Lucent Technologies Inc.

Future Wei Technologies, Inc.

Huawei Technologies Co., Limited

Alcatel-lucent USA Inc.

Merlton Networks US Inc.

Yufei Wang

Paramasiviah Harshavardhana

Subrahmanyam Dravida

Bharat Tarachand Doshi

Young Lee

Zheng Wang

Leah Zhang

Wei Wang

Haomian Zheng

Tao Wan

William Carson McCormick

Murali Krishnaswamy

Zhicheng Sui

Victor Yu Liu

Oded Hauser

Frank N Hujber

Srinivasan S Ravikumar

Chuanjun Wu

Randolph Roy Kutz

Cathy Zima

Cathy Helen Zima

A method implemented by a domain controller in a network comprises transmitting, by a transmitter of the domain controller to a super controller, an update message comprising path information for one or more parallel paths having a common wavelength from a source to a destination, wherein the one or more parallel paths are free of optical impairments when the update message is transmitted to the super controller, receiving, by a receiver of the domain controller from the super controller, an initiate message comprising an identifier of a path selected from the one or more parallel paths, and provisioning, by a processor of the domain controller, the path based on a verification that the path selected by the super controller is free of optical impairments.

Controller based path estimation and path provisioning using optical impairment data

A method including determining how many optical channel (OCh) paths are available for border node pair connections; determining which of the OCh paths satisfy a preselected latency threshold; and reporting the OCh paths that satisfy the preselected latency threshold to a service coordinator.

System and method for abstracting wavelength-switched optical network traffic engineering topology in SDN control hierarchy

The present application provides a method for planning a recovery resource for resisting N-time faults and an optical transmission device, and the method includes: planning, on an optical transmission device according to preset network planning information, a recovery resource for resisting (N&#x2212;1)-time faults for preset (N&#x2212;1)-time faults, and the recovery resource for resisting (N&#x2212;1)-time faults is an optimal recovery resource corresponding to each interrupted service during the preset (N&#x2212;1)-time faults; and planning, by the optical transmission device according to the network planning information and the recovery resource for resisting (N&#x2212;1)-time faults, a recovery resource for resisting N-time faults for preset N-time faults, where the recovery resource for resisting N-time faults is a network-wide optimal recovery resource corresponding to interrupted services during the N-time faults. According to the present application, recovery resource costs can be reduced, and recovery resource planning reliability can be improved.

Method for planning recovery resource for resisting N-time faults and optical transmission device

A data traffic scheduling method that includes selecting, using a network controller, plurality of flows that traverses a network node, generating an augmented graph based on a flow rate of the plurality of flows and link capacities of the network node, computing a flow schedule for the flow using the augmented graph to minimize delay or delay variance of the flows, and outputting the flow schedule. A data traffic scheduling method that includes obtaining, using a network controller, a network topology for a network, generating an augmented graph based on the network topology, converting the augmented graph to a mixed-integer linear program, scheduling a flow in the network using the mixed-integer linear program to minimize delay or delay variance of the flow, and outputting a flow schedule.

Low jitter traffic scheduling on a packet network

A method comprising identifying a physical ring in a physical layer of a network according to a logical ring in a logical layer of the network, wherein the logical ring is formed from a plurality of nodes interconnected by a plurality of logical links, and wherein the physical ring is formed from at least the plurality of nodes interconnected by a first plurality of physical links, computing a plurality of cross cord paths across the physical ring, and mapping the logical ring onto the physical layer to provide dual physical link failure survivability by determining primary paths and secondary paths for the plurality of logical links over the physical ring and the plurality of cross cord paths such that a secondary path of a first of the plurality of logical links is non-overlapping with a primary path of a second of the plurality of logical links.

Protection against dual failures for resilient two layer networks

A method including determining, for each reachable source-destination (S-D) node pair, a maximal number of optical channel (OCh) paths available for source-destination node pair connections and determining, if a preselected latency threshold is specified, for all available OCh paths a maximal number of paths satisfying the preselected latency threshold. The available OCh paths are reported to a Multi-Domain Service coordinator (MDSC).

