On the SBC main screen, go to Configuration > Profile Management > Category: Media Profiles > Codec Entry > Silence Suppression or
All > Profiles > Media > Codec Entry > Silence Suppression
The Silence Suppression window opens. Select a Codec Entry from the drop-down list to view and edit its silence suppression mode. Be aware that not all codec entries are based on codecs that support silence suppression.
Use the following table to edit silence suppression mode and then click Save.