Hi all, I'm not a very experienced J2EE developer. Recently, I'm trying to write an application which is divided into 3 tiers: * business logic level (running on a J2EE server) consists of EJB components. * orchestration level (running on a J2EE server) which will accept requests from client applications (not web browsers) and talk to business logic level components to achieve certain tasks * client level will run heavy client applications which will talk to orchestration level across internet connections. My question is: what communication method/protocol will be suitable for the communications between these 3 tiers. The options are: * RMI-IIOP * XML-RPC * SOAP * Other :) P.S. Transfer of binary data is also required Could some one please give me some advices of which communication methods shall I use? Performance is the priority consideration. Please help. Thanks!! Joe

XML-RPC: I think, it is so simple for you. RMI-IIOP: This protocol has a good performance. But you will have problems with orchestration products and with interoperability. (theoretically no :) ). SOAP: With this way you will lose in performance but you will gain in orchestration products and with interoperability. Amazon is a large system, and they use soap.