Method of transferring packet data in a network by transmitting divided data packets

• US 5,903,724 A
• Filed: 09/06/1996
• Issued: 05/11/1999
• Est. Priority Date: 09/08/1995
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Masuoka, Yoshimasa, Takamoto, Yoshifumi, Kanai, Hiroki, Kitai, Katsuyoshi, Takase, Tadahiro
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Barot, Bharat
• Application Number:
  US08/708,955
• Time in Patent Office: 977 Days
• Field of Search: 395/200.01, 395/200.03, 395/200.08, 395/200.09, 395/200.11, 395/200.12, 395/200.13, 395/200.14, 395/200.17, 395/200.19, 395/200.2 , 395/311, 395/750, 395/611, 395/182.03, 395/230, 395/200.31, 395/200.54-200.62, 395/200.64, 395/200.68, 395/200.72, 395/200, 370/389, 370/440
• US Class Current: 709/200
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A communication controller at the sending computer divides data transferred from a host into sub-ACK unit packets and transfers them sequentially to a destination without waiting for the sub-ACK'"'"'s being subsequently provided by the destination. A communication controller at the receiving computer issues a sub-ACK to the sending computer for each of the sub-ACK unit packet, if the sub-ACK packet has been normally received and otherwise issues retransmission request for the sub-ACK unit packets and merges data included in the sub-ACK unit packets into the initial data, after they are normally received.

Claims

1. A method for transmitting data via a network host in a transmitting side to a receiving side, comprising the steps of:

transmitting said data packet from said host to a communication controller in said transmitting side;

dividing said data packet into a plurality of data packets by said communication controller;

transmitting said divided data packets from said communication controller to said receiving side;

transmitting, for each of said divided data packets, a sub-acknowledgement signal indicating whether said receiving side has normally received a corresponding one of the divided data packets, from said receiving side to said communication controller; and

transmitting a single acknowledgement signal, generated by said communication controller, from said communication controller to said host, after said communication controller has normally received all of said sub-acknowledgement signals.

2. A method for transmitting a data packet via a network according to claim 1, wherein said communication controller transmits said divided data packets without waiting for any of the sub-acknowledgement signals.

3. A method for transmitting a data packet via a network according to claim 1, further comprising a step of retransmitting only the divided data packets for which said communication controller has not normally received corresponding sub-acknowledgement signals.

4. A method of transmitting a data packet via a network according to claim 1, further comprising a step of determining the division size of said divided data packets based on a communication condition of said network.

5. A method of transmitting a data packet via a network according to claim 4, wherein said communication condition of said network includes at least one of a transmission time required for transmission of data over said network and the load on said network.

6. A method for transmitting a data packet via a network according to claim 1, wherein, when said network comprises two networks having different communication paths, said divided data packets are transmitted via one communication path and said sub-acknowledgement signals are transferred via the other communication path.

7. A method for transmitting data via a network, comprising the steps of:

transmitting a data packet with a destination identifier attached, from a host in a transmitting side to a communication controller in said transmitting side;

dividing said data packet into a plurality of data packets by said communication controller, in response to a division size stored in a table for said destination identifier;

transmitting said divided data packets from said communication controller to a receiving side corresponding to said destination identifier;

transmitting, for each of said divided data packets, a sub-acknowledgement signal indicating whether said receiving side has normally received a corresponding one of the divided data packets, from said receiving side to said communication controller;

transmitting a single acknowledgement signal, generated by said communication controller, from said communication controller to said host, after said communication controller has normally received all of said sub-acknowledgement signals; and

updating said division size in response to a communication condition of said network.

8. A method of transmitting data via a network according to claim 7, further comprising the steps of:

measuring a transmission time indicating the time required for transmission of said data packet from said transmitting side to said receiving side, and

reducing said division size if said transmission time exceeds a predetermined value.

9. A method of transmitting data via a network according to claim 8, further comprising the steps of:

attaching time when a packet is transmitted to each of said divided data packets, and

attaching said time to each of said sub-acknowledgement signals,

wherein the step of updating said division size comprises calculating the time required for transmission from the difference between said time attached to said sub-acknowledgement signal and the current time.

10. A method for transmitting data via a network according to claim 7, further comprising the steps of:

retransmitting only the divided data packets for which said communication controller has not normally received corresponding sub-acknowledgement signals, and

reducing said division size if the number of retransmitted divided data packets exceeds a predetermined value.

11. An apparatus transmitting data via a network comprising:

a communication controller arranged to divide a data packet transmitted by a host into a plurality of data packets, transmit said divided data packets to a receiving side, generate an acknowledgement signal, and transmit said acknowledgement signal to said host after it has normally received sub-acknowledgement signals from said receiving side for all of said divided data packets,

wherein each of said sub-acknowledgement signals indicates whether or not said receiving side has normally received a corresponding one of the divided data packets.

12. An apparatus transmitting data via a network according to claim 11, wherein said communication controller transmits said divided data packets without waiting for any of the sub-acknowledgment signals.

13. An apparatus for transmitting data via a network according to claim 11, wherein said communication controller retransmits only the divided data packets for which it has not normally received corresponding sub-acknowledgement packets.