Interface Engine

An Interface Engine (or Message Broker) is a term used to refer to a kind of middleware application which is used to transform/ route/ clone/ translate messages.

The same interface engine can sometimes play a role of a Gateway, and in other scenarios just be a Bridge or an Intermediary. The key distinction are the business level scenarios, interactions and use cases. If an interface engine is required to perform business rules and application level responsibilities, than it's a Gateway and is listed as the Receiver in the HL7 Message. If it just needs to transform from one ITS to another, it's a Bridge. If it needs to transform from one Transport Protocol to another, it's an Intermediary.

• (Miroslav) Message Broker is yet again another interface engine that distributes the incomming messages to specified destinations according to the business rules. A Message Broker is usually required to perform a Bridge functionality. However, the question is, what role the Message Broker is playing if it needs to send an incomming HL7 message to x additional locations (e.g. as the notification message to 3rd party that a lab order took place). It needs to change a HL7 message, list itself as the sender - therefore it's the Gateway role?