Fax problems with VOIP

I have INTALK as my VOIP provider, I have a Brother MFC4800 fax, Comcast as my IP. When I try to send a fax, it dials and starts to complete but does send, result is BUSY. I have talked to Intalk and Brother, but to no avail. Any suggestions to help fix this problem?
Thank you.

 

to my understanding voip and faxes dont work well. I was working on a computer for some one who uses dial up still there was no way that it would connect to the dial up provider over my voip this link my explain it better
http://www.soft-switch.org/foip.html

 

http://chris.pirillo.com/how-to-fax-over-voip-on-the-internet/

For this article, I couldn't get the main site to load so here is google's cache
http://74.125.47.132/search?q=cache...p"&cd=20&hl=en&ct=clnk&gl=us&client=firefox-a

The main site - maybe it will load later.
www.ideamarketers.com/?How_to_use_Fax_More_Efficiently_over_VoIP&articleid=436724

 

I know this isn't exactly what you had asked but... have you thought of using a service where you can email faxes to a fax number? Scan your fax, attach to an email and send over the net to the fax machine? I don't know how well these services work but might be a thought?

I typed email to fax into google and got this..

http://home.efax.com/s/r/efax_green_LP?VID=33675&gclid=CK7Ug8iDxZoCFRJhnAoduR7wtA

 

I switched over to a VOIP provider a few week back and love the service and savings (voice calls are clear as a bell and it's 1/3rd the price of a landline). Having said that, I am having a problem sending/receiving faxes: I can usually send a one or two page fax, but anything larger will typically fail. And I cannot receive faxes...period. I have a 2/3 year old HP 5110 all-in-one Officejet that has worked flawlessly prior to switching over the VOIP.

1. Checked FAX Setup...there are no options that would prevent the fax machine from sending/receiving faxes.

2. Ran a VOIP bandwidth/quality check at www.testmyvoip.com - my connection is pretty good: as low as 3.9 (better than a good cell phone call) and 4.4 (like calling next door).

3. Dishnetwork receivers dial-out...I've check my bill and ordered a PPV movie via the receiver.

4. Fax picks up at ring 3, voicemail was setup to answer after ring 6.

5. My landline won't be permanently disconnected until 8 May. I hooked it back up and the fax works without failure.
I just recently updated from Voip Sip SDK - The easiest way to add dial and receive phone calls features to your applications they provide really good service.
http://www.voipsipsdk.com