Resource allocation in distributed control systems

• US 4,747,130 A
• Filed: 12/17/1985
• Issued: 05/24/1988
• Est. Priority Date: 12/17/1985
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Inventors: Ho, Jen-Lie
• Primary Examiner(s): Brown, Thomas W.
• Application Number:
  US06/810,070
• Time in Patent Office: 889 Days
• Field of Search: 370/60, 370/67, 370/66, 370/63, 370/58, 370/86, 370/89, 379/269, 379/274, 379/273, 379/221, 340/825.05, 340/825.08, 364/200, 364/900
• US Class Current: 379/269
• CPC Class Codes: H04Q 11/0407 using a stored programme control

Abstract

In a distributed processing telecommunication switching system comprising a plurality of switching modules, the individual modules control substantially all telephone call control processing actions, including the selection of an available port of a multiport hunt group, without requiring the assistance of a central processor. Each module includes a processor, a plurality of ports connected to customer lines and interoffice trunks, a plurality of outlets for setting up intermodule connections, and a switching network for interconnecting ports and outlets within a module. The module processors communicate with each other by a high speed common data communication facility connected to all processors. This data communication facility is used for communicating intermodule call control messages and port availability data to allow port hunts to be accomplished without using a central processor.

Claims

1. In a distributed control system having at least one shared resource and comprising a plurality of processors each having its own local data base, a method of hunting for an available shared resource, comprising the steps of:

a. selecting, in a first one of said processors, a shared resource, using data in the local data base of that processor, as the hunted resource;

b. broadcasting from said first one of said processors to others of said plurality of processors a data message comprising an identity of said selected shared resource; and

c. in response to said message, changing the local data base of each of said other processors to indicate that said selected shared resource is not available.

17. The method of claim 1, wherein said plurality of processors comprises at least three processors.

18. The method of claim 17 wherein said at least one shared resource comprises at least two shared resources.

19. The method of claim 17 wherein said at least one shared

20. The method of claim 19 wherein said broadcasting step comprises the step of broadcasting over a local area network interconnecting said plurality of processors.

2. In a distributed control system having at least one shared resource and comprising a plurality of processors each having its own local base base, a method of hunting for an available shared resource comprising the steps of:

a. in a first one of said processor, selecting a candidate avaialble shared resource using availability data in the local data base of said first one of said processors;

b. broadcasting from said first one of said processors to others of said plurality of processors a message comprising an identity of said candidate available shared resource;

c. in response to receipt of said message, recording in the local data base of each said other processors that said candidate available shared resource is not available;

d. following step b, testing whether said candidate available shared resource is indicated as being available in the local data base of said first processor; and

e. if said test of step d shows that said candidate available resource is available, selecting said candidate available resource as the hunted resource.

3. The method of claim 2 further comprising the following step after step d:

f. if said test shows that said candidate resource is not available, repeating steps a, b, c, d, and f;

otherwise, executing step e.

4. The method of claim 3, wherein said step b further comprises the step of sending said message to said first processor, and wherein said step d comprises the steps of:

receiving said message in said first processor; and

testing whether said candidate resource is indicated as being available in the local data base of said first processor.

5. In a distributed control telecommunication switching system having a multiplicity of ports and comprising a plurality of modules each having a processor with a local data base, each module comprising a subgroup of said multiplicity of ports, wherein a subset of said multiplicity of ports comprises a multiport group, a method of hunting for an available port in said multiport group, comprising the steps of:

a. selecting, in a first one of said processors, an available port in said multiport group as the hunted port, using data in the local data base of that processor;

b. broadcasting from said first one of said processors to others of said plurality of processors a data message comprising an identity of said hunted port; and

c. in response to said message, changing the data base of each of said other processors to indicate that said hunted port is not available.

6. In a distributed control telecommunication switching system having a multiplicity of ports and comprising a plurality of modules each having a processor with a local data base, each module comprising a subgroup of said multiplicity of ports, wherein a subset of said multiplicity of ports comprises a multiport group, a method of hunting for an available port in said multiport group, comprising the steps of:

a. selecting, in a first one of said processors, an available candidate port in said multiport group, using data in the local data base of that processor without changing that local data base to indicate that said candidate port is not available;

b. broadcasting from said first one of said processors to others of said plurality of processors a message comprising an identity of said candidate port;

c. in response to receipt of said message, recording in the local data base of each of said other processors that said candidate port is not available;

d. following step b, testing whether said candidate port is indicated as being available in the local data base of said first processor; and

e. if said test of step d shows that said candidate port is available, selecting said candidate port as the hunted port.

