TNS-12547: TNS:lost contact
                    
 Hi All,i m stucked with TNS : lost contact error. actutualy i have created a tns service in a 9i (9.2.0.5) database and through this service i m going to connect with an 10g(10.2.0.3) database 
                below is my service entry in tnsnames.ora file in 9i database
test = (DESCRIPTION=
                (ADDRESS=(PROTOCOL=tcp)(HOST=xx.xx.xx.xx)(PORT=1521))
                (CONNECT_DATA=(SID=testdb))
            )
but i get 
TNS-12547: TNS:lost contact error when i try tnsping test
one more thing 10g DB Box is behind the firewall. 
please help me out in this regards,
thanks
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