Setting up Fax on LaserJet M681 MFP

[JoshAhart]

Limited knowledge of faxing but this is what I know:

Trying to setup fax for a client, they purchased this brand new LaserJet M681, they are using this to replace a Kyocera Ecosys M6536 MFP.  The faxing worked just fine on the Kyocera machine.  

They have VOIP through GoToConnect, they currently have a Cisco SPA122 conversion device, which to my knowledge, should convert the VOIP line to analog, but due to my limited fax knowledge I wanted to try and confirm if that was correct or not.  

Because if that is the case I was wondering if turning error correction mode off was still a requirement even though the VOIP line should be converting to Analog, or if error correction mode is the reason it is failing.  

For reference the error I get when the fax fails 90 percent of the time is No Carrier.  I have been able to make the fax call my cell phone, and have even successfully sent a fax a couple of times, but most of the time it fails.  

If anyone has any insight it would be greatly appreciated.  

[Repairatrooper]

Even with line conversion devices, the timing on voip is different than an analogue line and can cause issues. There might be a delay in the dialtone beign recognized which means you might want to check the box in setup that says "wait for dialtone" and yes errror correction likely will need to be disabled.

[JoshAhart]

None of the settings on the printer itself are working, still keep getting no carrier error.  Been in contact with the company who provides the VOIP line and they are adamant that the Cisco ATA is working, so the fax should be working.  I'm all out of ideas, only one I have left is that, the Cisco ATA is providing the phone line to the printer, but the ethernet line is coming from elsewhere.  I could only connect to the web interface of the ATA by plugging my laptop directly into it, maybe the printer also needs to receive it's ethernet from the Cisco ATA, any thoughts on this?  The old Kyocera printer has 2 phone ports as well, while this new one has only one, and the only way I can setup is via internal modem, not sure of the correlation of that but I am trying to explore all possible issues.  Let me know if anything doesn't make sense and I can try and explain it better.