Generating acknowledgement signals in a data communication system

• US 6,282,172 B1
• Filed: 04/01/1997
• Issued: 08/28/2001
• Est. Priority Date: 04/01/1997
• Status: Expired due to Fees

• Current Assignee: PHX Communications Incorporated
• Original Assignee: Yipes Communications, Inc.
• Inventors: Kaminski, Peter, Robles, Frank R.
• Primary Examiner(s): Cheng, Joe H.
• Assistant Examiner(s): Nguyen, Kim T.
• Application Number:
  US08/825,682
• Time in Patent Office: 1,610 Days
• Field of Search: 370/230, 370/232, 370/233, 370/234, 370/235, 370/236, 370/237, 370/231, 370/428
• US Class Current: 370/230
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1835 Buffer management
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link

Abstract

A system for controlling the flow of data receives a data packet from a source node for transmission across a communication medium to a destination node. The system generates an acknowledgment signal indicating receipt of the data packet at the destination node. The acknowledgment signal is generated before completing transmission of the data packet to the destination node. The system then transmits the acknowledgment signal to the source node, regardless of whether transmission of the data packet to the destination node is complete. Generation of the acknowledgment signal is performed by a device other than the destination node. The system buffers the received data packet until an actual acknowledgment signal is received from the destination node. When the actual acknowledgment signal is received, the buffered data packet is deleted from the buffer.

Claims

1. A method for transmitting acknowledgement signals in a data communications system, comprising:

receiving at an intermediate node, a data packet from a source node for transmission across a communication medium to a destination node;

determining, based upon a previous communication with the destination node, whether the destination node is capable of receiving the data packet received by the intermediate node;

generating an acknowledgment signal at the intermediate node if the destination node is capable of receiving the data packet received at the intermediate node; and

transmitting the generated acknowledgment signal from the intermediate node to the source node before transmission of the data packet to the destination node.

2. The method of claim 1, wherein generating the acknowledgment signal further comprises monitoring the destination node to determine the capabilities of the destination node.

3. The method of claim 1, wherein the intermediate node is a first switch, the method further comprising transmitting the data packet from the first switch to a second switch, and wherein transmitting the generated acknowledgment signal occurs before transmitting the data packet from the first switch to a second switch begins.

4. The method of claim 3, further comprising buffering the received data packet until an actual acknowledgment signal from the destination node is received at the first switch.

5. The method of claim 3, further comprising deleting the buffered data packet after receiving the actual acknowledgment signal at the first switch.

6. A network switching device, comprising:

a receiver to receive a data packet from a source node for transmission of the data packet across a communication medium coupled with the network switching device and a destination node;

an acknowledgment generator coupled with the receiver to generate an acknowledgment signal indicating receipt of the data packet at the destination node, wherein the acknowledgment generator generates the acknowledgment signal if the destination node is capable of receiving the data packet; and

a transmitter coupled with the acknowledgment generator to transmit the acknowledgment signal to the source node before transmission of the data packet to the destination node.

7. The network switching device of claim 6, wherein the source node monitors the destination node to determine the capabilities of the destination node.

8. The network switching device of claim 6, further comprising a second transmitter to transmit the data packet to a second network switching device, wherein the transmitter transmits the acknowledgment signal to the source node before the second transmitter begins to transmit the data packet to the second network switching device.

9. The network switching device of claim 8, further comprising a buffer coupled with the receiver to store the received data packet until an actual acknowledgment signal is received from the destination node.

10. The network switching device of claim 8, wherein the buffered data packet is deleted from the buffer upon receipt of the actual acknowledgment signal from the destination node.

11. A method for generating and transmitting acknowledgement signals in a data communications system, comprising:

receiving at a first network switch a data packet from a source node;

generating an acknowledgment signal at the first network switch, wherein the acknowledgement signal falsely indicates that a destination node received the data packet; and

transmitting the generated acknowledgment signal from the first network switch to the source node before beginning transmission of the data packet to a second network switch.

12. The method of claim 11, further comprising:

determining whether a buffer associated with the first network switch has reached a buffer limit; and

transmitting a source quench instruction to the source node to reduce the rate at which data is transmitted from the source node to the first network switch if the first network switch has reached the buffer limit.

13. The method of claim 11, further comprising:

transmitting the data packet from the first network switch to the second network switch; and

retransmitting the data packet from the first network switch to the second network switch if an actual acknowledgement signal is not received within a predetermined period of time.

14. The method of claim 11, wherein transmitting includes transmitting the generated acknowledgment signal from the first network switch to the source node substantially before beginning transmission of the data packet to a second network switch, the method further including:

buffering the received data packet; and

deleting the buffered data packet after receiving an actual acknowledgment signal from the second network switch.

