TNS-12535: TNS:operation timed out

 Hello,

I have  2 node RAC database(11.2.0.3) running on OEL6.4 and unfortunately i am not able to connect to the database from remote windows client machine(win-7-64 bit)

Getting TNS-12535: TNS:operation timed out

I am able to telnet on pubic ips but unable to telnet on vip and scan ips.

Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = SCAN-EPPM-DB.aje.ae)(PORT = 1521)) (CONNECT_DATA = (SERVEREDICATED) (SERVICE_NAME = AJCEPPM)))

hanging and then TNS-12535: TNS:operation timed out

#SQLNET.AUTHENTICATION_SERVICES= (NTS)

##i tried above and below option of SQLNET.AUTHENTICATION_SERVICES but no luck

SQLNET.AUTHENTICATION_SERVICES= (NONE)

NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)