Data transfer apparatus and method using congestion recovery-type and congestion avoidance-type data transfers

• US 6,125,397 A
• Filed: 06/03/1998
• Issued: 09/26/2000
• Est. Priority Date: 06/03/1997
• Status: Expired due to Fees

• Current Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Mitsutake, Katsuya, Kamizawa, Koh, Yoshimura, Kouichi
• Primary Examiner(s): Matar, Ahmad F.
• Assistant Examiner(s): Barot, Bharat
• Application Number:
  US09/089,219
• Time in Patent Office: 846 Days
• Field of Search: 709/223-224, 709/226, 709/232-236, 709/250, 709/200, 370/229-239, 370/253, 370/412-418
• US Class Current: 709/235
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/745 Reaction in network
• CPC Class Codes: H04L 47/803 Application aware
• CPC Class Codes: H04L 47/822 Collecting or measuring resource availability data
• CPC Class Codes: H04L 47/83 based on usage prediction

Abstract

A data transfer apparatus and method uses recovery-type congestion control and avoidance-type congestion control. A bandwidth determination unit determines a requested bandwidth for a congestion avoidance-type data transfer in accordance with control information communicated between applications prior to the congestion avoidance-type data transfer. A bandwidth estimation unit estimates a bandwidth having been used by a congestion recovery-type data transfer in accordance with the control information communicated between applications prior to the congestion recovery-type data transfer. A management information memory stores information data of all the congestion avoidance-type data transfers and congestion recovery-type data transfers that use the bandwidth at a particular moment (i.e., simultaneously). A bandwidth allocation unit determines whether a newly requested congestion avoidance-type data transfer can be performed in accordance with an unused bandwidth and a bandwidth requested by the new data transfer, and allocates a certain amount of bandwidth to the new congestion avoidance-type data transfer. A data transfer instruction unit instructs an application to perform new data transfer.

Claims

1. A method of performing data transfers on a network, comprising the steps of:

performing a congestion recovery-type of data transfer of first data; and

performing a congestion avoidance-type of data transfer of second data that is different from the first data, the congestion avoidance-type of data transfer being performed simultaneously with the congestion recovery-type of data transfer;

the congestion recovery-type of data transfer changing a transfer rate of the first data based upon congestion detected on the network, whereas the congestion avoidance-type of data transfer does not chance a transfer rate of the second data based on the congestion detected on the network.

2. A data transfer apparatus in a network system that includes a first computer, a plurality of second computers and a network connecting the first computer and the plurality of second computers with each other, the plurality of second computers performing data transfers to the first computer simultaneously through an identical path on the network in accordance with requests from applications on the plurality of second computers, the data transfer apparatus comprising:

a congestion detector that detects congestion on the network;

a first transfer controller that starts a first type of data transfer using an amount of the network and decreases the amount of the network used by the first type of data transfer in accordance with congestion detected by the congestion detector;

a resource monitor that monitors the first type of data transfer to calculate the amount of the network used by the first type of data transfer;

an allocation unit that determines an amount of the network to be used by a succeeding second type of data transfer in accordance with the amount of the network used by the first type of data transfer; and

a second transfer controller that starts the succeeding second type of data transfer using the amount of the network determined by the allocation unit, said second transfer controller does not change a transfer rate of the succeeding second type of data transfer based on the congestion detected by the congestion detector.

3. The data transfer apparatus as set forth in claim 2, wherein the resource monitor determines the amount of the network used by the first type of data transfer by monitoring control packets of a connection sequence between the first computer and the second computers.

4. The data transfer apparatus as set forth in claim 2, wherein the resource monitor determines the amount of the network used by the first type of data transfer by estimating a representative value of a bandwidth and a time variation of the bandwidth used by the first type of data transfer.

5. The data transfer apparatus as set forth in claim 4, wherein the resource monitor prepares predetermined relationships between categories and bandwidths, classifies the first type of data transfer as one of the categories according to a process parameter of the application that requests the first type of data transfer, and sets the bandwidth corresponding to the category into which the first type of data transfer is classified as the representative value of the bandwidth.

6. The data transfer apparatus as set forth in claim 5, wherein the process parameter includes at least one of a type of the application, an amount of data to be transferred by the application, and a type of computer on which the application is executed.

7. The data transfer apparatus as set forth in claim 4, wherein the resource monitor estimates the time variation by multiplying a predetermined coefficient by a short time variation of the representative value of the bandwidth.

8. The data transfer apparatus as set forth in claim 2, wherein the allocation unit calculates an amount of the network used by a previous second type of data transfer, calculates an available amount of the network by subtracting the amount of the network used by the first type of data transfer and the amount of the network used by the previous second type of data transfer from a capacity of the network, and determines the amount of the network to be used by a succeeding second type of data transfer to be within the available amount of the network.

9. The data transfer apparatus as set forth in claim 2, wherein the second computers are clients and the first computer is a server.

10. The data transfer apparatus as set forth in claim 2, wherein the first computer is a print server.

11. The data transfer apparatus as set forth in claim 2, wherein the resource monitor is provided on a switch in the network.

12. The data transfer apparatus as set forth in claim 2, wherein the resource monitor is provided on an entrance of the first computer.

13. The data transfer apparatus as set forth in claim 2, wherein the first computer is a network communication control server.

14. The data transfer apparatus as set forth in claim 2, wherein the first type of data transfer is a congestion recovery-type of data transfer, and the second type of data transfer is a congestion avoidance-type of data transfer.

