If you experience problems when faxing over VoIP, try the following options:

  • Change the fax speed to a lower speed. 

    1. From the printer control panel, press Home.
    2. Select Fax Settings, then press OK.
    3. Select Fax Speed, then using the left and right arrow buttons to change the speed; for example, "Slow (9.6K)", then press OK.
  • Select a standard resolution to reduce the amount of information that is transmitted.

    1. From the printer control panel, press Home.
    2. Select Send Fax, then press OK.
    3. Select Fax Options, then press  OK.
    4. Select Resolution.
    5. Select Standard for the resolution, then press OK. 
  • Turn Error Correction Mode (ECM) off.
    NOTE: ECM off may result in a lower quality document.  
  1. From your printer control panel, press Home.
  2. Select Fax Settings, then press OK.
  3. Select Error Correction.
  4. Make sure ECM is set to Off, then select OK to save the settings.
  • Contact your phone service provider to increase the allocated bandwidth and transmission block lengths to allow better data communication, if possible.

NOTE: Fax over VoIP can cause problems. We recommend that you keep a standard phone line (POTS) for reliable and consistent faxing, especially if you are in one of the following categories:

  • You or your business depends heavily on faxing.
  • You or your business needs to fax highly detailed documents, such as legal contracts or images.
  • Your fax documents have many pages.