flexfax: RE: Endless RTN -- seems to be fixed now!

["Bernd Proissl" <news@proissl.de>]

This sounds very interessting!

Against what version do i have to apply the patches?
i recently changed to 4.1beta2 because of y2k issues.

Does your fix apply to Class2.0 only?

If hylafax violates the specs, then why are there some modems which work
fine with hylafax?

Bernd

> -----Original Message-----
> From: Dmitry Bely [mailto:dbely@mail.ru]
> Sent: Friday, March 10, 2000 10:07 PM
> To: flexfax@sgi.com; hylafax-devel@hylafax.org
> Cc: news@proissl.de
> Subject: Endless RTN -- seems to be fixed now!
> 
> 
> I am glad to inform you that after a couple of days of hard work I have
> found a bug which caused infamous "endless RTN" problem. There is nothing
> special - Hylafax just violated T.4/T.class2 protocol specs :-)
> 
> To be more specific, T.4/T.class2 (Class 2.0 standard) defines the
> following format for the Phase C data (core of G3 fax protocol):
> 
> <EOL>
> <1-st encoded raw>
> <EOL>
> <2-nd encoded raw>
> <EOL>
> ...
> <last encoded raw>
> <RTC>
> <DLE><EOP>
> 
> But Hylafax generates:
> 
> <EOL>             \
> <1-st encoded raw> \
> <EOL>               \
> <2-nd encoded raw>   \ from Hylafax-generated g3 TIFF contains it
> <EOL>                /
> ...                 /
> <last encoded raw> /
> <RTC>             /     
> <RTC>             -- sendRTC()
> <DLE><EOP>
> 
> (not always -- just when no chopping happened. See the attached 
> patches for
> details).
> 
> As you can see, RTC is transmitted twice, and it may cause missing of the
> RTC/EOP and generating RTN/other transmission errors by the remote fax
> machine. Endless RTN (and possibly other unidentified errors) is here.
> 
> Well, the attached patches seems to fix that. They are still experimental
> and possibly incomplete, but they work for me (tested with Zyxel 1496E in
> Class 2.0 mode).  A Panasonic BX780 fax machine, connected to the server
> via PBX, i.e. directly, now successfully generates MCF (always responded
> with RTN before). Could you, folks, check if they work for you also.
> 
> Any comments are always welcome,
> 
> Hope to hear from you soon,
> Dmitry
> 
> P.S. I am also going to publish tsi processing bug fixes (after some
> testing). Stay tuned :-)
> 
>