Dialogic's JCT cards are not setup to have CSP (continuous speech processing) by default. You will need to open up Dialogic's DCM (Dialogic Configuration Manager) and manually configure the JCT cards if you want barge-in active.
First find and select the JCT card from the list

Make sure the Dialogic Service is not running (press the Stop button if necessary).
Make sure the TeleVantage server service is not running as well.
Open up the device and go to the 'Misc' tab.
Make sure the Parameter 'CSPExtraTimeSlot' is 'ON'.
Change the Firmware file from default to the one with "CSP" in the name. (The exact name varies.)
Hit the 'OK' button and then use 'Start' button to restart the Dialogic Service.

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