Sending faxes over IP can be tricky without the right setup, but with T38Fax and VitalPBX, you can achieve reliable faxing through the T.38 protocol. In this guide, we’ll walk you step-by-step through setting up T38Fax with VitalPBX so you can send and receive faxes seamlessly.
If you don’t already have a T38Fax account, get your free trial at https://www.t38fax.com/.
You’ll also need the Virtual Faxes add-on installed in VitalPBX to send faxes.
Along the way, we’ll introduce the new Routing Method field, available in VitalPBX version 4.5.1-2 or later, which allows you to send faxes through a specific trunk endpoint to guarantee T.38 negotiation.
Creating the T38Fax Trunk in VitalPBX
First, we’ll set up the trunk that connects VitalPBX to T38Fax. In the VitalPBX menu, navigate to PBX → Calls Routing → Trunks and configure your trunk as shown in the screenshots below.
Defining the Outbound Route for Fax Calls
Next, create a route that directs fax calls to T38Fax. Go to: PBX → Calls Routing → Outbound Routes and Define the Route Patterns that match the numbers you’ll be faxing to. Assign the T38Fax trunk as the selected trunk for this route.
Creating the Fax Device
This is where the new Routing Method comes into play. Navigate to: PBX → Virtual Faxes → Fax Devices and create a new fax device setting up the Routing Method to Trunk (this option is available only in VitalPBX version 4.5.1-2 or later) and select the T38Fax trunk as the endpoint.
By sending faxes through a specific trunk, you ensure that T.38 negotiation occurs directly with the trunk provider, increasing reliability and compatibility.
Sending a Fax Using Virtual Faxes
With everything in place, sending a fax is easy. Go to: PBX → Virtual Faxes → Send Fax, select the Fax Device you just created, upload your document and press Send. VitalPBX will route the fax through T38Fax, using T.38 for optimal transmission.
Conclusion
By integrating T38Fax with VitalPBX and using the Routing Method field in VitalPBX version 4.5.1-2 or later, you can send faxes directly through a trunk endpoint, ensuring reliable T.38 negotiation and smoother transmissions.
With the Virtual Faxes add-on, your fax communications stay fully integrated within VitalPBX, eliminating the need for additional hardware or software.
