Fax error codes (sending)

Unfortunately, there are know issues and limitation with all IP (internet) based fax services.  As such, these services are always offered as a best effort.

Faxing over the internet has technology limitations that are industry-wide.  VoIP providers send faxes over the internet using a standard called T.38. Although the standard offers better reliability, the standard is still open to interpretation by fax machine vendors and therefore cannot be a guaranteed transmission on an end-to-end bases.

Below are the most common error codes you may receive.:
                                                                                                                                                              
 Connection failed  There was no receiver on the other end of the call to connect to. 
 Document generation error.  There was an error while generating the document. This could be due to the file being deleted before sending. 
 Failed to train with any of the compatible modems  A remote fax machine was detected, but the sending and receiving modems could not establish communication. 
 Fax transmission not established  We could not detect a remote fax machine. This could be due to there being no fax machine on the receiving end, or a lack of call clarity. 
 Log entry lost  The call started, but the log entry for the call was lost / incomplete. In practice, this should be rare and may indicate a system problem. 
 No response after sending a page  The remote fax machine did not acknowledge that a page of the fax was received. Depending on the remote machine's behaviour, it may have still printed the page and any preceding pages. 
 Received no response to DCS or TCF  The fax service could not successfully determine the remote machine's fax capabilities. 
 The call dropped prematurely  The call dropped due to a non-fax transmission error. It is likely that the receiver hung up. 
 The HDLC carrier did not stop in a timely manner  The fax service initiated a fax transmission with the receiver, but there was a synchronization (timing) error that could not be resolved. 
 Timed out waiting for initial communication  A call was established with the receiver and the bulk fax service attempted to establish a fax session, but there was no fax response from the receiver. This could be due to there being no fax machine on the receiving end, or a lack of call clarity. 
 Timed out waiting for the first message  A call was established with the receiver and the fax service attempted to establish a fax session, but there was no fax response from the receiver. This could be due to there being no fax machine on the receiving end, or a lack of call clarity. 
 Unexpected DCN while waiting for DCS or DIS  The remote fax machine unexpectedly sent a disconnect message when the fax service asked for the remote fax machine's fax capabilities. 
 Received bad response to DCS or training  An unexpected message was received when the bulk fax service asked for the remote fax machine's fax capabilities. 
 Invalid response after sending a page  An unexpected message was received after successfully sending a page. Depending on the remote machine's behaviour, it may have still printed the sent page and any preceding pages. 
 Disconnected after permitted retries  The fax service attempted to send the same message multiple times unsuccessfully. This may be due to a call clarity issue. 
 Far end cannot receive at the resolution of the image  The remote fax machine does not support receiving faxes sent at the resolution that our service sends at. 
 Received a DCN from remote after sending a page  The remote fax machine responded with a disconnect message after a page was sent successfully. Depending on the remote machine's behaviour, it may have still printed the sent page and any preceding pages.  
 Unexpected message received  The fax service received a message that it did not expect given the current context. 
 Received other than DIS while waiting for DIS  The fax service expected to receive the remote fax machine's fax capabilities, but received an unexpected message instead. 
 Unexpected DCN after EOM or MPS sequence  The remote fax machine disconnected unexpectedly after receiving a page of a multi-page fax. Depending on the remote machine's behaviour, it may have still printed the sent page and any preceding pages.  
 Document loading error.  The fax service attempted to generate the message to send, but a document was missing.  
 Invalid ECM response received from receiver  The fax service received an invalid error correction message from the remote fax machine. 
 Unexpected DCN after RR/RNR sequence   The remote fax machine disconnected unexpectedly after indicating that it was not ready to initiate a fax session.