Saurabh,
First of all, there is a 3.0.5 codebase available, so please make sure you are using the latest software.
The Default demonstration behaviour will Trigger a rejoin if there is 2 concequtive transmission failures in a row. This can be a poll request or a data packet failing.
A nwk rejoin (not orphan) is then attempted.
BR,
Mads