Solution : https://service.sap.com/sap/support/notes/64015 (SAP Service marketplace login required)
Key words : 
terms testtoollgtstmessage serverlogon groupsload distributionsm51smlgrzlliclassweighted round robin procedure reason, select sap netweaver -> solution lifecycle management -> system management -> tools, 8] [sapdp01] [3201] [dia vb enq btc spo ][oss006_o01_01] [oss006] [147, requestthe weighted round robin procedure, /saphelp_nw04/helpdata/en/40/c235c15ab7468bb31599cc759179ef/frameset, message server> rdisp/msserv = sapms<sid>, message server /logongroup test tool, 8] [3201] [640] [true] [oss001_o01_01]  group-id = 2  time, reachable application servers-------------------------------------[oss001_o01_01] [oss001] [147, 14] [sapdp01] [3201] [dia ][oss005_o01_01] [oss005] [147
Related Notes : 
       
| 1112104 | Weighted round robin procedure | 
| 650729 | Description of the msclients test program | 
| 609096 | CST Patch Collection 15 2003 | 
| 593058 | New RFC load balancing procedure | 
| 545136 | FAQ: Test tools for RFC connections | 
| 540379 | Ports and services used by SAP | 
| 71108 | saplogon for UNIX SAPguis | 
| 64016 | Using the SAP Gateway monitor GWMON | 
| 63342 | List: NI error codes | 
| 42692 | Test tool for RFC links: sapinfo | 
| 42074 | Using the R/3 dispatcher monitor 'dpmon' | 
| 34998 | Checking on OS level whether R/3 is running | 
| 34376 | Error TN000 "Failed to connect to SAP OSS server" | 
| 26317 | Set up for LOGON group for autom. load balancing | 
| 24177 | OSS1: Message S1452: Connection to Message Server |