Solution : https://service.sap.com/sap/support/notes/984721 (SAP Service marketplace login required)
Key words : 
terms icm wakeup nipsendto reason, bc-cst-ni component, dev_icm/dev_webdisp trace file, sap web dispatcher, resource temporarily unavailable, network error occurs, nipsendto rc=-1 [nixxi_r_mt, nipsendto failed, trace file, error trace
Related Notes : 
       
| 991211 | CST Patch Collection 42 2006 | 
| 634262 | Note on the preclarification of SAP Web dispatcher messages | 
| 634006 | Note on the preclarification of ICM messages |