Equisys Technical Notes

Technical guidance, explanations and fixes for our products


FIX: Zetafax Server fails to send faxes with Error: Parameter length error (18 internal SIP)



ID: ZTN1866

This Zetafax technical note applies to:

  • Zetafax 2011


This error only applies to systems using standard FOIP.

The Zetafax Server fails to send faxes and displays the following error in the server log:

“Error: Parameter length error (18 internal SIP)”

Once this error has occurred, all subsequent sent faxes will fail with the same error until the Zetafax Server is restarted.


This problem is caused because the Zetafax Server loses the configured gateway IP address and port.  Once this has happened it is no longer able to communicate with your gateway and so all faxes then fail to send.


This problem can be resolved by installing a patch which is available here.

This patch is available using the password provided in your Software Assurance newsletter. For more details on gaining access to this password email: support@equisys.com


This behaviour was fixed in a patch of Zetafax.

Last updated: 21/09/2011 (JW/MW)

Keywords: Zetafax Server Error FOIP SIP


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