Apparatus and method for preventing network rerouting

• US 6,304,548 B1
• Filed: 05/25/2000
• Issued: 10/16/2001
• Est. Priority Date: 07/17/1997
• Status: Expired due to Term

• Current Assignee: Unify GmbH & Co. KG (Atos SE)
• Original Assignee: Siemens Information And Communication Networks, Inc. (Siemens AG)
• Inventors: Beyda, William J., Shaffer, Shmuel
• Primary Examiner(s): Hsu, Alpus H.
• Assistant Examiner(s): NGUYEN, BRIAN D
• Application Number:
  US09/579,881
• Time in Patent Office: 509 Days
• Field of Search: 370/229, 370/230, 370/231, 370/232, 370/235, 370/236, 370/237, 370/238, 370/252, 370/431, 709/235, 709/239
• US Class Current: 370/229
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13145 Rerouting upon failure
• CPC Class Codes: H04Q 2213/13146 Rerouting upon blocking/overload, rearrangement
• 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 2213/13344 Overflow
• CPC Class Codes: H04Q 2213/1338 Inter-exchange connection
• CPC Class Codes: H04Q 3/66 Traffic distributors

Abstract

A method and apparatus for preventing network rerouting when the overhead associated with the reroute operation could result in system resources being overwhelmed. The system monitors link congestion and CPU utilization that will be caused by rerouting. A comparator determines whether the amount of congestion and CPU utilization is beyond an acceptable predetermined threshold. A reroute control unit prevents rerouting if the amount of link congestion and CPU utilization exceeds the predetermined threshold.

Claims

1. A communications network rerouting method, comprising:

establishing a communications route using one or more routers, said route including one or more links for carrying data and each of said routers including a central processing unit (CPU);

monitoring data traffic using a link congestion monitor on said links and storing values representative of link congestion;

monitoring router CPU utilization and storing values representative of router CPU utilization;

determining whether said link congestion monitor values and said CPU utilization monitor values exceed predetermined threshold; and

enabling and disabling rerouting of said communications route responsive to said determining.

2. The communications network rerouting method as recited in claim 1, further comprising maintaining a table of all other routers on said communications route.

3. The communications network rerouting method as recited in claim 1, further comprising maintaining a table of all links comprising said communications route.

4. The communications network rerouting method as recited in claim 3, wherein said table further includes a list of routes accepting reroute messages.

5. The communications network rerouting method as recited in claim 3, wherein said table further includes a list of links accepting reroute messages.

6. The communications network rerouting method as recited in claim 1, further comprising transmitting a resume reroute message for enabling said rerouting.

7. The communications network rerouting method as recited in claim 1, wherein said enabling and disabling comprises transmitting a halt reroute message for disabling said rerouting.

8. A communications network rerouting method, comprising:

establishing a communications route using one or more routers, said route comprised of one or more links for carrying data and each of said routers including a CPU, said one or more routers configured to implement dynamic rerouting responsive to one or more predetermined conditions;

determining whether utilization of said CPU and congestion on said links exceed a first predetermined threshold;

enabling and disabling rerouting of said communications route responsive to said determining,

wherein said rerouting is disabled if either said CPU utilization or said link congestion exceed said first predetermined threshold.

9. A communications network rerouting method, comprising:

establishing a communications route using one or more routers, said route comprised of one or more links for carrying data and each of said routers including a CPU, said one or more routers configured to implement dynamic rerouting responsive to one or more predetermined conditions;

determining whether utilization of said CPU and congestion on said links exceed a first predetermined threshold;

enabling and disabling rerouting of said communications route responsive to said determining,

monitoring router CPU utilization;

wherein said rerouting is enabled if both said CPU utilization and said data traffic are below a second predetermined threshold.

10. A communications network rerouting method, comprising:

establishing a communications route using one or more routers, said route comprised of one or more links for carrying data and each of said routers including a CPU, said one or more routers configured to implement dynamic rerouting responsive to one or more predetermined conditions;

determining whether utilization of said CPU and congestion on said links exceed a first predetermined threshold;

enabling and disabling rerouting of said communications route responsive to said determining,

monitoring data traffic on said links;

wherein said first and said second predetermined thresholds include a predetermined level of hysteresis between said first and said second predetermined thresholds.

11. A method, comprising:

providing one or more routers for establishing a communications route, said route including one or more links for carrying data and each of said routers including a central processing unit (CPU);

providing a link congestion monitor for monitoring data traffic on said links and storing values representative of link congestion;

providing a CPU resource utilization monitor for monitoring router CPU utilization and storing values representative of router CPU utilization;

providing a comparator for determining whether said link congestion monitor values and said CPU utilization monitor values exceed predetermined thresholds; and

providing a rerouting control unit responsive to said comparator for enabling and disabling rerouting of said communications route.

12. A method, comprising:

providing one or more routers for establishing a communications route, said route comprised of one or more links for carrying data and each of said routers including a CPU, said one or more routers configured to implement dynamic rerouting responsive to one or more predetermined conditions;

providing a comparator for determining whether utilization of said CPU and congestion on said links exceed a first predetermined threshold.

providing a rerouting control unit responsive o said comparator for enabling and disabling rerouting of said communications route,

wherein said rerouting control unit will disable rerouting if either said CPU utilization or said link congestion exceed said first predetermined threshold.

13. A method, comprising:

providing one or more routers for establishing a communications route, said route comprised of one or more links for carrying data and each of said routers including a CPU, said one or more routers configured to implement dynamic rerouting responsive to one or more predetermined conditions;

providing a comparator for determining whether utilization of said CPU and congestion on said links exceed a first predetermined threshold;

providing a rerouting control unit responsive to said comparator for enabling and disabling rerouting of said communications route,

providing a CPU resource utilization monitor for monitoring router CPU utilization;

wherein said rerouting control unit will enable rerouting if both said CPU utilization and said data traffic are below a second predetermined threshold.

14. A method, comprising:

providing one or more routers for establishing a communications route, said route comprised of one or more links for carrying data and each of said routers including a CPU, said one or more routers configured to implement dynamic rerouting responsive to one or more predetermined conditions;

providing a comparator for determining whether utilization of said CPU and congestion on said links exceed a first predetermined threshold;

providing a rerouting control unit responsive to said comparator for enabling and disabling rerouting of said communications route,

providing a link congestion monitor for monitoring data traffic on said links;

wherein said first and said second predetermined thresholds include a predetermined level of hysteresis between said first and said second predetermined thresholds.