Abstract: A system and method for of pre-provisioning recovery paths in a mesh network including creating i) a working path between a head end NE and a tail end NE of the mesh network and ii) a recovery path between the head end NE and the tail end NE, wherein the working path and the recovery path include one or more intermediate NEs; provisioning the working path in an activated state, including establishing cross connects of each of the NEs of the working path; provisioning the recovery path in a pending state, including establishing cross connects of each of the NEs of the recovery path; after provisioning the recovery path, detecting a failure along the working path, and in response, allocating and reserving link resources along the recovery path; and activating, by the NEs along the recovery path, cross connects of the recovery path into respective hardware associated with the NEs.

Abstract: A system and method for of pre-provisioning recovery paths in a mesh network including creating i) a working path between a head end NE and a tail end NE of the mesh network and ii) a recovery path between the head end NE and the tail end NE, wherein the working path and the recovery path include one or more intermediate NEs; provisioning the working path in an activated state, including establishing cross connects of each of the NEs of the working path; provisioning the recovery path in a pending state, including establishing cross connects of each of the NEs of the recovery path; after provisioning the recovery path, detecting a failure along the working path, and in response, allocating and reserving link resources along the recovery path; and activating, by the NEs along the recovery path, cross connects of the recovery path into respective hardware associated with the NEs.

Abstract: A method may include: (i) in response to clearing of a fault on a working path of a protection switching group to which a first network element is interfaced: (a) transitioning, by the first network element, its state to a first state in which a protection path of the protection switching group is active; and (b) initiating, by the first network element, a wait to restore timer, the wait to restore timer having a duration such that upon expiration of the timer, the first network element is configured to switch the working path to active; and (ii) in response to receiving a message from a second network element interfaced to the protection switching group indicating that a failure has occurred on the working path: (a) maintaining, by the first network element, its state in the first state; and (b) continuing, by the first network element, the wait to restore timer.

Abstract: In one embodiment, a method for telecommunications includes determining the operational state of a first network switch, determining the operational state of a second network switch, determining the existence of an actionable condition, accessing information on the first switch, and changing the operational state of the first switch. The second network switch is coupled to the first network switch by a protected path. Determining the actionable condition and changing the operational state use references to the operational state of the first network switch, the operational state of the second network switch, and the actionable condition.

Abstract: A method may include: (i) in response to clearing of a fault on a working path of a protection switching group to which a first network element is interfaced: (a) transitioning, by the first network element, its state to a first state in which a protection path of the protection switching group is active; and (b) initiating, by the first network element, a wait to restore timer, the wait to restore timer having a duration such that upon expiration of the timer, the first network element is configured to switch the working path to active; and (ii) in response to receiving a message from a second network element interfaced to the protection switching group indicating that a failure has occurred on the working path: (a) maintaining, by the first network element, its state in the first state; and (b) continuing, by the first network element, the wait to restore timer.

Abstract: Instead of alternatively utilizing only one fabric or the other fabric of a redundant pair, both fabrics simultaneously transmit duplicate information, such that each packet forwarding module (PFM) receives the output of both fabrics simultaneously. In real time, an internal optics module (IOM) analyzes each information chunk coming out of a working zero switch fabric; simultaneously examines a parallel output of a working one duplicate switch fabric; and compares on a chunk-by-chunk basis the validity of each and every chunk from both switch fabrics. The IOM does this by examining forward error correction (FEC) check symbols encapsulated into each chunk. FEC check symbols allow correcting a predetermined number of bit errors within a chunk. If the chunk cannot be corrected, then the IOM provides indication to all PFMs downstream that the chunk is defective. Under such conditions, the PFMs select a chunk from the non-defective switch fabric.

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.

Abstract: A method for solving communication failure includes transmitting user traffic over an automatic protection switching (“APS”) connection between a near network node and a far network node, determining that a protect path on the APS connection has failed, sending a message to the far network node that the protect path has failed, and switching user traffic to the working path at the near network node.

Abstract: Instead of alternatively utilizing only one fabric or the other fabric of a redundant pair, both fabrics simultaneously transmit duplicate information, such that each packet forwarding module (PFM) receives the output of both fabrics simultaneously. In real time, an internal optics module (IOM) analyzes each information chunk coming out of a working zero switch fabric; simultaneously examines a parallel output of a working one duplicate switch fabric; and compares on a chunk-by-chunk basis the validity of each and every chunk from both switch fabrics. The IOM does this by examining forward error correction (FEC) check symbols encapsulated into each chunk. FEC check symbols allow correcting a predetermined number of bit errors within a chunk. If the chunk cannot be corrected, then the IOM provides indication to all PFMs downstream that the chunk is defective. Under such conditions, the PFMs select a chunk from the non-defective switch fabric.

Abstract: Instead of alternatively utilizing only one fabric or the other fabric of a redundant pair, both fabrics simultaneously transmit duplicate information, such that each packet forwarding module (PFM) receives the output of both fabrics simultaneously. In real time, an internal optics module (IOM) analyzes each information chunk coming out of a working zero switch fabric; simultaneously examines a parallel output of a working one duplicate switch fabric; and compares on a chunk-by-chunk basis the validity of each and every chunk from both switch fabrics. The IOM does this by examining forward error correction (FEC) check symbols encapsulated into each chunk. FEC check symbols allow correcting a predetermined number of bit errors within a chunk. If the chunk cannot be corrected, then the IOM provides indication to all PFMs downstream that the chunk is defective. Under such conditions, the PFMs select a chunk from the non-defective switch fabric.

Abstract: Router line cards are partitioned, separating packet forwarding from external or internal interfaces and enabling multiple line cards to access any set of external or internal data paths. Any failed working line card can be switchably replaced by another line card. In particular, a serial bus structure on the interface side interconnects any interface port within a protection group with a protect line card for that group. Incremental capacity allows the protect line card to perform packet forward functions. Logical mapping of line card addressing and identification provides locally managed protection switching of a line card that is transparent to other router line cards and to all peer routers. One-for-N protection ratios, where N is some integer greater than two, can be achieved economically, yet provide sufficient capacity with acceptable protection switch time under 100 milliseconds.