I'm not sure if you are trying to make a performance  comparison or choose a technology for mediation utility  but either way the options in the list do not seem to be categoriezed correctly. I do not see OSSJ falling under the same category as RMI and Corba. OSSJ is a framework for OMC applications, unless you want to use the messaging introduced in its API suite which you needed to only mention the relevant messaging mechanism such as JMS, because OSSJ is completley J2EE driven

the same comment on SOAP, cause it is not a service invokation method, it is only a high level messaging protocol and is only suitable for certain interfaces

having said that I can only make a guess on what a "mediation utility" is by looking at the term you used, I can assume it probably needs to communication with different technologies, and that would lead to Corba, and if I made the right guess then you don't need to go towards making a comparison on performance KPIs any more

since SOAP is over HTTP and using XML
it has a very low performance

currently RMI works over IIOP (CORBA protocol)
so it has same performance  with CORBA
but RMI is java specific, and you can't use it in .net,
so for .net interoperability you have to use CORBA

I don't know about other protocols, if any body can tell us about OSSJ, OPCI, SMI relation to SOAP and CORBA I would be very happy.

Take a look at mule source,

It helps with transformation of messages and you can pass messages on tcp/ip…

I’m currently investigating mule for mediation.

is this an answer to me or to jalal?

This was for jalal ......................

Actually OSS/J is not an RPC protocol like RMI or CORBA. It is rather a Java-based standard for the development of Telecommunication Management Systems. You can configure OSS/J to work over any of RMI, CORBA or Web Service.

It was really informative

does any body know about OPCI, SMI ?

is this SMI the SMI in TCP/IP and part of SNMP v2?