The existing test, the Simple Type Test is centred around the AMQP 1.0 simple types, and is designed to send AMQP types between clients to check interoperability.
However, in the world of JMS, this approach is not ideal, as there is no direct mapping between JMS message types and AMQP simple types. The idea is to add another test, which is centred around the five basic JMS message types rather than the AMQP types. This will allow these message types to drive the test values rather than the AMQP types, and will provide a more efficient mechanism for testing JMS interoperability between clients. While it may be possible to test between non-JMS clients, it makes sense that one or more JMS clients (such as qpid-jms) always be one of the two test clients.