Equisys technical notes

Technical guidance, explanations and fixes for our products

FIX: Outbound faxes fail to a small subset of recipients



This Zetadocs technical note applies to:

  • Version 2014 or 17.0 of Zetafax
  • Dialogic devices TR1034 & SR140


Outbound faxes to a small subset of numbers will suddenly fail. Faxes will fail each attempt, and the reporting error “Call Busy” or “error sending end-of-document” in the Zetafax server logs. Investigation will reveal that the number is not busy, and faxes can be sent to recipient manually via fax machine.


Changes made in later versions of some call managers may require advanced tuning to ensure reliable fax connections. The recipient may have recently updated their call manager systems.


Equisys has issued an update to the fax board drivers that addresses many of these changes. We recommend that clients experiencing this issue download and install the new Brooktrout 6.7.5 SDK package. A technote describing this update is located here.

Note that in some cases, advanced configuration options within the new SDK may require adjustments. If the update does not fully resolve the issue, please contact Equisys Technical Support.

Last updated: 17th November 2016 (KD/NT) 

Keywords: Brooktrout DEVBTB

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