Data exchange, data terminal accommodated in the same, data communication system and data communication method

• US 5,912,877 A
• Filed: 11/08/1995
• Issued: 06/15/1999
• Est. Priority Date: 12/07/1994
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kurisutani, Hiroyuki, Shirai, Nobuo, Sone, Yukio
• Primary Examiner(s): Jung, Min
• Application Number:
  US08/555,321
• Time in Patent Office: 1,315 Days
• Field of Search: 370/237, 370/217, 370/218, 370/225, 370/228, 370/235, 370/252
• US Class Current: 370/228
• CPC Class Codes: H04L 12/2854 Wide area networks, e.g. public data networks
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04Q 2213/13096 Digital apparatus individually associated with a subscriber line, digital line circuits
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13164 Traffic (registration, measurement,...)
• CPC Class Codes: H04Q 2213/13166 Fault prevention
• CPC Class Codes: H04Q 2213/13167 Redundant apparatus
• CPC Class Codes: H04Q 2213/13174 Data transmission, file transfer
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/13216 Code signals, frame structure
• CPC Class Codes: H04Q 2213/13296 Packet switching, X.25, frame relay
• CPC Class Codes: H04Q 2213/13353 Routing table, map memory
• CPC Class Codes: H04Q 3/66 Traffic distributors

Abstract

The present invention relates to a data exchange and a data exchanging method each suitable for a communication system which tends to be congested due to high-speed communication such as a frame relay network. The data exchange that accommodates plural data terminals via terminal trunks includes a congestion status detecting unit for detecting the congestion status in a standard transit trunk, and the transit trunk control unit including a first alternate control unit that controls to transfer data to be transferred by a roundabout route using a backup transit trunk, based on detection information from the congestion status detecting unit. The purpose of the present invention is to suppress the occurrence of congestion or the frame disposal of a frame at a congestion occurrence time.

Claims

1. A data exchange accommodating plural data terminals via terminal trunks and including transit trunk control means for transferring selectively data to be transferred from the terminal trunk to a standard transit line or a backup transit line, said transit trunk control means connected to said standard transit line transferring data to a predetermined transfer destination in a transit system, and said backup transit line which transfers data alternately to the predetermined transfer destination, said data exchange comprising:

congestion status detecting means for detecting a congestion status in said standard transit trunk;

said transit trunk control means having first alternate control means to transfer alternately data to be transferred using said backup transit line, based on detection information from said congestion status detecting means; and

alternate priority setting means sets priority to data link identification information of every terminal trunk; and

wherein said first alternate control means performs an alternate control to said backup transit line, based on the priority set by said alternate priority setting means.

2. The data exchange according to claim 1, wherein said plural data terminals are formed as at least one group;

and wherein said alternate priority setting means sets the priority to data link identification information set every terminal trunk of said group.

3. The data exchange according to claim 2, wherein plural backup transit lines are connected;

and wherein said transit trunk control means includes a second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion state detecting means.

4. The data exchange according to claim 2, further comprising trunk use rate monitoring means for monitoring the trunk use rate;

and wherein said plural backup transit lines are connected; and

wherein said transit trunk control means includes;

second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion status detecting means; and

return transferring means for returning sequentially the trunk to the original standard transit line to transfer data, when said congestion status detecting means detects a release from the congestion status of said standard transit line, provided that the trunk use rate is smaller than a predetermined value, based on trunk use rate information from said trunk use rate monitoring means.

5. The data exchange according to claim 2, wherein said plural backup transit lines are connected;

and wherein said transit trunk control means includes;

second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion status detecting means; and

committed information rate varying means for varying a committed information rate defined by a terminal trunk when it is judged that said standard transit line is almost in a congestion status, based on detection information from said congestion state detecting means.

6. The data exchange according to claim 2, further comprising trunk use rate monitoring means for monitoring a trunk use rate;

and wherein said transit trunk control means includes return transferring means for returning sequentially the trunk to the original standard transit line to transfer data when said congestion status detecting means detects a release from the congestion status of said standard transit line, provided that the trunk use rate is smaller than a predetermined value, based on trunk use rate information from said trunk use rate monitoring means.

7. The data exchange according to claim 1, wherein plural backup transit lines are connected;

and wherein said transit trunk control means includes a second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion status detecting means.

8. The data exchange according to claim 1, further comprising trunk use rate monitoring means for monitoring the trunk use rate;

and wherein said plural backup transit lines are connected; and

wherein said transit trunk control means includes;

second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion status detecting means; and

return transferring means for returning sequentially the trunk to the original standard transit line to transfer data, when said congestion status detecting means detects a release from the congestion status of said standard transit line, provided that the trunk use rate is smaller than a predetermined value, based on trunk use rate information from said trunk use rate monitoring means.

9. The data exchange according to claim 1, wherein said plural backup transit lines are connected;

and wherein said transit trunk control means includes;

second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion status detecting means; and

committed information rate varying means for varying a committed information rate defined by a terminal trunk when it is judged that said standard transit line is almost in a congestion status, based on detection information from said congestion state detecting means.

