Patent ID: 8631152

Claim:
A system for transmitting and receiving a data packet, the system comprising: a receiving apparatus that is adapted to receive a transmitted data packet, the receiving apparatus including a receive buffer that stores a data packet therein, and a size specifying information transmitting unit that transmits to a transmitting apparatus, when a data packet stored in the receive buffer is read, size specifying information which does not correspond with the size of the data packet read, the data packet being read out in an order that the receiving apparatus receives the data packet; and a transmitting apparatus that is adapted to transmit a data packet to the receiving apparatus, the transmitting apparatus including a transmit buffer that stores a data packet therein, a credit storage that stores a credit count being a value corresponding with a total size of all data packets currently stored in a capacity of the receive buffer, and stores, when a data packet is transmitted to the receiving apparatus, a credit element having a value that corresponds to the size of the data packet, a credit adding unit that increments the credit count by a value corresponding with the size of a data packet transmitted when the transmitting apparatus transmits the data packet, a credit subtracting unit that decrements the credit count by a value corresponding to an oldest credit element stored in the credit storage and deletes the oldest credit element when the receiving apparatus transmits the size specifying information to the transmitting apparatus, and a transmission controlling unit that controls permission and suspension of transmission of a data packet to be transmitted from the transmitting apparatus based on a value of the credit count stored in the credit storage.