By default, messages are routed to the application identified in the destination_addr field of the submitted message. Messages are only routed between application identifiers within the same messaging domain. The domain is specified in the system_type parameter when the application connects and binds to Message Hub.

For example, if the destination_addr in a submit_sm from application #A is set to "1111222233330000", then the message contained in that submit_sm will be sent to the application that connected and bound to Message Hub with a system_id that is the application identifier "1111222233330000".

Routing rules can be defined to route messages to destination applications other than specified in a message's destination_addr field. Broadcasting a single message to multiple applications is also possible.