10. The data exchange according to claim 1, further comprising:

flow parameter setting means for setting a flow parameter used to perform a flow control in said transit system; and

flow parameter reporting means for reporting said changed flow parameter to said variable-length data terminal when a flow parameter is changed by said flow parameter setting means.

11. The data exchange according to claim 2, further comprising trunk use rate monitoring means for monitoring a trunk use rate;

and wherein said transit trunk control means includes return transferring means for returning sequentially the trunk to the original standard transit line to transfer data when said congestion status detecting means detects a release from the congestion status of said standard transit line, provided that the trunk use rate is smaller than a predetermined value, based on trunk use rate information from said trunk use rate monitoring means.

12. A data exchange accommodating plural data terminals via terminal trunks and including transit trunk control means for transferring selectively data to be transferred from the terminal trunk to a standard transit line or a backup transit line, said transit trunk control means connected to said standard transit line transferring data to a predetermined transfer destination in a transit system, and said backup transit line which transfers data alternately to the predetermined transfer destination, said data exchange comprising:

congestion status detecting means for detecting a congestion status in said standard transit trunk,

said transit trunk control means having first alternate control means to transfer alternately data to be transferred using said backup transit line, based on detection information from said congestion status detecting means;

wherein plural backup transit lines are connected; and

wherein said transit trunk control means includes second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion status detecting means.

13. A data exchange accommodating plural data terminals via terminal trunks and including transit trunk control means for transferring selectively data to be transferred from the terminal trunk to a standard transit line or a backup transit line, said transit trunk control means connected to said standard transit line transferring data to a predetermined transfer destination in a transit system, and said backup transit line which transfers data alternately to the predetermined transfer destination, said data exchange comprising:

congestion status detecting means for detecting a congestion status in said standard transit trunk;

said transit trunk control means having first alternate control means to transfer alternately data to be transferred using said backup transit line, based on detection information from said congestion status detecting means;

trunk use rate monitoring means for monitoring the trunk use rate; and

wherein said plural backup transit lines are connected; and

wherein said transit trunk control means includes;

second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion status detecting means; and

return transferring means for returning sequentially the trunk to the original standard transit line to transfer data, when said congestion status detecting means detects a release from the congestion status of said standard transit line, provided that the trunk use rate is smaller than a predetermined value, based on trunk use rate information from said trunk use rate monitoring means.

14. A data exchange accommodating plural data terminals via terminal trunks and including transit trunk control means for transferring selectively data to be transferred from the terminal trunk to a standard transit line or a backup transit line, said transit trunk control means connected to said standard transit line transferring data to a predetermined transfer destination in a transit system, and said backup transit line which transfers data alternately to the predetermined transfer destination, said data exchange comprising:

congestion status detecting means for detecting a congestion status in said standard transit trunk;

said transit trunk control means having first alternate control means to transfer alternately data to be transferred using said backup transit line, based on detection information from said congestion status detecting means;

wherein said plural backup transit lines are connected; and

wherein said transit trunk control means includes;

second alternate control means for stepwise-bypassing data to be transferred with said standard transit line in use to said plural backup transit lines, based on detection information from said congestion status detecting means; and

committed information rate varying means for varying a committed information rate defined by a terminal trunk when it is judged that said standard transit line is almost in a congestion status, based on detection information from said congestion state detecting means.

15. A data exchange accommodating plural data terminals via terminal trunks and including plural standard transit lines transferring data to a predetermined transfer destination in a transit system, and a backup transit line for alternatively transferring data to said predetermined transfer destination, said data exchange comprising:

data link identification information setting means for setting data link identification information corresponding to data link identification information of every said terminal trunk, to said plural standard transit lines;

congestion status detecting means for detecting the congestion status in said standard transit line; and

transit trunk control means for controlling to transfer data to be transferred from said terminal trunk using a standard transit line corresponding to data link identification information, and controlling to transfer data using a standard transit line to which another data link identification information is set when congestion occurring in said standard transit line is detected based on detection information from said congestion status detecting means.

16. The data exchange according to claim 15, further comprising trunk use rate monitoring means for monitoring a trunk use rate;

and wherein said transit trunk control means includes return transferring means for returning sequentially the trunk to the original standard transit line to transfer data when said congestion status detecting means detects a release from the congestion status of said standard transit line, provided that the trunk use rate is smaller than a predetermined value, based on trunk use rate information from said trunk use rate monitoring means.

17. The data exchange according to claim 15, further comprising trunk use rate monitoring means for monitoring a trunk use rate;

and wherein said transit trunk control means controls a data transfer using a standard transit line with the lowest trunk use rate, based on trunk use rate information from said trunk use rate monitoring means, when congestion occurring in said standard transit line is detected.

18. The data exchange according to claim 15, wherein communications are mad with said standard transit line separated into the band in a packet system and the band in a frame relay system.

19. The data exchange according to claim 18, further comprising:

transmission queue monitoring means for monitoring transmission queues in a packet system and a frame relay system; and

band ratio varying means for varying the ratio of the band in said packet system and the band in said frame relay system, based on transmission queue monitoring information from said transmission queue monitoring means.

