Solution : https://service.sap.com/sap/support/notes/437362 (SAP Service marketplace login required)
Key words : 
beq protocol adapter     ipc protocol adapter     tcp/ip protocol adapter     raw protocol adapter, internal limit restriction exceeded      32-bit windows error, permission denied       ibm/aix risc system/6000 error, sql error '12500'   sql error 12500 performing con, internal limit restriction exceeded      solaris error, internal limit restriction exceeded    tns-12560, protocol adapter error     tns-00510, protocol adapter error      tns-00516, operating system-related limit reached, operating system address space restrictions
Related Notes : 
       
| 583861 | UNIX: Errors due to Oracle executable | 
| 502782 | Composite SAP Note ora-4030 | 
| 378648 | Offline backup support with Oracle Fail Safe | 
| 304467 | Core dump / ORA-125XX with ReliantUnix and Oracle | 
| 180880 | ORA-12500 No Cnnct poss.8.0.5 list.to 8.0.4 DB | 
| 180430 | Installing the ORACLE client software for UNIX | 
| 142746 | ORA-12500 on Digital running two Instances | 
| 131561 | Work processes sometimes abend during database connect | 
| 98051 | Database Reconnect: Architecture and function | 
| 97953 | UNIX: Relinking of the Oracle executables | 
| 95061 | Work processes die immediately after start ORA12500 | 
| 92537 | Oracle trace is automatically active | 
| 81499 | No reconnect after offline backup | 
| 44361 | SOLARIS: Database does not start after patch import | 
| 12741 | Current versions of BR*Tools and SAPDBA |