Knowlege base

Enable G.729 signaling for Stonefax

Article ID: 549
Last updated: 29 Jul, 2021

Applies to:

All IAS versions.


Enable G.729A codec capability for Digital Fax.


In order to enable G.729A signaling for Digital Fax please proceed as follow:

1) Open the file <StonevoiceAS>\Apps\StoneFax\Server\System\StoneFax.ini

2) Add one of the following parameters to the section [Impostazioni]:

    a) To enable only G.729A as audio codec:

     T38_LOG_OPTIONS= --sip-audio G.729  

    b) To enable both G.711 and G.729A as audio codecs:

     T38_LOG_OPTIONS= --sip-audio G.711-Alaw-64k --sip-audio G.711-ulaw-64k --sip-audio G.729

The row should appear similar to the following:

T38_LOG_OPTIONS= --sip-audio G.711-Alaw-64k --sip-audio G.711-ulaw-64k --sip-audio G.729 

3) Save and close the StoneFax.ini file

4) Stop and Start the Digital Fax service in the page Fax Server |  Manage Service [Stop/Start]

5) Make a test

IMPORTANT NOTE: G.729 cannot be used to send/receive faxes in voice passthrough mode. It can be enabled in certain scenarios only to permit the initial call hadshake with PBX or voice gateways. In facts, a voice call established in G.729 codec should immediately switch to a T.38 session to permit the proper fax transmission/reception.

Article ID: 549
Last updated: 29 Jul, 2021
Revision: 11
Views: 1025
Print Export to PDF Subscribe Share
This article was:  
Prev   Next
Unable to receive faxes on Windows Server 2012 R2 with fxssvc...     How to modify mail notification templates for admin and users in...