It's my understanding that the JMSActivation will be used for an MDB but if you create a connection directly (from inside your Ejb for instance) using the managed connection factory then (if it can't find an appropriate cached one) then a new JMSManagedConnection will be created and JMSManagedConnection::setup() wil be called. AFAICT This will always end up creating an XAConnection (even for JBoss MQ) if the default JMSProviderAdapter is used, since the default JMSProviderAdapter shipped with AS4.x always looks up using /XAConnectionFactory. So I don't see how separating out Connection and XAConnection is going to help. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4039925#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...