Mci Communications Corporation

Mci, Inc.

Other

Worldcom, Inc.

Mark W Sees

Lee Dennis Bengston

Will L Russ

William D Croslin

Bryan J McGlade

Clinton Allen Wagner

Jasvantrai C Shah

Sridhar Alagar

Steve Sellers

Sig Harold Badt, Jr

Hal Badt

Clint Allen Wagner

Ashley Brimmage

Fred Ellefson

Tim T Chao

Lawrence Commerford

Perry Voyles

In a telecommunications network provisioned with different types of restoration processes, to ensure that the operation of one restoration process does not infringe upon other nodes that are actively executing a different restoration process, a request is sent by one of the restoration processes, under the guise of the operation system that oversees that process, to the operation system that oversees the other restoration process. The controller of the nodes that are performing the other restoration process, in receipt of the request, sends a disable restoration process message to those nodes under its control. Each of those nodes, upon receipt of the disable restoration process message, would disable the restoration process it is provisioned with so long as it is not actively engaging in that restoration process. If it is, it will continue to execute that restoration process until a safe stop point is reached, at which time it ceases that restoration process. Upon cessation of the particular restoration process, the node sends an acknowledge message to its controller, which, when in receipt of such acknowledge message from all of the nodes under its control, sends a disable acknowledged message to the controller of the first restoration process informing the latter that the nodes under its control can now be operated using the first restoration process. The above method is applicable to a telecommunications network provisioned with multiple layers of restoration processes including for example DRA, RTR and centralized restoration.

Method of coordinating the respective operations of different restoration processes

A method and system for excluding restoral routes from use in bypassing a failed component. Prior to failure of a segment, the restoration system identifies each path in the communications network. A path is a unique sequence of installations that a segment traverses. The restoration system then creates a mapping of the ports of the restoration nodes to the paths of the segments connected to each port. The restoration system then identifies for each path the set of paths that are interdependent. A pair of paths are interdependent when both paths traverse a common pair of installations. Following failure of a segment, the restoration system uses the port on which the failure was detected and uses the mapping to identify the path of the segment that failed. The restoration system then excludes each restoral route that includes a segment that has a path that is interdependent with the identified path.

Centralized method and system for excluding components from a restoral route in a communications network

To revert the topology of a network to its original or normal state after an alternate route has been found for bypassing traffic away from a malfunctioned link that has since been repaired, an Operation Support System (OSS) sends to each of the custodial sender/chooser nodes and the tandem nodes that form the alternate route respective commands to revert the operation(s) that each node had performed during distributed restoration. The OSS is able to identify the custodial nodes by the fact that those nodes perform more operations than the tandem nodes. The operations that were performed during the distributed restoration process were recorded and the thus restored topology of the network is mapped and stored. Upon receipt from the different nodes that the malfunctioned link has been repaired, the OSS sends to each of the nodes a specific command to perform the inverse of the operation(s) that that node had performed during the restoration. The custodial nodes are ordered to perform their inverse operations first so that the malfunctioned link that has since been repaired once again connects the custodial nodes. A path verification process is next performed to ensure the integrity of the newly repaired path. Once the integrity of the repaired path is confirmed, each of the tandem nodes performs the inverse of the operation it had performed during the distributed restoration to disconnect the cross connected ports within each of the tandem nodes.

System and method for reconfiguring a telecommunications network to its normal state after repair of fault

In a restoration network including a distributed restoration algorithm (DRA) enabled network of a telecommunications network, path verification messages are embedded onto traffic bearing signals entering the network and removed from the signals leaving the network. By adding path verification messages to the signals that traverse within the DRA enabled network, the integrity of any communications path that interconnects the various nodes within the restoration network are confirmed. Further, by removing the path verification messages from the signals leaving the restoration network, equipment outside the restoration network are spared of any possibility that their operations may be affected by the path verification messages.

Method and system therefor of confining path verification signals within

A method and system for initiating distributed restoration of a communications network following the failure of one or more network components. Restoration is conducted in a distributed fashion by all the restoration nodes of the network. When a restoration node detects failure of a segment connected to it, the restoration node monitors its segments for a period of time and then sends a failure message to other restoration nodes of the network indicating the number of segments connected to it that have failed. When restoration nodes receive failure messages, they compare the count of failed segments contained in the messages to a range of counts of failures for the detecting node that are locally stored on each restoration node. By this comparison, the restoration nodes can determine whether the network has quiesced to a relatively stable state following a network outage. Once the network has reached a stable state, all the restoration nodes simultaneously initiate a local restoration process.

