A method includes determining a state of operational devices in a second group coupled with a second router onboard a second vehicular unit of a vehicle consist, registering an operational device in the second group based on the determined state, and transmitting a data message from an operational device in a first group of operational devices to the second router via a first router and a communication pathway of the vehicle consist. The first group is coupled with the first router onboard a first vehicular unit. The operational devices in the first and second groups perform functions of the respective first vehicular unit and second vehicular unit. The first and second routers are connected with each other by the communication pathway. The method also includes communicating the data message to the at least one of the operational devices in the second group that are registered with the second router.