Process for networking computers and/or computer networks and networking systems

• US 5,218,600 A
• Filed: 12/26/1990
• Issued: 06/08/1993
• Est. Priority Date: 06/19/1989
• Status: Expired due to Term

• Current Assignee: Richard Hirschmann GmbH & Co.
• Original Assignee: Richard Hirschmann GmbH & Co.
• Inventors: Schmid, Bernhard, Schenkyr, Rainer
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): BLUM, RUSSELL
• Application Number:
  US07/633,909
• Time in Patent Office: 895 Days
• Field of Search: 370/16, 370/16.1, 370/85.13, 370/85.2, 370/85.3, 340/825.01, 340/825.17, 371/8.2
• US Class Current: 370/217
• CPC Class Codes: H04L 12/437 Ring fault isolation or reconfiguration for SDH/SONET ring networks H04J3/085

Abstract

In a process for interconnecting computers and/or computer networks, the occurrence of an interruption in the network system is detected. A redundant connection is activated as a function of said interruption. The redundant connection is inactive in undisturbed operation. The presence of an interruption is detected by determining whether a data signal appears within a predetermined period of time at the connectors of a redundant connective device. Different criteria are provided to interrupt a closed connecting ring generated by the activation of the redundant connecting device when the initial interference in the network system is eliminated.

Claims

1. A process for interconnecting computers comprising the steps of:

utilizing a redundant connective device to detect an interruption in a network system;

activating said redundant connective device of the network system in response to an interruption detection;

deactivating the activated redundant connective device when no interruption is detected;

determining whether a data signal appears at two connectors of a redundant connective device connected to a network system within a first predetermined period of time;

wherein the step of activation and deactivation of said connective device comprises at least the step of placing a principal connecting path into a conducting or the non-conducting state; and

wherein a redundant connective device is provided at any location of the network system.

2. A process according to claim 1, further comprising the step providing at least two redundant connective devices in said network system.

3. A process according to claim 1, wherein said redundant connective device is activated if a data signal does not appear within a said first predetermined period of time at said two connectors.

4. A process according to claim 1, wherein said redundant connective device is deactivated if a data signal appears within a second predetermined period of time, at two connectors of said conductive device.

5. A process according to claim 4, wherein said second predetermined period of time is greater than the greatest running time mismatch of a data signal in the network system.

6. A process according to claim 4, wherein said second predetermined period of time in the case of the use of a CSMA/CD (Carrier Sense Multiple Access/Collision Detection) process is greater than a period of time corresponding to one half of the smallest permissible data packet.

7. A process according to claim 1, further comprising the step determining whether a data signal transmission time is longer than a period of time corresponding to the largest permissible data packet.

8. A process according to claim 7, wherein the redundant connective device is deactivated if a data signal transmission time is longer than the period of time corresponding to the largest permissible data packet.

9. A process according to claim 1, wherein said redundant connective device determines whether a data signal transmission time is shorter than the period of time corresponding to the smallest permissible data packet.

10. A process according to claim 9, further comprising the steps of:

counting occurrences of data signal transmission times which are shorter than the period of time corresponding to the smallest permissible data packet; and

deactivating said redundant connective device if a predetermined number of data signals shorter than the period of time corresponding to the smallest permissible data packet are detected.

11. A process according to claim 10, wherein said predetermined number of data signals is variable.

12. A process according to claim 1, further comprising the step of determining whether a data signal transmission and a data signal receiving process is simultaneous in the network system.

13. A process according to claim 12, further comprising the steps of:

counting the occurrences of simultaneous data signal transmissions and receptions in the network system; and

deactivating said redundant connective device if a predetermined number of simultaneous data signal transmission and receiving processes are counted.

14. A process according to claim 1, further comprising the step of determining whether the data signal duration of simultaneously occurring data signal transmissions and data signal receptions is greater than a predetermined period of time.

15. A process according to claim 14, wherein said redundant connective device is deactivated if said data signal duration of simultaneously occurring data signal transmissions and data signal receptions is greater than said predetermined period of time.

16. A process according to claim 15, wherein said predetermined period of time is smaller than or equal to one half of the duration of the smallest permissible data packet.

17. A process according to claim 16, wherein said predetermined period of time is less than 25.2 microseconds.

18. A network system for interconnecting computers comprising:

a redundant connective device responsive to a network system interruption detector wherein a connection path of said connective device is configured to switch into an active state in response to an interruption indication from said interruption detector, wherein said redundant connective device connects two nodal points of a network;

wherein said redundant connective device is configured to switch into an inactive state in response to a no-interruption indication from said interruption detector;

wherein said redundant connective device comprises at least two redundant interface cards and wherein said connection path is a redundant connecting path linking said interface cards;

wherein an interface card is placed into a segmented state upon deactivation of said redundant connective device and into a non-segmented state upon activation of said redundant connective device; and

a watch dog timer connected to said connective path.

19. A network system according to claim 18, wherein said interruption detector comprises means for determining an interruption in a network system connected to said redundant connective device.

20. A network system according to claim 18, wherein said redundant connective device comprises a fragment detection circuit means for detecting data signals with a duration smaller than a smallest permissible data signal length.

21. A network system according to claim 20, wherein said redundant connective device comprises a collision detection circuit means for detecting multiple access of computers and/or computer networks to the network system.

22. A network system according to 21, wherein said redundant connective device comprises a collision duration detection circuit means for detecting duration of a collision.

23. A network system according to claim 22, wherein said redundant connective device comprises a release circuit.

24. A network system for interconnecting computers comprising:

redundant connective means for detecting an interruption in a network system;

means for activating said redundant connective means of the network system in response to an interruption detection;

means for deactivating an activated redundant connective means when no interruption is detected;

wherein said means for activating and said means for deactivating said redundant connective means comprises at least means for switching a principal connecting path into a conducting or non-conducting state;

means for determining whether a data signal appears at two connectors of a redundant connective means connected to a network system within a first predetermined period of time; and

wherein said redundant connective means may be provided at any location of the network system.