Method for initiating a distributed restoration process

A distributed method and system for excluding segments from use in bypassing a failed component. Prior to failure of a segment, the restoration system at a central location identifies each path in the communications network. A path is a unique sequence of installations that a segment traverses. The restoration system then creates a mapping of the ports of the restoration nodes to the paths of the segments connected to each port. The restoration system then identifies for each path the set of paths that are interdependent. A pair of paths are interdependent when both paths traverse a common pair of installations. The restoration system then downloads to each restoration node the mappings for its ports along with an indication of the paths that are interdependent with the path of each segment connected to the restoration node. Following failure of a segment, the restoration node that detects the failure uses the downloaded mapping to identify the failed path and notifies the other restoration nodes of the failed path. The restoration system at each restoration node then excludes each segment that has a path that is interdependent with the failed path when implementing a restoral route.

Distributed method and system for excluding components from a restoral

To verify that a communications path restored in response to a failure to a telecommunications network is a validly restored path, each of the end nodes terminating the restored communications path sends out a message containing data that identifies that node and the ID of the access/egress port to which the STS-1 circuit forming the communications path is connected. Once the respective path verification messages are exchanged between the two end nodes of the communications path, the Operations Support System (OSS) that oversees the topology of the network retrieves those messages and compares the data contained therein with the data of the same type of messages from the same ends nodes that were stored just prior to the occurrence of the disruption to the communications path. The restored communications path is deemed to be verified if there are no differences between the path verification messages retrieved after the failure event and the path verification messages stored just prior to the failure event.

Automated path verification for shin-based restoration

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.

Dynamic restoration process for a telecommunications network

A system and method for restoring communication between at least one pair of nodes in a network. Distributed intelligence is provided by messaging between adjacent nodes in the network. The messages in combination with user-configurable timers and rules provide fault isolation, forward flooding, reverse linking and connection.

Implementation protocol for SHN-based algorithm restoration platform

A system and method for dynamically determining the physical connection topology between diverse network elements (DNEs) within a communication network. Each DNE is audited on a periodic basis to determine the arrangement, configuration, cross-connection, and alarm status of each communication port within each DNE in the communications network. A topology database is maintained with such baseline information. Each DNE is configured with at least one mismatched port. Mismatched ports are cross-connected with communication ports within DNEs so that signal mismatch alarms are generated by communication ports coupled with the mismatched ports in other DNEs. Signal mismatch alarms are collected and processed so that connectivity status may be derived based on the baseline data, expected alarms, and the receipt of such alarms or lack thereof. A topology database is continuously updated to reflect such derived information.

Dynamic network topology determination

To estimate an optimal amount of spare capacity for a network so that efficient distributed restoration of the network can take place in the event of a network failure, parameter assumptions and network design guidelines are provided to a network modeling tool to generate a desirable amount of spare links for the network. The spare links are allocated to the different nodes of the network. After a failure in the network, the result of the restoration of the network due to the failure is reported to the controller of the system. If necessary, the parameter assumptions and network design guidelines are updated and fed back to the network modeling tool for further refining the spare capacity of the network. An optimal amount of spare capacity is thus achieved by a continuous redeployment of the spare capacity output provided by the network modeling tool. Simulated failures and subsequent restorations of the network are provided to an exerciser periodically. Results from the exerciser further enhance the operations of the network modeling tool to provide an optimal amount of spare capacity for the telecommunications network.

System and method therefor of estimating optimal spare capacity for a

The present invention provides to a distributed restoration scheme a set of timers so that multiple senders and choosers can more fairly contend for the spare capacity of a telecommunications network. In particular, a preactivation timer would force a sender that had reserved excess spare capacity of the network for restoring its own failed links to release any unused spare capacity prior to the time that it terminates its operation, provided that it has found an alt-route or alt-routes for its failed link. An alarm validation timer and a hold off timer in the invention scheme further provide for respective validation and detection that a detected fault is not transient or intermittent in nature and that a restoration process is needed to find the alt-routes.

Growing community of inventors

Plano, TX, United States of America

Mark W Sees