Take 3CX PBX To The Next Level !


To be able to make outbound calls on the PSTN you will have to configure at least one SIP trunk / VoIP Provider or VoIP Gateway. 

VoIP / SIP Trunk providers “host” phone lines and replace the traditional telco lines. VoIP providers can assign local numbers in one or more cities or countries and route these to your phone system. In most cases they also support number porting. Typically SIP trunks are cheaper than traditional PSTN lines. However, be aware that each VoIP call requires bandwidth. 

3CX supports both registration based VoIP providers (Trunk logs on with username and password) and IP based trunks (PBX is linked to the Provider based on your public IP). When connecting to TelecomsXChange SIP Providers please use IP-Based trunks (no registration is required).

If you still have traditional PSTN/Phone lines, or prefer to use those, you can connect them to 3CX using VoIP Gateways. A VoIP gateway is a device which converts telephony traffic into data, so that it can be transmitted over a computer network. In this manner PSTN/telephone lines are “converted” to a SIP trunk, allowing you to receive and place calls via the regular telephony network. VoIP Gateways exist for analog lines as well as BRI, PRI/E1 lines and T1 lines. The VoIP Gateway will bundle these lines / ports into a single SIP trunk inside 3CX.

Configuring a TelecomsXCHange VoIP Provider / SIP Trunk

Step 1: Create a Buyer Account with TelecomsXChange

First, you need to have an account with TelecomsXChange . 3CX supports most popular SIP based VoIP Providers including TelecomsXChange SIP Platform for connecting to many VoIP providers in one account.

Step 2: Whitelist your 3CX PBX IP in TelecomsXChange Buyer account

To whitelist your 3CX PBX IP in TelecomsXChange please follow below steps:

    1. Logging in to TelecomsXChange buyer account 

    2. Click on Accounts tab     

    2. Add new account 

    4. Enter 3CX Public IP Address.

    5. Save and Close.

Step 3: Conduct the Firewall Test

3CX will prompt you to conduct a Firewall Test. Frequently, the internet facing firewall sitting between 3CX Phone System and the VoIP provider is not correctly configured or is not able to correctly route VoIP traffic. To check the firewall configuration, it is important to perform a firewall check using the inbuilt firewall checker. To do this:

  1. In the 3CX Management Console, go to the System Status page.
  2. In the section “PBX Status” select the “Firewall Check” entry.
  3. Click Run.” 
  4. Ensure that the tests for the SIP Port (default port 5060), and the Audio Port range (default ports 9000-9255) pass. 
  5. If the firewall check fails, you must go to your firewall and troubleshoot why the test failed.

Note: 3CX does not provide specific firewall configuration support. Configurations for popular firewalls can be found here.

Step 4: Add the VoIP Provider Account in 3CX Phone System

After you have created the VoIP provider account, you will need to configure the account in 3CX Phone System. To do this:

  1. In the 3CX Management Console menu, select SIP Trunks” > Add SIP Trunk.”
  2. Select the Country that the VoIP provider operates in.
  3. Select the “Generic” option in Country drop down menu and then choose between  “Generic VoIP Provider,” or “Generic SIP Trunk.” 
  4. Enter the Main Number assigned to this SIP Trunk. If you just have DIDs and no main number you can select one of the DIDs as the main number. Click OK.” The SIP Trunk will be created and a new dialog will open.
  5. Enter a name for this VoIP provider account. The SIP server hostname or IP = sip01.telecomsxchange.com” and optional “Outbound Proxy = empty” will be pre-filled. Compare these with the details you have received from your VoIP provider and check that these are indeed correct. 
  6. Specify the number of simultaneous calls” your provider allows, set it to 200 by default.
  7. In Authentication,” specify whether authentication is based on IP or based on Account/Registration. If you selected a template, this will be automatically pre populated and you must leave as is. If IP based, the password will be greyed out, since authentication is linked to your IP. The outbound or inbound only are not applicable in most cases and can be ignored.
  8. Specify how calls to the main number should be routed. The routing configured here will be for calls matching the main number.
  9. If you have DID numbers, you will need to specify these in the DIDs tab. Click on the “DIDs” tab and add the DID numbers associated with this account. The DID will be created and linked to the operator extension. You can change this later from the “Inbound Rules” node by adding an inbound rule for the DID and routing to the desired destination. (If you dont have a DID number and you want to get one or more for FREE please click here)
  10. In the Caller ID tab, add the caller ID you wish to have appear on outbound calls.
  11. Click OK” to save the trunk settings.