7. The method of claim 6 further comprising the following step after step d:

f. if said test shows that said candidate port is not available, repeating steps a, b, c, d, and f;

otherwise, executing step e.

8. The method of claim 7, wherein said step b further comprises the step of sending said message to said first processor, and wherein said step d comprises the steps of:

receiving said message in said first processor; and

testing whether said candidate port is indicated as being available in the local data base of said first processor.

9. In a distributed control system having at least one shared resource and comprising a plurality of processors, a hunting arrangement for selecting an available shared resource, comprising:

means in each of said processors for storing a local data base comprising availability data for said at least one shared resource and operative under program control for slecting an available shared resource;

common data communication means connected to each of said processors;

means in each of said processors, responsive to said means for storing and selecting, for generating and broadcasting over said common data communication means to others of said processors message comprising an identity of said selected available shared resource; and

means in each of said processors responsive to receipt of said message for altering said local data base of each of said processors to indicate that said selected available shared resource is not available.

10. In a distributed control system having at least one shared resource and comprising a plurality of processors, a hunting arrangement for selecting an available shared resource, comprising:

means in each of said processor for storing a local data base comprising availability data for said at least one shared resource and oeprative under program control for selecting an availale shared resource as a candidate resource without changing the local data base of that processor to indicate that said candidate resource is not available;

common data communication means connected to each of said processors;

means in each of said processors, responsive to said means for storing and selecting, for generating and broadcasting over said common data communication means to others of said processors a message comprising an identity of said candidate resource;

means in each of said processors responsive to receive of said message for altering said local data base of each of processors indicate that said candidate resource is not available; and

means in each of said processors, operative under program control, for recognizing that said broadcasting message has been sent by that processor and, responsive to said recognition, prior to altering the local data base of that processor, for testing whether the local data base of that processor indicates that said candidate resource is available, and for selecting said candidate resource as the selected available shared resource if said testing indicates that said candidate resource is available.

11. In a distributed control system, the hunting arrangement of claim 10 further comprising:

means in each of said processors, operative under program control, responsive to said means for recognizing, testing, and selecting, for selecting another candidate resource if said means for recognizing, testing, and selecting indicates that said candidate resource is not available.

12. In a distributed control system, the hunting arrangement of claim 11 wherein said broadcast message is also received by the processor that generated the message, and wherein said means for recognizing, testing, and selecting is responsive to receipt of said broadcast message.

13. In a distributed control telecommunication switching system having a multiplicity of ports and comprising a plurality of modules each having a processor with a local data base, each module comprising a subgroup of said multiplicity of ports, wherein a subset of said multiplicity of ports comprises a multiport group, a hunting arrangement for selecting an available port in said multiport group, comprising:

means in each of said processors for storing a local data base comprising availabiity data for said multiport group and software for controlling selection of an available port of said multiport group;

common data communication means connected to each of said processors;

means in each of said processors, responsive to said means for storing said selecting, for generating and broadcasting over said common data communication means to others of said processors a message comprising an identity of said selected port; and

means in each of said processors responsive to receipt of said message for altering said local data base of each of said processors to indicate that said selected resource is not available.

14. In a distributed control telecommunication switching system having a multiplicity of ports and comprising a plurality of modules each having a processor with a local data base, each module comprising a subgroup of said multiplicity of ports, wherein a subset of said multiplicity of ports comprises a multiport group, a hunting arrangement for selecting an available port in said multiport group, comprising:

means in each of said processors for storing a local data base comprising availability data for said ports of said multiport group and operative under program control for selecting a candidate available port from the ports of said group without changing the local data base of that processor to indicate that said candidate port is not available;

common data comnunication means connected to each of said processors;

means in each of said processors, responsive to said means for storing and selecting, for generating and broadcasting over said common data communication means to others of said processors a message comprising an identity of said candidate port;

means in each of said processors responsive to receipt of said message for altering said local data base of each of said processors to indicate that said candidate port is not available; and

means in each of said processors, operative under program control, for recognizing that said broadcast message has been sent by that processor and, responsive to said recognition, prior to altering the local data base of that processor, for testing whether the local data base of that processor indicates that said candidate port is available, and for selecting said candidate port as the selected port if said testing indicates that said candidate port is available.

15. In a distributed control telecommunication switching system, the hunting arrangement of claim 14 further comprising:

means in each of said processors, operative under program control, responsive to said means for recognizing, testing, and selecting, for selecting another candidate port if said means for recognizing, testing, and selecting indicates that said candidate port is not available.

16. In a distributed control telecommunication switching system, the hunting arrangement of claim 15 wherein said broadcast message is also received by the processor that generated the message, and wherein said means for recognizing, testing, and selecting is responsive to receipt of said broadcast message.