Oh, thank you very much. Then I must take care of the concurrency issues on the server side. I must program the SeverInvocationHandler implementation keeping in mind that multiple threads will execute the invoke() method concurrently. Is that right? Do I have to do anything else? But I think that I don't explained my original question clearly. I'll try to put it in other words: I wanted to know if the Client.invoke() method -in the client side- allows various threads to call concurrently. I've made an experiment with two threads calling Client.invoke() -the same Client instance- and the two threads do their call concurrently and happily. It's safe and good? is there any problem with this kind of use? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4031677#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...