Application is responsible for the implementation of route calculation.
Route handler has a signature of OrderGatewayGetRouteHandler. It takes a message from buy side (New Order, Cancel or Replace) and returns an integer equals the FIXSession.EngineSessionID of the FIX session the message is going to be routed to.
Route handler should be set to FIXOrderGateway.RouteHandler property. Note it is a property, not an event.
User can also specify Visual Lambda rules on top of the route handler. The Visual Lambda routing rules can be statically defined with QWFIX Enterprise Manager or dynamically defined during run-time.
Visual Lambda rules has higher precedence so that user can modify routing rules later on without modifying program.