Patent ID: 8700866

Claim:
A data transfer apparatus comprising: a first port and a second port that communicate data; a memory unit that stores the data; a securing unit that secures, when a first time period starting from transmission of data up to reception of a response to transmitted data at the first port is longer than a second time period starting from transmission of data up to reception of a response to transmitted data at the second port, a first memory space that is used in data transfer in the first port so as for the first memory space to have a larger size than a size of a second memory space used in data transfer in the second port, the securing unit securing a size of the first memory space and a size of the second memory space based on a ratio of duration of the first time period and duration of the second time period; and a dividing unit that divides each of the first memory space and the second memory space into a reception buffer space, a transmission buffer space, and a retransmission buffer space, the retransmission buffer space storing a packet to be retransmitted responsive to receiving a negative acknowledgment (NAK).