15. The data transfer apparatus as set forth in claim 2, wherein the allocation unit determines the amount of the network to be used by the succeeding second type of data transfer by dividing the succeeding second type of data transfer into intervals, and the resource monitor calculates a time variation of the bandwidth used by the succeeding second type of data transfer based on an interval between arrival times of packets.

16. A data transfer apparatus that performs data transfers among plural computers connected with each other by a network, the data transfer apparatus comprising:

a congestion detector that detects congestion of the data transfers on the network;

a first transfer controller that performs data transfers among the computers by controlling an amount of the network used by the data transfers in accordance with the detection of congestion by the congestion detector;

a resource monitor that monitors an amount of the network used by the data transfers on a path where the data transfers converge; and

a second transfer controller that performs a succeeding data transfer using an amount of the network that is determined in accordance with the amount of the network used by the data transfers determined by said resource monitor said second transfer controller does not chance a transfer rate of the succeeding data transfer based on the detection of congestion by the congestion detector.

17. The data transfer apparatus as set forth in claim 16, wherein the resource monitor determines the amount of the network used by the data transfers controlled by the first controller by estimating a representative value of a bandwidth and a time variation of the bandwidth used by the data transfers controlled by first controller.

18. The data transfer apparatus as set forth in claim 16, wherein one of the plurality of computers is a print server.

19. The data transfer apparatus as set forth in claim 16, wherein the resource monitor is provided on a switch in the network.

20. The data transfer apparatus as set forth in claim 16, wherein the data transfers controlled by the first controller are congestion recovery-type of data transfers, and the succeeding data transfer controlled by the second controller is a congestion avoidance-type of data transfer.

21. A method for performing data transfers between a plurality of computers connected with each other by a network, comprising the steps of:

detecting congestion on the network;

performing data transfers among the computers by controlling an amount of the network used by the data transfers in accordance with the detection of congestion;

monitoring an amount of the network used by the data transfers on a path where the data transfers converge; and

performing a succeeding data transfer using an amount of the network that is determined in accordance with the amount of the network used by the data transfers determined by said monitoring, said succeeding data transfer taking place at a transfer rate that does not change based on the detection of congestion.

22. The method as set forth in claim 21, wherein the monitoring step includes determining the amount of the network used by the data transfers controlled in accordance with the detection of congestion by estimating a representative value of a bandwidth and a time variation of the bandwidth used by the data transfers controlled in accordance with the detection of congestion.

23. The method as set forth in claim 22, wherein the monitoring step includes preparing predetermined relationships between categories and bandwidths, classifying the data transfer controlled in accordance with the detection of congestion as one of the categories according to a process parameter of the application that requests the data transfer, and setting the bandwidth corresponding to the category into which the data transfer is classified as the representative value of the bandwidth.

24. The method as set forth in claim 23, wherein the process parameter includes at least one of a type of the application, an amount of data to be transferred by the application, and a type of computer on which the application is executed.

25. The method as set forth in claim 22, wherein the monitoring step includes estimating the time variation by multiplying a predetermined coefficient by a short time variation of the representative value of the bandwidth.

26. The method as set forth in claim 21, wherein one of the plurality of computers is a print server.

27. The method as set forth in claim 21, wherein the monitoring step is performed on a switch in the network.

28. The method as set forth in claim 21, wherein the data transfers controlled in accordance with the detection of congestion are congestion recovery-type of data transfers, and the succeeding data transfer is a congestion avoidance-type of data transfer.

29. A carrier wave encoded to transmit a control program that is readable by a computer performing data transfers over a network, the control program including instructions for causing the computer to execute the steps of:

detecting congestion on the network;

performing data transfers among computers connected with each other by the network by controlling an amount of the network used by the data transfers in accordance with the detection of congestion;

monitoring an amount of the network used by the data transfers on a path where the data transfers converge; and

performing a succeeding data transfer using an amount of the network that is determined in accordance with the amount of the network used by the data transfers determined by said monitoring, said succeeding data transfer taking place at a transfer rate that does not change based on the detection of congestion.

30. The carrier wave as set forth in claim 29, wherein the carrier wave is stored on a recording medium that is readable by the computer performing the data transfers.

31. The carrier wave as set forth in claim 29, wherein the instructions for the monitoring step include instructions to determine the amount of the network used by the data transfers controlled in accordance with the detection of congestion by estimating a representative value of a bandwidth and a time variation of the bandwidth used by the data transfers controlled in accordance with the detection of congestion.

32. The carrier wave as set forth in claim 31, wherein the instructions for the monitoring step include instructions to prepare predetermined relationships between categories and bandwidths, classify the data transfer controlled in accordance with the detection of congestion as one of the categories according to a process parameter of the application that requests the data transfer, and set the bandwidth corresponding to the category into which the data transfer is classified as the representative value of the bandwidth.

33. The carrier wave as set forth in claim 32, wherein the process parameter includes at least one of a type of the application, an amount of data to be transferred by the application, and a type of computer on which the application is executed.

34. The carrier wave as set forth in claim 31, wherein the instructions for the monitoring step include instructions to estimate the time variation by multiplying a predetermined coefficient by a short time variation of the representative value of the bandwidth.

35. The carrier wave as set forth in claim 29, wherein the computer is a print server.

36. The carrier wave as set forth in claim 29, wherein the data transfers controlled in accordance with the detection of congestion are congestion recovery-type of data transfers, and the succeeding data transfer is a congestion avoidance-type of data transfer.