Nenad Radosavljevic
2005-May-15 12:08 UTC
[Asterisk-Users] Re: SpanDSP TXFax and multipage faxes problems (aditional info)
Thanks for the information Lee ! Still, something is still strange to me, since this two Panasonic Fax machines are receiving at least 20 multi-paged faxes a day (they are in same office as both Asterisk boxes, and me :) ). Beside that, POTS lines in those two faxes are from same PSTN switch as line in X100P in one of Asterisk boxes, and the ISDN PRI lines in other Asterisk box is from same PSTN switch also. I there is probelm in audio path, then how is it possible that first page is crystal clear always ? I really don't understad how the line condition can affect sending from X100P to a Panasonic faxes and don't affect sending to PRI on another Asterisk. Even more strange is that when I send from Asterisk with a PRI, Panasonics don't get more that one page of fax and Asterisk with the X100P gets it all ?!? I don't want to jump to conclusions, but this seems to me that is more like that txfax has some "issue" with Panasonic during the hanshaking phase in between pages ??? Regards, Nenad> Nenad Radosavljevic wrote: > >> Hi everyone ! >> >> I have some aditional info on problem with TXFax and sending >> multi-page TIFFs. >> >> I have made 6 different multi-page TIFFs (Group3 1D with fillbits EOL >> aligned - 3 pages one TIFF in lowres and one in hires, Group3 2D -3 >> pages againg in both resolutions , and Group 4 - 3pages in both >> resolutions) > > > You can't send G4 (MMR) images with spandsp yet. MMR support requires > ECM support. So if it actually transmits, then txfax is probably > converting the image on the fly. > >> , and then tried to send them to Panasonic KX-F1100, Panasonic KX-F500 >> and SpanDSP RXFax on different Asterisk server then sending one, over >> POTS. >> >> Results are: >> >> 1. KX-F1100 always gets first page and if fax is in HIRES it delivers >> empty second page and hangs up (report say communication error). >> >> 2. KX-F500 gets always gets only first couple of centimeters of first >> page and hangs up (again communication error). > > > These sound like the receivers are detecting carrier losses when they > shouldn't. Meaning that the communication path is not clean. Somewhere > between sender and receiver there is significant audio loss or audio > corruption occurring. But that is not happening between your two > Asterisk boxes. > > Lee.
Lee Howard
2005-May-15 22:13 UTC
[Asterisk-Users] Re: SpanDSP TXFax and multipage faxes problems (aditional info)
Nenad, You said that the second page was terminating at some point after the start of the fax image. There is no "handshaking" going on after page image data starts. Because txfax does not currently support ECM the only reason why a page of image data would terminate prematurely is because the receiver detected a carrier drop when there wasn't one. So, I really can't go into figuring out why things are happening the way that they are, I'll leave the hypothesizing up to you, but as I have experience programming fax receivers, I can tell you that the receiver will only truncate a non-ECM page when a premature carrier drop is detected. Lee. On Sun, 15 May 2005, Nenad Radosavljevic wrote:> Thanks for the information Lee ! > > Still, something is still strange to me, since this two Panasonic Fax > machines are receiving at least 20 multi-paged faxes a day (they are in same > office as both Asterisk boxes, and me :) ). Beside that, POTS lines in those > two faxes > are from same PSTN switch as line in X100P in one of Asterisk boxes, and the > ISDN PRI lines in other Asterisk box is from same PSTN switch also. > > I there is probelm in audio path, then how is it possible that first page is > crystal clear always ? > > I really don't understad how the line condition can affect sending from > X100P to a > Panasonic faxes and don't affect sending to PRI on another Asterisk. > > Even more strange is that when I send from Asterisk with a PRI, Panasonics > don't > get more that one page of fax and Asterisk with the X100P gets it all ?!? > > I don't want to jump to conclusions, but this seems to me that is more like > that txfax has > some "issue" with Panasonic during the hanshaking phase in between pages ??? > > Regards, > Nenad