Connection getting closed after some time [1]

I am using XManager 2.0 to connect to AIX machine.After 3-4 hrs, the connection gets closed.Do I need to set any parameter to get rid of this issues.Any input on this will be very helpful.

I think you have time out setup in firewall or server. Timeout will abruptly disconnect you if your connection is left idle for a certain period.

If you are using SSH, try using the keep alive option in Xstart. (Xstart > Select SSH > Setup...)