Solution : https://service.sap.com/sap/support/notes/61041 (SAP Service marketplace login required)
Key words : 
/usr/sap/<sapsid>/sys/exe/run/install/netv2if netv2, /<kernel cd>/unix/<operating system>/install/netv2 firstly, directory /<kernel cd>/unix/<operating system>/install, usr/sap/<sapsid>/sys/profile/default, thedirectory          /<kernel cd>/unix/common/install, symbolic link    /usr/sap/trans/listener, file /usr/sap/trans/bin/tpparam, additional key words sql-net, parameter    dbs/ora/tnsname = <sapsid>, directory /usr/sap/trans    tnsnames
Related Notes : 
       
| 142255 | NT/ORACLE: Background input processing terminates | 
| 84612 | Database Release Oracle 7.3.3.3.0 is not supported | 
| 80274 | Additional info: ORACLE upgrade to 7.3.3: UNIX | 
| 72638 | Performance problems with SQL*Net | 
| 64164 | |
| 34479 | Collective note for problems with SQL-Net V2 ORACLE |