Abstract: An in-vehicle system comprising a gateway between multiple networks is disclosed. One of the networks specifies that when a source apparatus connected to the one of the networks sends a request message to a destination apparatus connected to another one of the networks, the source apparatus should time-out if the source apparatus does not receive a response message within a specified time after sending the request message. Upon receipt of the request message, the gateway relays the request message to the destination apparatus and sends a wait request code to the source apparatus to instruct the source apparatus to wait by extending the specified time.