Hello Lloyd, LW> HTTP and BEEP aren't transport protocols. LW> session and transfer protocols, perhaps. LW> Since they both run over TCP, they're both completely wrong for RPC. LW> XMLRPC - it's not XML, and it's not RPC. You are absolutely right concerning HTTP and BEEP, but I suppose that choice of mentioned protocols as a "transport" layer for SOAP and XMLRPC can be explained by the fact that it simplifies PROXY access. It is very important, but it should not break networking principles. Thus BEEP reintroduces such TCP features as port multiplexing and sliding window flow control. Besides the modern applications require high level RPC mechanisms giving facilities for complex structured data transmission (documents, objects, etc.). Best regards, Timur mailto:Timur@niist.ntu-kpi.kiev.ua