submitShortMessage IO error about jsmpp HOT 1 CLOSED

It has 2 session the, the sender and receiver.
The receiver still accept the messages without disconnected even the SMPP 
Server restarted. You should question 
on the SMPP Server then. How can plain socket still connected while SMPP Server 
restarted, so it might never 
closed. Does the SMPP Server process really dead? or the connection never 
really closed?

The sender has normal behavior.

Please inform me for further report of your programs.