Receive Faxes and Calls through the Same Line

If your company only has a single telephone line, you can have fax and voice call on the same line. This topic describes how to receive faxes on an analog fax machine through a shared line.

Background information

Generally, we use an IVR to receive fax and voice on the same line. When the call is answered, the PBX detects fax signal throughout the duration of the call.


Before you receive faxes from an analog fax machine, perform the following tasks:
  1. Install S2 module or SO module on the PBX.
  2. Connect fax machine to FXS port of the PBX.

    In this topic, we connect fax machine to FXS port located in Span2-Port3.

Step1. Assign an extension to the analog fax machine

  1. Log in to PBX web portal, go to Extension and Trunk > Extension.
  2. Click Add.
  3. In the Basic section, select FXS Extension from the Extension Type drop-down list.
  4. In the FXS Port drop-down list, select the FXS port to which the fax machine is connected.

    As the following figure shows, select fax port Span2-Port3.

  5. Click Save and Apply.

Step2. Set up an inbound route for receiving faxes

  1. Go to Call Control > Inbound Route, click Add.
  2. In the Name field, enter an inbound route name to help you identify it.
  3. Set the DID Pattern through which this route pass the incoming call.

    As the following image shows, set the trunk number as DID pattern.

  4. Select the trunk that supports to receive faxes.
    Note: If you choose a SIP trunk to receive faxes, you need to enable T.38 Support for this trunk.
  5. In the Default Destination drop-down list, select IVR.
  6. Set the destination for receiving the faxes.
    1. Turn on Fax Detection.
    2. In the Fax Destination drop-down list, select Extension.
    3. Select the extension that you have assigned for fax machine.

      As the following figure shows, set the assigned extension 2185 to the fax machine.

  7. Click Saveand Apply.


When the customer places a call to your company, the call is automatically answered by IVR. The customer can follow the voice menu to access the desired department, send fax after negotiation or send the fax directly.

  1. The customer sends a fax to your company (5503301).

    The originating fax machine sends a fax signal to system to indicate that this is a fax call.

  2. The PBX detects the fax signal, automatically forwards the call to the extension (2185) you have assigned to your fax machine.
  3. Receive fax on your fax machine.