Dynamic restoration process for a telecommunications network

• US 5,832,196 A
• Filed: 06/28/1996
• Issued: 11/03/1998
• Est. Priority Date: 06/28/1996
• Status: Expired due to Term

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: MCI Communications Corporation (Verizon Communications Inc.)
• Inventors: Croslin, William D., Sees, Mark W.
• Primary Examiner(s): Hua, Ly
• Application Number:
  US08/673,415
• Time in Patent Office: 858 Days
• Field of Search: 395/182.02, 395/200.11, 379/221, 370/400, 370/228, 370/351, 370/218
• US Class Current: 714/4.3
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04Q 3/0079 involving restoration of networks, e.g. disaster recovery, self-healing networks

Abstract

The invention is a generalized process for dynamically restoring traffic in the event of an outage in a telecommunications network. A Centralized Processing System (CPS) receives alarms from communications ports of diverse network equipment (DNE) elements. The CPS then proceeds to analyze and correlate the alarms in an effort to isolate the location of the outage. In doing so, the CPS utilizes a Network Topology database that is preferrably updated in real-time with topology data obtained directly from the DNE network. The CPS will then identify and prioritize all traffic-bearing trunks impacted by the outage. The CPS then generates and implements a restoral route for each impacted trunk by issuing appropriate reroute command to the DNEs. If a DNE responds with an indication that a command failed and that its particular restoral segment is not possible, the CPS updates Network Topology database to indicate this segment as unavailable and proceeds to generate another restoral route. After implementing a restoral route, the CPS verifies that traffic is restored. When the cause of the outage has been fixed, the CPS restores the original route.

Claims

1. A dynamic restoration process for a telecommunication network having a plurality of diverse network equipment (DNE) elements interconnected over network trunks thus forming a network topology, the process comprising the steps:

connecting inputs of a centralized processing system (CPS) to outputs from a plurality of DNEs;

maintaining a database of network topology;

sending fault alarms from DNEs to the CPS;

collecting data relating to the alarms in the CPS;

correlating the received alarms by trunk thereby isolating the location of the fault in the network;

identifying trunks impacted by the fault;

prioritizing the impacted trunks by the type of traffic carried thereby ensuring earliest restoration on important trunks;

generating optimum restoral routes for each impacted trunk;

selecting a final restoral route of impacted trunks on a prioritized basis dependent on the relative importance of the impacted trunks;

generating reconfiguration commands at the CPS in accordance with the selected restoral route;

sending the commands to selected DNEs to execute corresponding actions required for implementing the selected restoral route;

generating a response at a selected DNE indicating success or failure of the action to be executed;

determining that the actions have been successfully completed by the DNEs;

verifying that a restoral route has resulted in restored traffic; and

reversing the reconfiguration commands by the CPS to the selected DNEs for restoring an original traffic route following repair of the fault.

2. The process set forth in claim 1 further comprising the steps of:

detecting when the actions have not been successfully completed;

updating the network topology database to indicate which path of the restoral route is inoperative; and

selecting an alternate restoral route of impacted trunks on a prioritized basis excluding the inoperative path.

3. The process set forth in claim 1 wherein the step of correlating the received alarms occurs by referencing the database to determine which trunks are supported by the alarming DNEs.

4. The process set forth in claim 1 wherein the step of sending the commands to selected DNEs to execute corresponding actions required for implementing the selected restoral route is performed separately and independently of the step of generating a response at a selected DNE indicating success or failure of the action to be executed, thereby avoiding interference between sent commands and generated responses.

5. The process set forth in claim 1 wherein, prior to selecting a restoral route of impacted trunks on a prioritized basis, the database is updated to reflect an instantaneous state of the network.

6. A dynamic restoration process for a telecommunication network having a plurality of diverse network equipment (DNE) elements interconnected over network trunks thus forming a network topology, the process comprising the steps:

connecting inputs of a centralized processing system (CPS) to outputs from a plurality of DNEs;

maintaining a database of network topology;

sending fault alarms from DNEs to the CPS;

collecting data relating to the alarms in the CPS;

correlating the received alarms by trunk thereby isolating the location of the fault in the network;

identifying trunks impacted by the fault;

prioritizing the impacted trunks by the type of traffic carried thereby ensuring earliest restoration on important trunks;

generating optimum restoral routes for each impacted trunk;

selecting a final restoral route of impacted trunks on a prioritized basis dependent on the relative importance of the impacted trunks;

generating reconfiguration commands at the CPS in accordance with the selected restoral route;

sending the commands to selected DNEs to execute corresponding actions required for implementing the selected restoral route;

generating a response at a selected DNE indicating success or failure of the action to be executed;

determining that the actions have been successfully completed by the DNEs;

verifying that a restoral route has resulted in restored traffic; and

reversing the reconfiguration commands by the CPS to the selected DNEs for restoring an original traffic route following repair of the fault;

wherein the step of identifying trunks impacted by the fault further includes the steps of identifying all alarming DNE ports that support a common trunk; and

incrementally stepping inward from the ports farthest apart to a single network segment wherein the ports face the fault.

