Tellabs Operations, Inc.

Coriant Operations, Inc.

Jonathan B Sadler

T Benjamin Mack-Crane

Susan W Teller

Thomas J Huber

Mark Loyd Jones

Mark E Boduch

David W Jenkins

Weiying Cheng

Dale Alan Scholtens

Anoop John Mathew

Steven D Schwager

Thomas T Karjck

Dion Kwun Kit Loung

Digvijay Sharma

Ramesh Kuppusamy

Benjamin Mack T Crane

In a telecommunications/data network, it is common to have multiple recovery domains each employing its own technique for recovering a fault that may be different from a technique employed by another domain. Permitting multiple recovery domains to recover a fault without coordination among the domains can result in adverse interactions, such as rapid and repeated changes in the actions taken or 'flapping,' and repeated hits to traffic. A method and corresponding apparatus for coordinating fault recovery in a network, according to an embodiment of the present invention, notifies a first recovery domain that a second recovery domain is or is not taking action to recover a fault in the network. Coordinating the recovery efforts of the first and second recovery domains reduces fault recovery time and allows concurrent actions to be taken.

Method and apparatus for coordinating fault recovery techniques among domains

Example embodiments of the present invention relate to increasing an aggregate capacity of a network without using a centralized switch fabric. A method and corresponding apparatus in an example embodiment of the present invention relates to increasing overall aggregate capacity of a switching system. The example embodiment includes a first switching shelf having a first predetermined aggregate capacity, and multiple second switching shelves having a second predetermined aggregate capacity. The second predetermined aggregate capacity is less than the first predetermined aggregate capacity. The example embodiment increases the overall aggregate capacity as a function of connections between the first switching shelf and the multiple second switching shelves. The shelves are interconnected with interconnection links and can be configured to connect to additional shelves as the switching system grows to larger sizes. Embodiments can increase capacity while reducing cost within a network node.

Method and apparatus for increasing overall aggregate capacity of a network

Each node of a telecommunications network determines a connection type attributes available for each signal type supported by the node. Each signal type represents a different connection routing layer within the telecommunications network. Adaptation costs involved in traversing from one connection routing layer to another connection routing layer in the node are calculated. The connection type attributes and adaptation costs are included in a link state advertisement broadcasted by each node in the telecommunications network. A route calculation is performed for a desired signal to determine a route through the telecommunications network for the signal. The route calculation takes into account the various connection type attributes, availability, and adaptation costs in determining the shortest route for the signal through the telecommunications network.

Method and system for multi-layer network routing

The embodiments disclosed herein provide a mechanism for sharing protection resources in an arbitrary network topology involving pre-computing the protection resources so that data-plane-based protection can be used to activate the protection resources upon detection of a failure, thus, providing faster switching times than typical control-plane-based solutions. This is accomplished by configuring a mesh network to include, for a working path in the network, one or more protection paths with the same end nodes as the working path, where each protection path includes at least one intermediate node that is not part of the working path. The intermediate node accepts a protection request from one of the end nodes and determines whether a local resource for a protection path is available. If the local resource is available, the intermediate node forwards the protection request along the protection path, but, if the local resource is unavailable, the intermediate node notifies the end node from which the protection request originated that the protection path is unavailable.

Architecture and protection method for mesh protection of N services with M shared resources

A cost of a path may not be the only factor in searching for a path solution in a network. For example, some applications are delay sensitive and require finding a path that does not exceed a latency constraint for the entire path. Accordingly, a method and corresponding apparatus for searching for a path solution in a network is provided that identifies combinations of partial paths that satisfy an end-to-end path constraint, compares attributes of the combinations of partial paths, prunes the combinations of partial paths based on results of the comparing to identify candidate combinations of partial paths, and selects a candidate combination of partial paths as the path solution. By pruning combinations of partial paths, considerable is saved compared to exhaustive comparing of every possible combination of partial paths and scalability is achieved.

Method and apparatus for least cost routing using multiple path accumulated constraints

Optical networks occasionally experience a fault along a communications path. Service providers prefer to have an alternative communications path available to enable users to still communicate in a seamless manner. Accordingly, a method and corresponding apparatus for providing path protection for dedicated paths in an optical network is provided.

Dual fault tolerant optical networking with fast protection performance

An intelligent network planning and provisioning tool is provided. The intelligent network planning and provisioning tool includes a forecaster coupled to a network control plane. The forecaster receives an estimate of initial network resources from a user and generates a set of link costs and constraints for use by the network control plane in making routing decisions for a network. The network control plane transmits provisioning experience information, representing network traffic demands received by, and provisioning decisions made by, the network control plane, back to the forecaster. When the forecaster receives the provisioning experience from the network control plane, the forecaster generates a new set of link costs that are transmitted to the network control plane for use in making further provisioning decisions. The forecaster may optionally generate link costs, termed 'smart costs', that may be used to route traffic through the network using preferred links.

Intelligent network planning and provisioning tool

A method for managing transport node capability information includes discovering a link end of a local transport node, modelling the local transport node's capability information as a first set of information structures, discovering a neighbor transport node, establishing a control adjacency link between control elements of the local transport node and neighbor transport node, modelling the neighbor transport node's capability information as a second set of information structures, exchanging the first and second sets of information structures between the control elements and identifying potential network layer links between the local and neighbor transport nodes, based on correlations in the first and second sets of information structures.

Methods and apparatus for exchanging network connectivity and capability information

Each node of a telecommunications network determines interface point connection type attributes available for each signal type supported by the node. Each signal type represents a different connection routing layer within the telecommunications network. Adaptation costs involved in traversing from one connection routing layer to another connection routing layer in the node are calculated. The connection type attributes and adaptation costs are included in a link state advertisement broadcasted by each node in the telecommunications network. A route calculation is performed for a desired signal to determine a route through the telecommunications network for the signal. The route calculation takes into account the various connection type attributes, availability, and adaptation costs in determining the shortest route for the signal through the telecommunications network.

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Naperville, IL, United States of America

Jonathan B Sadler