Fax over VoIP - Epson All-in-One Printer/Fax Machines.

Epson All-in-one Printers/Fax machines (later ones) may not have the ideal (9600 baud) rate setting, but can be lowered to 14,400.  Later all in ones are faster machines, some standard at 33,600, but do have setting adjustments to lower the speed to 14,400 baud, which depending on the quality of your connection could work.  The ideal setting is 9600 as faster speeds require much more stable (very minimal jitter, packet loss, etc.) connections, but lacking this setting making the baud rate as slow as possible is the next best thing.

Settings on Epson NX300/305 series All-In-One Printer/Fax for VoIP.

                   

• Press the Copy/Fax button to select Fax Mode.
• Press the Menu button.
• Using the left or right navigation select  Fax Setting, then press OK.
• Using the left or right navigation select  Communication, then press OK.
• Under ECM select Disable (Off).  Under V.34, (This setting indicates the speed at which you transmit faxes; On is 33,600 bps and Off is 14,400 bps.), select Off.

VoIP Fax settings on Epson Workforce 840 All-In-One Printer/Fax.

• Press the Up Arrow and select Setup
• Scroll using either the left or right navigation Arrows and select Fax Settings. 
• Then select Communication.
• Under ECM select Off.
• Using V.34 which is the default speed setting 33,600 baud, select Off for 14,400 baud.