Re: flexfax: HylaFAX last page problem: REMOTE HANGUP: Invalid response to MPS (code 53)

[Glenn Burkhardt <glenn@aoi.ultranet.com>]

> Hans Feringa:

> I tried to find some details of the facsimile protocol, to try and
> understand the log files better, but the references I found have
> removed the information since (like www.grayfax.com), or I can 
> not find them.

> 1) Where can I find some details about the facsimile protocol
>    (just enough to 'decode' the log files.)
> 2) How can I solve this problem.

Unfortunately, "just enough" tends to be quite a lot.  There's the TIA/EIA-592 spec for Class 2 fax control, and the CCITT T.0 - T.63 recommendations (you really only want the T.30 spec), both available from Global Engineering Documents (800-624-3974).  It's difficult to figure out what's going on without both documents, and even then it's hard.

The reponse received (Invalid response to MPS) indicates a disagreement amoung
the fax modems involved about how to proceed.  The MPS signal is described as:

>From the transmitter to the receiver.
Multipage signal - To indicate the end of a complete page of facsimile information and to return to the beginning of phase C upon receipt of a confirmation.

To debug more would require turning up the debug level to get the raw HDLC frames, and, of course, more digging into the spec.

But unless it's a bad line, the two modems just don't work together.  Does it happen for all locations you try to fax to?  You didn't mention modem type, 
destination, etc.