tackle the Linux versus Windows debate but the fact is that most small-medium businesses run Windows exclusively and there are many thousands of IT consultants out there that don’t know and don’t want to learn Linux. While products like trixbox CE certainly opened the world of business telephony to many, many people, a solid product like 3CX being available on Windows could turn out to be an even bigger game-changer.

Is 3CX the best IP PBX platform available? No, and nobody is claiming it is….yet. Other systems out there, from companies like Digium and Fonality, have a several year head start on 3CX and while version 7 has dramatically increased the acceptance level to many resellers and integrators, there has still been a few things lacking from it. Version 8, due out soon, addresses many of these issues and brings some the feature set much closer to competing solutions.

Taking a look at 3CX

3CX runs as a set of services and uses a web interface to configuring and manage the configuration. You can either use IIS or the Cassini web server that can be installed during the 3CX setup.

3CX uses the standard SIP protocol so it will work with most every third party VoIP phone that also speaks SIP such as phones from Polycom, Aastra, snom, Cisco, and Grandstream as well as SIP trunking services from companies such as Vitelity and Bandwidth.com.

While the interface may be a simple infinite-tree GUI, it is laid out well and in a logical order making it fairly simple to use with very little training.

3CX Assistant

From a user point of view there really isn’t anything interesting about a phone system. The one thing a user interfaces with is their phone, and even those aren’t that different between the different models that are available.  One thing that 3CX brings to the mix is the 3CX Assistant, a program that melds the desktop and the phone into one handy application.

The 3CX assistant is more than just an app that shows the status of other phones, it also lets you manage incoming calls, call other extensions, make outbound calls, see other people’s status, and chat with other people in the company.

The 3CX Assistant will become an essential productivity tool. While it may not be obvious at first, the more you use it, the more you will depend upon it. Being able to see when something is available or not, chat with them, and manage calls will change the way you interact with the other employees within your company.

No more calling people who aren’t at their desk or having to go through the hassle of sending an email when all you need is a quick answer to something, just chat. Why not just use Yahoo or Microsoft Messenger? Any company that has used an outside instant messenger service knows that inevitably friends and family members end up in employee’s buddy lists. Keeping chat constrained to business purposes helps eliminates those outside distractions.


3CX licensing is based on simultaneous calls within the system and not on extensions like most other systems. This can make 3CX much more affordable than other commercial offerings. Inbound, outbound, extension to extension, and voicemail calls all count against the simultaneous calls counter. While this is rather unorthodox for a licensing model, it does mean that every version from the lowest Mini Edition to the largest Enterprise version all have the same identical feature set. There are no extra charges for call queues, bridged servers, conference rooms, or other higher end features that other systems charge extra for.

  • Mini Edition (4 simultaneous calls) $350
  • Small Business (8 simultaneous calls) $695
  • Pro Business (16 simultaneous calls) $1,250
  • Pro Business (24 simultaneous calls) $1,695
  • Enterprise Business (32 simultaneous calls) $2,250
  • Enterprise Business (64 simultaneous calls) $4,295
  • Enterprise Business (128 simultaneous calls) $7,495
  • Enterprise Business (256 simultaneous calls) $12,50

For more information and to download a free version (see comparison chart for features) for you to try out for yourself, go check out http://3cx.com.