Dear all I have a Asterisk server (version 1.0.7) running with a TE110P card on a 3Ghz P4 machine (running nothing else but asterisk) So far so good. Today I was trying to receive faxes using spandsp fax client. I used spandsp v0.0.2pre18 (which compiled against libtiff 3.5.7) It compiled fine, installed fine, run fine. But when sending a fax (from a Brother fax machine) the image received is always corrupted: lines are missing, segments of the faxed page aren't there etc... I could attach an example (it's 40KB) but I wasn't sure that the rules of the asterisk-user DL forbid attachment. In your experience, is this something to expect or should the fax received be complete? Is there any other fax package out there to receive a fax and send it through email? Thank you for your help Jean-Yves --- Jean-Yves Avenard Hydrix Pty Ltd - Embedding the net www.hydrix.com | fax +61 3 95722686 | office +61 3 8573 5299 | direct +61 3 8573 5200 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20050513/70260a51/attachment.htm
> But when sending a fax (from a Brother fax machine) the image received isalways corrupted: lines are missing, > segments of the faxed page aren't there etc... Run ZTTEST in /usr/src/zaptel. Your output should be 99.98XXX% or higher. If it isn't the corruption is most likely because of IRQ misses by the card. Run it for a couple of minutes. Your "worst" should be 99.98XXX%. Subtle timing errors and IRQ misses that are not audible will screw up a fax. Also timing errors on your PRI are another cause. You have to ensure your card is recieving timing correctly by the telco. and your span is set up appropriately to reflect that. Ensure the usual things are true: turn off any service you do not absolutely need, disable Hyperthreading in the CPU, turn off any device that you do not need, such as sound card, USB interface, serial ports, parallell ports, everything you can think of is off. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20050513/8daea177/attachment.htm
u said: I will try upgrading to a newer kernel (I'm using Fedora Core 2 with 2.6.8 kernel), turn off hyper-threading and see if it makes any difference... i said: wierd. Im running fc2 2.6.8 smp no problems. Could be timing slips on your PRI, happened to me until I looked hard at the PRI good luck let me know
Peter Svensson wrote:>On Mon, 16 May 2005, Steve Underwood wrote: > > > >>>It is possible, though complicated, to synchronize the 2Mbit clocks on two >>>unrelated cards by measuring the accumulated phase shift (difference in >>>interrupt rate) over time and compensating, thus implementing a PLL in >>>software. Digium has not shown any intereset in such a solution. It is not >>>clear if the internal hardware clock generator can be fine tuned enough to >>>implement this. >>> >>> >>> >>> >>How can that work? You can measure the error, but you have no ability to >>tweak the clock from software. Two cards could only be synced by hardware. >> >> > >In most hardware the clock you use is not provided by a crystal. Rather >the crystal provides a reference for a pll. The conversion factor between >the crystan and the derived clock is usually tunable. > >Nope. Its always a crystal. Its either a pullable crystal in a VCXO, or its pulse-stuffed. It is required by the ITU specs to settle within 50ppm of the correct frequency when there is no signal driving its PLL, but many are out of spec. This is neither here nor there for the matter under discussion.>Whether the actual clock on the Digium cards is tunable enough I do not >know. There are quite a few references to programming the clock in the >source. > >Have you ever seen a framer where software can tune it? Its a hardware thing. Regards, Steve
Hi Steve We have been struggling for some time to get spandsp working properly on our asterisk system. We are using a TE410P card with a single E1 from our PTT (Zaptel primary clock source) and another E1 to a NEC PBX. The NEC PBX in turn has an E1 connection to a Tenovis I55 PBX, which then has Basic Rate connections to a Cycos MRS Fax server. We never experience problems with the Cycos Fax server (which uses an Eicon Diva card). We also do not experience problems on the 7 or 8 fax machines connected to our NEC and Tenovis PBXs (nor do we hear any 'clicks' on voice calls). Therefore we conclude that we do not have any 'timing slips' or suchlike with our setup. However, receiving faxes on the Asterisk with spandsp presents us with a problem - if we send a fax from a particular fax machine (old MITA machine), spandsp invariably does not receive the whole fax, cutting it at some unpredictable point. This particular fax machine is in daily use and works fine to any other fax machine. My knowledge of fax principles being quite limited, it seems to me that spandsp communicates perfectly with the transmitting fax machine up to a point, whereupon it fails to react to the transmitting machine's instructions to advance to the next line scanned. This results in subsequent lines being superimposed upon each other, producing a dark horizontal line somewhere within the page (usually less than halfway). I'm inclined to believe that this must be a small problem which can be catered for in spandsp's code, and make myself available to send you test faxes if you would like to verify this problem. Best regards Les Caroto Logitel Telecom Johannesburg South Africa -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.323 / Virus Database: 267.7.7/20 - Release Date: 2005/06/16 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20050618/764072c8/attachment.htm