15. The method of claim 11, wherein generating the acknowledgment signal comprises:

determining by communicating with the second network switch, whether the second network switch is capable of receiving the data packet; and

transmitting the acknowledgment signal to the second network switch if the second network switch is capable of receiving the data packet.

16. The method of claim 11, wherein generating includes generating the acknowledgment signal if a destination node is capable of receiving the data packet.

17. The method of claim 11, wherein transmitting includes transmitting the acknowledgment signal if a destination node is capable of receiving the data packet.

18. The method of claim 11, wherein generating includes generating the acknowledgment signal if the second network switch is capable of receiving the data packet.

19. The method of claim 11, wherein transmitting includes transmitting the acknowledgment signal if the second network switch is capable of receiving the data packet.

20. The method of claim 19, further comprising the first network switch monitoring the capabilities of the second network switch to handle the data packet.

21. The method of claim 11, further comprising the source node monitoring the capabilities of the destination node to receive the data packet.

22. A processor-readable medium having stored thereon sequences of instructions that when executed cause a processor to:

receive at a first network switch a data packet from a source node;

generate an acknowledgment signal at the first network switch, wherein the acknowledgement signal falsely indicates that a destination node received the data packet; and

transmit the generated acknowledgment signal from the first network switch to the source node before beginning transmission of the data packet to a second network switch.

23. The processor-readable medium of claim 22, wherein the instructions further comprise instructions causing the processor to:

transmit the data packet from the first network switch to the second network switch; and

retransmit the data packet from the first network switch to the second network switch if an actual acknowledgement signal is not received within a predetermined period of time.

24. The processor-readable medium of claim 22, wherein the instructions to transmit further comprise instructions causing the processor to:

determine by communicating with the second network switch, whether the second network switch is capable of receiving the data packet; and

transmit the acknowledgment signal to the second network switch if the second network switch is capable of receiving the data packet.

25. The processor-readable medium of claim 22, wherein the instructions to transmit further comprise instructions causing the processor to:

transmit the acknowledgment signal if a destination node is capable of receiving the data packet.

26. A network switching device, comprising:

a receiver to receive a data packet from a source node via a communication link;

an acknowledgment generator coupled with the receiver to generate an acknowledgment signal that indicates receipt of the data packet at a destination node; and

a transmitter coupled with the acknowledgment generator to transmit the acknowledgment signal to the source node before transmission of the data packet to a second network switching device begins.

27. The network switching device of claim 26, further comprising a second transmitter to transmit the data packet to the second network switching device.

28. The network switching device of claim 26, wherein the acknowledgment generator generates the acknowledgment signal if the destination node is capable of receiving the data packet.

29. The network switching device of claim 26, wherein the transmitter transmits the acknowledgment signal if the destination node is capable of receiving the data packet.

30. The network switching device of claim 26, wherein the acknowledgment generator generates the acknowledgment signal if the second network switching device is capable of receiving the data packet.

31. The network switching device of claim 26, wherein the transmitter transmits the acknowledgment signal if the second network switching device is capable of receiving the data packet.

32. The network switching device of claim 26, further including a buffer coupled with the receiver and to store the received data packet until the received data packet is deleted from the buffer after receiving an actual acknowledgment signal from the second network switching device.

33. A network switching device, comprising:

means for receiving a data packet from a source node;

means for generating an acknowledgment signal at a first network switch in response to determining that a second network switching device is capable of handling the received data packet, wherein the acknowledgement signal falsely indicates that a destination node received the data packet; and

means for transmitting the generated acknowledgment signal from the first network switch to the source node.

34. The network switching device of claim 33, further comprising means to determine when to generate the acknowledgement signal at the first network switch.

35. The network switching device of claim 33, wherein the means for transmitting is a means for transmitting the generated acknowledgment signal from the first network switch to the source node substantially before beginning transmission of the data packet to a second network switch.

36. A method for generating and transmitting acknowledgement signals in a data communications system, comprising:

receiving at a first network switch a data packet from a source node;

communicating with a second network switch to determine whether the second network switch is capable of receiving the data packet;

generating an acknowledgment signal at the first network switch, wherein the acknowledgement signal falsely indicates that a destination node received the data packet; and

transmitting the generated acknowledgment signal from the first network switch to the source node if the second network switch is capable of receiving the data packet.

37. The method of claim 36, wherein communicating occurs after generating.

38. The method of claim 36, wherein transmitting includes transmitting the generated acknowledgment signal from the first network switch to the source node before beginning to transmit the data packet to the second network switch.