This is switch/PBX related issue, assume that you have a Avaya PBX, where the similiar issue has been reported. So, as first contact your PBX engineers/vendor for investigation. As second try to describe what type of transfer did you make in this case (SingleStep, TwoStep, Mute)?
Yes, we’ve got Avaya s8720 to do the telephony job. From the Agent side, he was trying to complete a direct transfert of an inbound interaction using an Avaya 4610 h.323 phone through the transfert hard button to a DN on witch anoter IRD application is loaded, using THE VDN/DN 5 digit number. It’s a working application, this is an unique exception.
As you suggested, I’ll proceed to look at s8720 logs and to notify the event to vendor.
EDIT In effect the interaction doesn’t seems to drop, just the originating extension isn’t been disconnected after the call transfer, even using a CTI T-Bridge application to manage the call transfert (direct).
I do not, fortunately, know Avaya and never work with it directly. So, I cannot help you with possible root cause of the issue on PBX side, maybe try to check this option "Disconnect Supervision (In/Out) if both options are configured with value “Y”- just opinion.
The issue is occurring for all DN with same type as DN in input of this topic?
I’ll check those options. No, unfortunately is a random issue not directly linked to a specific dn, but yes, it occurs only in the same conditions: same dn/extension type doing same operation (direct transfer, mechanical or through cti t-bridge application).