Abstract: A training apparatus includes a server and a controller. The server is configured to send and receive messages on at least one network, to receive messages at a plurality of publisher ports, and to send messages to a plurality of subscriber ports. The controller operates the server sends a first message to a training system destination that is initially configured to receive messages on a first port. Receipt and processing of the first message causes the training system destination to subsequently receive messages on a second port. The server is configured to receive subsequent messages on the first port intended for the training system destination and to pass modified or unmodified messages to the second port. The controller determines at least one of the flow, format, content, and routing of messages received on the first port and passed to the second port based on a training scenario.