Configuring 3CXPhone for iPhone with 3CX VoIP Tunnel
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Configuring 3CXPhone for iPhone with 3CX Tunnel

This guide is useful for remote workers that want to connect 3CXPhone for iPhone to 3CX Phone System IP PBX when they are at home, or out of the office. To avoid NAT problems, audio or network issues, iPhone users have the possibility to download 3CX VoIP Tunnel which is a separate app on the Appstore. This will  tunnel signalling and voice eliminating firewall issues completely.


Step 1: Configure 3CX VoIP Tunnel

1. Tap on the 3CX Tunnel icon located on the home screen

2. Configure the following fields according to the settings of your 3CX Phone System. You will need to contact your 3CX Administrator for this information:

  • Remote Tunnel IP: Enter the 3CX Phone System Public (external) IP Address.
  • Remote Tunnel Port: This is the port that the 3CX Phone System tunnel service is listening for requests. Default is 5090.
  • Remote Tunnel Password: Enter the 3CX Tunnel Password.

3. Click on Start. 3CX VoIP Tunnel will start in the background, create a tunnel connection to 3CX Phone System Tunnel Service and proxy all SIP and Audio traffic through one port. You should see Status: Connected.

Step 2: Connect through 3CX Tunnel

1. Configure 3CXPhone for iPhone using Auto Provisioning.

2. To make a connection through the 3CX Tunnel, you need to enable the relevant option in the 3CXPhone settings. From the Dial Screen press “More” > “Settings” > “Accounts” > “Select your account” > “Server Settings” section > Turn on “Use 3CX Tunnel when Out of Office”.

2. Return to the Dial Screen and tap In Office.


  • In Office – This is used to connect your extension to 3CX Phone System when you are In Office (In the same network as that of 3CX Phone System).
  • Out of Office Tunnel – This is used to connect your extension to 3CX Phone System when you are Out of the Office, for example at home. For this connection the 3CX VoIP Tunnel is required to avoid NAT issues and audio problems.

3. Select “Out of Office”.

Note: 3CX Tunnel should only be used in networks that prevent VoIP calls. Revert the “Use 3CX Tunnel when Out of Office” setting when your network allows VoIP calls.