Tutorials: SIP Trunk Setup (V20)

Required Access: 3CX

Last Updated: 5/21/2025

Enter your credentials.

Click on the "Admin" button on the lower left side of the screen.

Select the "Voice & Chat" tab.

Select the "+ Add SIP Trunk" button, then click on "Add Trunk" from the drop-down menu.

Get the SIP Trunk’s information (retrieve it from the Voxtelesys Portal):

• Name: Choose your name for the trunk
• Country: US
• Trunk: Voxtelesys

Make sure that the following:

• Registrar/Server: Confirm it shows 3cx.pstn.voxtelesys.net
• Auto Discovery: Make sure the first Auto discovery is checked.
• Outbound Proxy: Make sure outbound proxy is blank.
• Port: Set port behind outbound proxy to 5060 if not prefilled.
• Second Auto Discovery: Make sure second auto discovery is unchecked.

Enter the following:

• Main trunk number: Fill in the Voxtelesys SIP Trunk number in the E164 format.
• Authentication ID (SIP User ID): From Voxtelesys
• Authentication password: From Voxtelesys

Default Outbound Caller ID:

Set the number in the E164 format as the example shows.

Optional - Add or import more DID numbers here:

Optional - Check Enable SMS here:

Save and verify that the Voxtelesys SIP Trunk registered.