Messages are converted between WebSphere MQ format and service integration format as they flow between the two systems.
In general, you do not need to be aware of conversion between message formats to exchange JMS messages between service integration and WebSphere MQ. However, you might need to learn about message conversion if your JMS applications do not behave as expected or if your service integration configuration includes JMS programs or mediations that process messages to or from non-JMS WebSphere MQ programs.
If your service integration applications exchange MapMessage objects with WebSphere MQ applications, you might need to specify a non-default map message encoding format. For more information, see Setting the WebSphere MQ encoding format for JMS Map entries.