METHOD AND SYSTEM FOR PREVENTING TRAFFIC LOSS CAUSED BY WAIT-TO-RESTORE MECHANISMS IN SERVICE PROTECTION NETWORKS

• US 20120195186A1
• Filed: 01/27/2012
• Published: 08/02/2012
• Est. Priority Date: 01/31/2011
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Network Communications Incorporated (Fujitsu Limited)
• Inventors: Singh, Rajnath, Wu, Guoliang, Traylor, David
• Application Number:
  US13/360,265
• Publication Number:
  US 20120195186A1
• Time in Patent Office: Days
• US Class Current: 370/217
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

A method for preventing traffic loss includes transmitting user traffic over an automatic protection switching (“APS”) connection with revertive operation between a first switch and a second switch, determining that the working path on the APS connection has failed, moving user traffic to the protect path of the APS connection, and initiating a wait-to-restore mode including a wait-to-restore time period associated with the first switch. The method also includes, upon termination of the wait-to-restore time period of the first switch, maintaining traffic on the protect path until a message designating the working path is received on the protect path. The method further includes, upon receiving a message designating the working path, switching user traffic to the working path. The APS connection includes the protect path and the working path.

Claims

1. A method for preventing traffic loss, comprising:

transmitting user traffic over an automatic protection switching (“

APS”

) connection with revertive operation between a first switch and a second switch, the APS connection including a working path and a protect path;

determining that the working path on the APS connection has failed;

moving user traffic to the protect path of the APS connection;

initiating a wait-to-restore mode including a wait-to-restore time period associated with the first switch;

upon termination of the wait-to-restore time period of the first switch, maintaining traffic on the protect path until a message designating the working path is received on the protect path;

upon receiving a message designating the working path, switching user traffic to the working path.

2. The method of claim 1, further comprising:

during the wait-to-restore time period associated with the first switch, determining whether a message was received designating the working path;

based on the determination, terminating the wait-to-restore mode and switching user traffic to the working path before the expiration of the wait-to-restore time period of the first switch.

3. The method of claim 1, further comprising, during the wait-to-restore time period of the first switch, sending a message to the second switch designating the working path.

4. The method of claim 1, further comprising:

upon termination of the wait-to-restore time period of the first switch, entering the first switch into a state designated, according to the definitions of the G.8031 standard, as “

B”

; and

upon receiving a message designating the working path, entering the first switch into a state designated, according to the definitions of the G.8031 standard, as “

A”

.

5. The method of claim 1, wherein the second switch includes a wait-to-restore time period of different length than the wait-to-restore time period of the first switch.

6. The method of claim 1, wherein the second switch is configured to, at the end of a wait-to-restore time period of the second switch, switch user traffic to the working path.

7. An article of manufacture comprising:

a computer readable medium; and

computer-executable instructions carried on the computer readable medium, the instructions readable by a processor, the instructions, when read and executed, for causing the processor to;

transmit user traffic over an automatic protection switching (“

APS”

) connection with revertive operation between a first switch and a second switch, the APS connection including a working path and a protect path;

determine that the protect path on the APS connection has failed;

move user traffic to the protect path of the APS connection;

initiate a wait-to-restore mode including a wait-to-restore time period associated with the first switch;

upon termination of the wait-to-restore time period of the first switch, maintain traffic on the protect path until a message designating the working path is received on the protect path;

upon receiving a message designating the working path, switch user traffic to the working path.

8. The article of claim 7, wherein the instructions further cause the processor to:

during the wait-to-restore time period associated with the first switch, determine whether a message was received designating the working path;

based on the determination, terminate the wait-to-restore mode and switch user traffic to the working path before the expiration of the wait-to-restore time period of the first switch.

9. The article of claim 7, wherein the instructions further cause the processor to, during the wait-to-restore time period of the first switch, send a message to the second switch designating the working path.

10. The article of claim 7, wherein the instructions further cause the processor to:

upon termination of the wait-to-restore time period of the first switch, enter the first switch into a state designated, according to the definitions of the G.8031 standard, as “

B”

; and

upon receiving a message designating the working path, enter the first switch into a state designated, according to the definitions of the G.8031 standard, as “

A”

.

11. The article of claim 7, wherein the second switch includes a wait-to-restore time period of different length than the wait-to-restore time period of the first switch.

12. The article of claim 7, wherein the second switch is configured to, at the end of a wait-to-restore time period of the second switch, switch user traffic to the working path.

13. A system comprising:

a first switch comprising a computer readable medium and a processor coupled to the computer readable medium;

an automatic protection switching (“

APS”

) connection communicatively coupled to the first switch; and

computer-executable instructions carried on the computer readable medium, the instructions readable by the processor, the instructions, when read and executed, for causing the processor to;

transmit user traffic over an automatic protection switching (“

APS”

) connection with revertive operation between a first switch and a second switch, the APS connection including a working path and a protect path;

determine that the protect path on the APS connection has failed;

move user traffic to the protect path of the APS connection;

initiate a wait-to-restore mode including a wait-to-restore time period associated with the first switch;

upon termination of the wait-to-restore time period of the first switch, maintain traffic on the protect path until a message designating the working path is received on the protect path;

upon receiving a message designating the working path, switch user traffic to the working path.

14. The system of claim 13, wherein the instructions further cause the processor to:

during the wait-to-restore time period associated with the first switch, determine whether a message was received designating the working path;

based on the determination, terminate the wait-to-restore mode and switch user traffic to the working path before the expiration of the wait-to-restore time period of the first switch.

15. The system of claim 13, wherein the instructions further cause the processor to, during the wait-to-restore time period of the first switch, send a message to the second switch designating the working path.

16. The system of claim 13, wherein the instructions further cause the processor to:

upon termination of the wait-to-restore time period of the first switch, enter the first switch into a state designated, according to the definitions of the G.8031 standard, as “

B”

; and

upon receiving a message designating the working path, enter the first switch into a state designated, according to the definitions of the G.8031 standard, as “

A”

.

17. The system of claim 13, wherein the second switch includes a wait-to-restore time period of different length than the wait-to-restore time period of the first switch.

18. The system of claim 13, wherein the second switch is configured to, at the end of a wait-to-restore time period of the second switch, switch user traffic to the working path.