Solution : https://service.sap.com/sap/support/notes/1173152 (SAP Service marketplace login required)
Key words :
<port>/dir/rep/cmstransport/ext, <port>/rep/rep/cmstransport/ext, symptom xi test connect, method=transport&innermethod=getserverversionorhttp, method=transport&innermethod=getserverversion, terms cts+ reason, prerequisites programming error, error message, communication parameters, work correctly