I have this HP 5610 all-in-one fax machine and have always had the issue of faxes failing either receiving or sending ever since I began using VOIP at home about 5 years ago. I have played with the setting of the fax machine and turned off error correction and etc and it has improved but mostly still fail. Voice quality if fine and my network has no problems that I can tell. I have read on the internet that this is a common issues with VOIP and fax machines. This issue is also happening at a friends house as well. Help!

I do not use VOIP but can probably provide somewhat of an explanation. VOIP uses audio compression techniques (codecs) that are designed for human speech. An analog FAX machines beeps and chirps are outside human speech and so transmissions will fail since the codec will cut out signals outside the desired band.

It depends on the VOIP provider and codecs used. A quick google indicated some people do not have problems with certain providers. There are also protocols for FAXing over VOIP but do not know what providers implement it. Using 9600 instead of 14.4 baudrate might help.

Double posted for some reason.....

I have adjusted the speed and that seems to help but I need to see if my voip provider will allow me to change the codec settings. I was doing some reading:

http://www.voipmechanic.com/faxingis...herdevices.htm

and it they recommend setting the codecs to G711 instead of G729. I will look into this further. Many thanks