7. A dynamic restoration process for a telecommunication network having a plurality of diverse network equipment (DNE) elements interconnected over network trunks thus forming a network topology, the process comprising the steps:

connecting inputs of a centralized processing system (CPS) to outputs from a plurality of DNEs;

maintaining a database of network topology;

sending fault alarms from DNEs to the CPS;

collecting data relating to the alarms in the CPS;

correlating the received alarms by trunk thereby isolating the location of the fault in the network;

identifying trunks impacted by the fault;

prioritizing the impacted trunks by the type of traffic carried thereby ensuring earliest restoration on important trunks;

generating optimum restoral routes for each impacted trunk;

selecting a final restoral route of impacted trunks on a prioritized basis dependent on the relative importance of the impacted trunks;

generating reconfiguration commands at the CPS in accordance with the selected restoral route;

sending the commands to selected DNEs to execute corresponding actions required for implementing the selected restoral route;

generating a response at a selected DNE indicating success or failure of the action to be executed;

determining that the actions have been successfully completed by the DNEs;

verifying that a restoral route has resulted in restored traffic; and

reversing the reconfiguration commands by the CPS to the selected DNEs for restoring an original traffic route following repair of the fault;

wherein determining that the actions have been successfully completed by the DNEs further includes the steps of introducing a signal from a first secondary DNE, at one end of a trunk at the restoral route, to a second DNE at a second end of the restoral route; and

confirming, that the signal was received by the second DNE.

8. A dynamic restoration process for a telecommunication network having a plurality of diverse network equipment (DNE) elements interconnected over network trunks thus forming a network topology, the process comprising the steps:

connecting inputs of a centralized processing system (CPS) to outputs from a plurality of DNEs;

maintaining a database of network topology;

sending fault alarms from DNEs to the CPS;

collecting data relating to the alarms in the CPS;

correlating the received alarms by trunk thereby isolating the location of the fault in the network;

identifying trunks impacted by the fault;

prioritizing the impacted trunks by the type of traffic carried thereby ensuring earliest restoration on important trunks;

generating optimum restoral routes for each impacted trunk;

selecting a final restoral route of impacted trunks on a prioritized basis dependent on the relative importance of the impacted trunks;

generating reconfiguration commands at the CPS in accordance with the selected restoral route;

sending the commands to selected DNEs to execute corresponding actions required for implementing the selected restoral route;

generating a response at a selected DNE indicating success or failure of the action to be executed;

determining that the actions have been successfully completed by the DNEs;

verifying that a restoral route has resulted in restored traffic; and

reversing the reconfiguration commands by the CPS to the selected DNEs for restoring an original traffic route following repair of the fault;

wherein restoring an original traffic route following repair of the fault includes a patch-and-roll procedure further includes the of steps simultaneously transmitting signals from ports of a cross-connect of a first DNE located at a first branch that connects a first end of a restoral path with a first end of an original path;

simultaneously transmitting signals from ports of a cross-connect of a second DNE located at a second branch that connects a second end of a restoral path with a second end of an original path;

receiving signals at those ports of the cross-connects located at the first and second branches that were included in the original path; and

disengaging the ports of the cross-connects located at the first and second branches included in the restoral path.

9. A dynamic restoration process for a telecommunication network having a plurality of diverse network equipment (DNE) elements interconnected over network trunks thus forming a network topology, the process comprising the steps:

connecting inputs of a centralized processing system (CPS) to outputs from a plurality of DNEs;

maintaining a database of network topology;

sending fault alarms from DNEs to the CPS;

collecting data relating to the alarms in the CPS;

correlating the received alarms by trunk thereby isolating the location of the fault in the network, the correlating referencing the database to determine which trunks are supported by the alarming DNEs;

identifying trunks impacted by the fault by identifying all alarming DNE ports that support a common trunk;

incrementally stepping inward from the ports farthest apart to a single network segment wherein the ports face the fault;

prioritizing the impacted trunks by the type of traffic carried thereby ensuring earliest restoration on important trunks;

generating optimum restoral routes for each empacted trunk;

selecting a final restoral route of impacted trunks on a prioritized basis dependent on the relative importance of the impacted trunks;

generating reconfiguration commands at the CPS in accordance with the selected restoral route;

sending the commands to selected DNEs to execute corresponding actions required for implementing the selected restoral route;

generating a response at a selected DNE indicating success or failure of the action to be executed;

wherein the step of sending the commands to selected DNEs to execute corresponding actions required for implementing the selected restoral routes is performed separately and independently of the step of generating a response at a selected DNE indicating success or failure of the action to be executed, thereby avoiding interference between sent commands and generated responses;

detecting when the actions have not been successfully completed;

updating the network topology database to indicate which path of the restoral route is inoperative;

selecting an alternate restoral route of impacted trunks on a prioritized basis excluding the inoperative path;

determining that the actions have been successfully completed by the DNEs;

verifying that a restoral route has resulted in restored traffic; and

reversing the reconfiguration commands by the CPS to the selected DNEs for restoring an original traffic route following repair of the fault.

10. The process set forth in claim 9 wherein determining that the actions have been successfully completed by the DNEs comprises the steps:

of introducing a signal from a first secondary DNE, at one end of a trunk at the restoral route, to a second DNE at a second end of the restoral route; and

confirming, that the signal was received by the second DNE.

11. The process set forth in claim 9 wherein, prior to selecting a restoral route of impacted trunks on a prioritized basis, the database is updated to reflect an instantaneous state of the network;

and further wherein restoring an original traffic route following repair of the fault includes a patch-and-roll procedure comprising the steps;

simultaneously transmitting signals from ports of a cross-connect of a first DNE located at a first branch that connects a first end of a restoral path with a first end of an original path;

simultaneously transmitting signals from ports of a cross-connect of a second DNE located at a second branch that connects a second end of a restoral path with a second end of an original path;

receiving signals at those ports of the cross-connects located at the first and second branches that were included in the original path; and

disengaging the ports of the cross-connects located at the first and second branches included in the restoral path.