Messaging in J2EE 1.4

Today I had a look through developerworks at IBM's, and stumbled across an article called 'Get the message: Messaging in J2EE 1.4 from ibm.com .

The paper says that the J2EE 1.4 introduces changes to the way an application server uses JMS. In particular, you can only have one active (not-closed) Session per connection at any one time. This could be a bit confusing at first but that's part of the EJB spec. A call to createSession returns always the same session. In J2EE 1.4 this has moved from the app server to a JCA 1.5 resource provider. So for outbound messaging it has only 1 session per connection, so in fact the connection will be the entity for transactional control like it is the case for a database connection.