Solution : https://service.sap.com/sap/support/notes/632483 (SAP Service marketplace login required)
Key words : 
sql net v2 / net8 / oracle net, sql error '6401'oci-call 'olog' failed, invalid driver designator calling tp, sql net v1 connection, svrmgr> connect sapr3/sapr3@, syntactically incorrect character strings, world = # production system<tns_alias>, sql net v1, invalid driver designator 4, sql-net v1connecting
Related Notes : 
       
| 602843 | Environment settings for R/3/Oracle on UNIX | 
| 556232 | Environment settings for R/3/Oracle on Windows | 
| 445038 | Problems when accessing Net8 configuration files |