How to configure Callcentric VOIP Service with 3cx Phone System?

What is Callcentric?

Callcentric is a service that lets you make and receive free phone calls to other Callcentric members; and to traditional phones world wide at great rates. Callcentric uses your internet connection and software on your computer or a telephone adapter to place calls using Voice over Internet Protocol (VoIP). VoIP means your calls travel from your computer or telephone adapter across the Internet and to their final destination.

What is 3cx Phone System?

3CX Phone System for Windows is a software-based IP PBX that replaces a proprietary hardware PBX / PABX. 3CX’s IP PBX has been developed specifically for Microsoft Windows and is based on the SIP standard, making it easier to manage and allowing you to use any SIP phone (software or hardware). A software-based IP PBX / PABX offers many benefits:

  • Easier to install & manage via web-based configuration interface
  • Far less expensive to purchase and expand than a hardware-based PBX / PABX
  • Improve productivity with presence, desktop based call control and extension management
  • No need for separate phone wiring – phones use computer network, easy hot desking!
  • Deliver mobility by allowing employees to work from home using a remote extension
  • Choose between popular IP hardware phones or softphones – no vendor lock in
  • Receive & make calls via the standard PSTN using VoIP Gateways or cards
  • Save on monthly call costs using SIP trunks, VoIP providers or Skype Connect!

How to install 3cx Phone System?

  • Download the package from
  • Run as administrator and install it following the onscreen instructions.
  • Language -> English, Local IP -> your LAN IP, Public IP -> Blank (leave other settings to their default)
  • Give a password.
  • In extensions, add  -> give extension number and password.
  • Click next -> Select Country and code and then follow the onscreen instructions
  • Setup VoIP providers or skip it. (Here we’ll do it later)
  • Click next -> Skip registration -> Finish
  • Now go to the administration console by typing : http://localhost:5000 and login using your username and password.
    Replace localhost by Server IP if you are managing it remotely.

How to setup Port Forwarding for 3cx Phone System?

Now, I’m going to configure proper port forwarding for the 3cx system to function properly. It will be a two step process.

1. Configure port forwarding on the router:

Here I am using DLink DIR 615 router to setup port forwarding for the server IP. Here’s the main funda :

The ports need to be forwarded are:
TCP Ports: 5001,5060,5061,5090
UDP Ports: 5060,5090,9000-9049

2Configure firewall options on your Windows System:

From Control Panel search for Firewall -> Advanced Settings -> Right click on Inbound rule -> Add new rule -> Port ->. TCP ->5001,5060,5061,5090 -> Allow connection -> Give a name to it -> Finish

From Control Panel search for Firewall -> Advanced Settings -> Right click on Inbound rule -> Add new rule -> Port ->. UDP -> 5060,5090,9000-9049 -> Allow connection -> Give a name to it -> Finish

Note : I faced severe problems with port forwarding of port 5060 with DLink DIR 615 Router. So I had to change the default port for SIP from 3cx Settings -> Network to 5050 and change router configuration accordingly. That did solve my problem but try not changing the default port.

Configure Callcentric VoIP with 3cx Phone System:

  • Login to using your username and password.
  • Now, in the left side of your dashboard, copy Callcentric #.
  • Login to your 3cx admin panel.
  • Goto VoIP Providers -> Add Provider
  • Add VoIP configurations. Note: We need to change the ports to 0 if we face problem later
  • Enter VoIP credentials
  • Configure inbound rule

For more detailed configuration and learn how to get a free US number and receive incoming calls for free watch this video:

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