R/3 to R/3 IDOC Sending with HTTP

Hello everybody,

I'm trying to send an Idoc from one R/3 System to another, I'm trying to use the function module IDOCS_OUTPUT_VIA_XML_HTTP and it requires an XML HTTP port in we21, now I'm trying to create an HTTP RFC connection but I'm lost with the path refix parameter, can anyone tell me what should be in that field?

Regards,

Julio