20. The data exchange according to claim 19, wherein said transmission queue monitoring information from said transmission queue monitoring means is information regarding a congestion of a transmission queue.

21. The data exchange according to claim 19, wherein said transmission queue monitoring information from said transmission queue monitoring means is information regarding a delay of a transmission queue.

22. A data exchange accommodating plural data terminals via terminal trunks and including transit trunk control means for transferring selectively data to be transferred from the terminal trunk to a standard transit line or a backup transit line, said transit trunk control means connected to said standard transit line transferring data to a predetermined transfer destination in a transit system, and said backup transit line which transfers data alternately to the predetermined transfer destination, said data exchange comprising:

congestion status detecting means for detecting a congestion status in said standard transit trunk;

said transit trunk control means having first alternate control means to transfer alternately data to be transferred using said backup transit line, based on detection information from said congestion status detecting means;

trunk use rate monitoring means for monitoring a trunk use rate; and

wherein said transit trunk control means includes return transferring means for returning sequentially the trunk to the original standard transit line to transfer data when said congestion status detecting means detects a release from the congestion status of said standard transit line, provided that the trunk use rate is smaller than a predetermined value, based on trunk use rate information from said trunk use rate monitoring means.

23. A data exchange accommodating plural data terminals via terminal trunks and including transit trunk control means for transferring selectively data to be transferred from the terminal trunk to a standard transit line or a backup transit line said transit trunk control means connected to said standard transit line transferring data to a predetermined transfer destination in a transit system, and said backup transit line which transfers data alternately to the predetermined transfer destination, said data exchange comprising:

congestion status detecting means for detecting a congestion status in said standard transit trunk;

said transit trunk control means having first alternate control means to transfer alternately data to be transferred using said backup transit line, based on detection information from said congestion status detecting means;

wherein communications are made with said standard transit line separated into the band in a packet system and the band in a frame relay system.

24. The data exchange according to claim 23, further comprising:

transmission queue monitoring means for monitoring transmission queues in a packet system and a frame relay system; and

band ratio varying means for varying the ratio of the band in said packet system and the band in said frame relay system, based on transmission queue monitoring information from said transmission queue monitoring means.

25. The data exchange according to claim 24, wherein said transmission queue monitoring information from said transmission queue monitoring means is information regarding a congestion of a transmission queue.

26. The data exchange according to claim 24, wherein said transmission queue monitoring information from said transmission queue monitoring means is information regarding a delay of a transmission queue.

27. A data terminal accommodated in a data exchange via a terminal trunk, said data terminal comprising:

a standard transit line for transferring data to a predetermined transfer destination in a transit system;

backup transit line for transferring data to be transferred with said standard transit line to said predetermined transfer destination by a roundabout route;

data link identification setting means for setting data link identification information corresponding to data link information of said terminal trunk, to said standard transit line and said backup transit line,

transit trunk control means for transferring selectively data to be transferred from said terminal trunk via said standard transit line corresponding to data link information or via said backup transit line corresponding to another data link information when congestion occurs in said standard transit line;

flow parameter setting means for setting a flow parameter to perform a flow control in said transit system;

flow parameter reporting means for reporting a changed flow parameter to said variable-length data terminal when said flow parameter setting means changes said flow parameter; and

flow control means for performing a flow control according to a flow parameter reported from said flow parameter reporting means.

28. A data communication system, comprising:

a transmitting data exchange accommodating a transmitting data terminal via a terminal trunk, for exchanging data; and

a receiving data exchange accommodating a receiving data terminal via a terminal trunk, for exchanging data;

said transmitting exchange being connected to said receiving data exchange via a standard transit line for transferring data to a predetermined transfer destination in a transit system and a backup transit line for transferring data to be transferred with said standard transit line to said predetermined transfer destination by a roundabout route;

data link identification setting means for setting data link identification information corresponding to data link information of said terminal trunk, to said standard transit line and said backup transit line;

said transmitting data exchange including transit trunk control means for transferring selectively data to be transferred from said terminal trunk to said standard transit line corresponding to data link information or said backup transit line, corresponding to another data link information and congestion status detecting means for detecting the congestion status of said standard transit line;

said transit trunk control means including first alternate control means for controlling to transfer said data to be transferred by a roundabout route using said backup transit line, based on the detection information from said congestion status detecting means.

29. A data communicating method in which a transmitting data exchange accommodating a transmitting data terminal via a terminal trunk for exchanging data, and a receiving data exchange accommodating a receiving data terminal via said terminal trunk for exchanging data are prepared;

said method comprises;

setting data link identification information corresponding to data link information of said terminal trunk, to said standard transit line and said backup transit line;

transferring data from said transmitting data exchange to said receiving data exchange, using a standard transit line being transferable data to a predetermined transfer destination in a transit system or a backup transit line transferring data to be transferred with said standard transit line to said predetermined transfer destination by a roundabout route;

said transmitting data exchange selectively transfers data from said terminal trunk to said standard transit line corresponding to data link information or said backup transit line, corresponding to another data link information detecting the congestion status in said transit trunk, and transfers data to be transferred using said backup transit line, by a roundabout route, based on the detection information of the congestion status.