Oddity With FFA

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Asterisk Users 6 Comments

Hi all,

For the most part, we are finding that Fax for Asterisk works pretty well. However, we have seen some wierdness that we’d like to try to fix.

Once in a while, we will get a partial result report for a given fax but when we look at the actual .tiff image, it looks to be complete. This is causing our users to not get a positive acknowledgement when they send the fax.

Is there anything we can do to mitigate this?

Mike.

6 thoughts on - Oddity With FFA

  • How do you know the FAX is complete? If a page was received, the sending machine said more pages were to follow, and then it dropped the call, is that a complete FAX?

    Steve

  • One of my customers had this problem. The cause turned out to be the other side (one particular remote station).

    In addition to res_fax, I also installed the Hylafax/iaxmodem combo. Hylafax has the advantage of giving nice logs about the signaling. This way it was easy to see what was going on, but I
    have forgotten the details meanwhile.

    jg

  • Steve,

    I BELIEVE the fax is complete because the fax image is a form that appears to only be a single page.

    But, since FFA isn’t providing acknowledgement, the sending fax machine is resending the document multiple times!

    Mike.

  • Hi Mike,

    If the sending machine keeps trying it might be the call has been hung up by asterisk before its own acknowledgement message has finished being sent. There have been bugs like this in the past, and people can be pretty casual about making changes which hang up aggressively. A FAX
    system should really wait for the final DCN message before disconnecting, to ensure both sides have seen what they need. Spandsp does that, but I am not sure about FFA.

    Regards, Steve

  • Steve,

    I appreciate you elaborating on my problem. I don’t suppose this is as easy as putting a wait(3) in my dial plan before hangup…..? (Didn’t think so.)

    Aside from checking (and hoping) for a newer version of FFA that fixes this issue, I guess there’s not much I can do, then.

    Thanks again.

    Mike.