In a request issuing device, a specific read request unit generates a read requesting write packet including a predetermined address of a memory of a request receiving device as a write address and including, as a read address, the address of the memory in a payload. In the request receiving device, when data is written into the predetermined address of the memory, a specific read request responding unit detects reception of the read request, reads the data from the read address of the memory written into the predetermined address, and generates a read responding write packet including, in the payload, the data that has been read.