Road side machine, vehicle-mounted device, communication system and communication method

The roadside device has: a communication unit that receives data transmitted from the vehicle-mounted device and transfers the data to the server; and a control unit that, when an upload restart request for the data is received from the in-vehicle device during the transfer of the data to the server, retains the transfer of the upload restart request to the server. 路侧机具有：通信部，接收从车载器发送的数据，并转送给服务器；以及控制部，在数据向服务器的转送中，在从车载器接收到数据的上传再次开始请求的情况下，保留向服务器的上传再次开始请求的转送。