atcomsystems.ca/forum Forums TDM Business Telephone Systems Comdial Telephones & Systems Faxing Unsustainable connection (1120) error

Our company sends roughly 13k faxes a day, we are a medical transcription service. We use Faxback’s “Netsatisfaxtion” software to send these faxes. Of the 300 plus clients we have we have two who are reporting problems receiving our faxed items.

The two problems being reported is they get only the cover sheet of a fax we send or they get a cover sheet and some, but not all, of the pages that we fax them. This is happening with multiple faxes that we send them. From our logs we can see we are logging both Normal call clearing (29200/500) and/or more frequently “Unsustainable connection (1120)” errors. From my research an Unsustainable connection (1120) error is

“No response after sending 3 end of page commands: After reaching the end of the page, an end-of-page command (MPS) is sent and an acknowledgment (MCF) is expected from the remote device. The MCF was not received. The MPS was attempted twice more. After the third failure to respond, the call was terminated. This can be caused by the remote device hanging up, line impairment such that the modem could not detect and encode the MCF command, or line noise such that our MPS was not detected by the remote device.”

We have tried switching the customer from our digital to our analog faxing server but to no avail. Other customers who have reported problems receiving our faxes that have subsequently been switched to analog no longer have problems.

The customers are using HP multi-function printers to receive the faxes. After talking with Faxback their best “guess” is line noise or loop back problems on their end, however we are having a hard time convincing them of the issue being on their end because they report that they receive faxes from other vendors / locations just fine.

I know this is probably a little vague but any ideas? Is it possible for instance that their machine is not receiving the end of page command or is not “hearing” it and hence our system is not getting the response it needs? Additionally is there any tools that can be used to log the signals coming into the customer’s fax device that can also measure signal strength in and out and what messages are being passed and acknowledged from both ends?

Since our system has roughly a 1% failure rate on 13k plus faxes a day I think my focus is to prove to the customer that the problems is their end and not ours.

Thanks for your help.

Could be a few things, are they using digital lines at the other end or pots. That's is the starting point.

Hmm, good question. I check. Thanks.

Quick question: any particular reason why this is in the Comdial category? If not, I'll move it to a more appropriate category.

Thanks!

Justin