I have a problem with my current database server.
It's only happening ones or twice a month that's why
it's very difficult for me to find out what's causing the error
ORA-12535. I have already configure my listener.ora
listener_connect_timeout = 0 but this error still occurs at one time or another. sqltrace & listenr trace shows no error. So i rly don't have any clue or whatsoever of what's going on. I have also ceheck any connection time-out setting in our current network but everything seems to be ok. btw, i'm using oracle 9i.

Pls help me asap if you can as this is causing some data lost in our company's daily data upload.

regards and thanks,