ECOSYS M6635cidn fax errors

[kuby]

We have a M6635cidn that keeps getting U01011, U01026 and U01056 errors when faxing. It is hooked up thru a Fax Modem and the internet.
The setting are:
Port 1:
Communication Control 1:
TX start speed: 14400 bps/V17
RX start speed: 14400 bps
TX echo: 300
RX echo: 75

Port 1:
Communication Control 2:
ECM TX: On
ECM RX: On
CED FREQ.: 2100

Port 1:
Communication Control 3:
DIS 4BYTE: Off
NUM. OF CNG(F/T): 2 Time

Port 1:
Communication Control 4:
V.34: On
V.34-3429Hz: On
DIS 2RES: Once
RTN CHECK: 15%

Is there something I need to check, turn Off/On ? The Fax/modem has been replaced, printer firmware is up to date, line is clear.

Thanks

[copiertec]

You say the line is clear. Did the line provider physically check the line? Did this just start happening?

[sparkycivic]

It is hooked up thru a Fax Modem and the internet.

The fax modem is internal to the 6635cidn.

I need to know more about the telephone line being used...

[kuby]

It is a Spectrum Fax/Modem connected to the internet and then to the machine and faxes with a digital signal.

[scottybbb]

Try turning V34 off. You may need to reduce the TX and RX speeds lower than 14400bps.

[tmaged]

Fax over VOIP.pdf
Use this for the settings and make sure it's using a 2 wire line.