f you experience OWA when receiving calls on your X-ten softphone it may be due to a problem in codec negotiation. X-ten by default chooses the best sounding codec (G711), even if other codecs are provided to it in the initial INVITE. It also offers other supported codecs in its 200 OK response, while latching onto G711. Since Polycoms prefer G729, they latch on to G729 based on the received 200 OK response, thus creating OWA.
To fix this, open your softphone and dial ***7469, then put honor in the search filter. Double click the value to change it, enter 1 to enable the setting, then click the OK button. Restart the softphone and re-test. Contact Partner Support if you continue to experience OWA issues after making the changes.