How to Configure a Linksys WRT54GC Router with the 3CX Phone System


This document describes the configuration of a Linksys WRT54GC for the use with 3CX Phone System.

Linksys WRT54GC


In general the LinkSys WRT54GC routers are know to work correctly and can be used as gateway in front of a 3CX Phone System to connect Voip Provider, direct Remote Extensions (STUN) and 3CX Tunnel connections.

The status of this type of firewall is “Supported”.
Nat Type: Not tested 


Configuration of the firewall will never be carried out by the 3CX Staff at any point and must be made by the System-Administrator of the company. You must understand the risk of opening ports to the World Wide Web. Read for more information and agree with the terms stated. The provided guide is based on the best known effort to configure the device(s). 3CX is not liable for any misguidance may made in this guide.

Configuring the Linksys WRT54GC wireless router

1. Login to the web interface of the Linksys router using a web browser.
2. Click on the tab “Applications and Gaming”.
3. Click on the tab “Port Range Forward”.
4. For an always up to date list of the ports that need to be open check “Firewall & Router Configuration“, as the ports may depend on the version you are using.
Enter the following information:
• Application: Enter the name of the rule.
• Start: The start number of the port range.
• End: The end number of the port range. If you wish to open one port enter the port number specified in the “Start” field.
• Protocol: Choose on which protocol the rule should apply. TCP, UDP, or Both.
• IP Address: Enter the internal IP of the 3CX Phone System.
• Enable: Check the box to enable the rule.
Linksys WRT54GC

5. Press “Save Settings” to apply your new configuration.


Run the 3CX Firewall Checker to validate the setup from the 3CX Phone System Management Console Settings > Firewall Checker. All tested ports must return green / working.