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