Traffic demands are routed across links of an information network so as to avoid congestion and allow for future traffic growth. Traffic demands from a source node to a destination node of the network are monitored, including bandwidths associated with each of the demands. For each demand, and for a given link of the network, that portion of the bandwidth associated with each traffic demand which is provided by the given link, is determined. A maximum value of link utilization among all links of the network is then determined, wherein link utilization is defined as the amount of bandwidth used by all traffic demands routed through a given link with respect to a total capacity of the link. Traffic demands are then routed across the links of the network in such a manner as to minimize the maximum value of link utilization.

Nodes for managing congestion and traffic flow by considering the minimization of link utilization values

A method and apparatus are disclosed for monitoring and signaling a path restoration using pre-computed restoration paths following a detected fault on a primary service path in a communications network. A fault occurring inside the restorable portion of a network in heterogeneous or multiple network environments can be distinguished from faults occurring outside the restorable network in accordance with the ANSI Tandem Connection Maintenance standard, T1.105.05-1994. Path restoration is activated only when a fault causing path failure occurs inside the restorable portion of the network. Each conforming node in the restorable portion of the network has the necessary monitoring, signaling and cross-connect functionality and databases to participate actively in real time restoration. Additional non-conforming network elements can be positioned between the restoration nodes without preventing path restoration. With the signaling architecture of the present invention, when an end-node detects a path failure caused by an in-network fault, it formulates a signaling message for restoring the failed path. The restoration signaling message is thereafter relayed from one node to another in the overhead or payload of signaling paths that occupy the same bandwidth that is subsequently used by the restoration path. Once a signaling message is transmitted to an adjacent node in the overhead or payload of a particular signaling path, the node that transmitted the message makes a cross-connect that replaces the signaling path with a segment of the restoration path whose set-up was requested in the transmitted signaling message.

Method and apparatus for signaling path restoration information in a mesh network

A method is provided for establishing a service connection between first and second network nodes in a WDM optical network for a plurality of network users. The method begins by receiving, from each network user, user-preferences prioritizing a plurality of decision criteria defining preferable characteristics of the service connection. Next, a prescribed algorithm is used to select a path and a channel wavelength at which information is to be conveyed over the path between the first and second nodes. The selection is based on the plurality of decision criteria as prioritized in accordance with the user-preferences. Finally, the first and second network nodes are interconnected over the selected path with the selected channel wavelength.

Wavelength and path assignment in wavelength division multiplexed ring networks

Managing congestion and traffic flow by considering the minimization of link utilization values

Managing congestion and potential traffic growth in an information network

Traffic demands are routed in a ring network by first determining an inter-ring path for a given demand, and then independently determining an intra-ring path for the demand on each of the rings in the inter-ring path. The intra-ring path provisioning is fully decoupled from the inter-ring path provisioning, such that the demand can be routed more quickly and efficiently. For example, both the routing direction and the interworking nodes for a dual ring interworking (DRI) connection can be determined independently for each of the rings of the inter-ring path. The invention may be implemented in the form of a hybrid centralized/distributed network architecture, in which a central operations system or other central controller determines the inter-ring path by applying a shortest path algorithm to a ring graph in which nodes represent rings in the network and links represent ring interconnections in the network. Ring controllers in the rings of the inter-ring path then each independently determine an intra-ring path for their corresponding rings. Although particularly well suited for use with DRI, the invention can also improve routing performance in single ring interworking (SRI) applications, as well as applications involving combinations of DRI and SRI.

Methods and apparatus for routing signals in a ring network

Distributed precomputation techniques for determining primary and/or restoration paths in an optical or electrical network. The invention provides a number of partially and fully asynchronous distributed precomputation algorithms which may be implemented, for example, by the nodes of an all-optical network, in which network links are constrained in terms of optical signal wavelength and failure isolation. A given distributed precomputation algorithm may include a first phase in which paths are allocated for capacity demands to the extent possible without resolving contentions, and a second phase in which contentions between demands for the same capacity are resolved. The first phase may implement a contention locking mechanism which locks a primary path of a given demand to prevent other demands from contending for the same capacity, and a link capacity control mechanism which involves storing a link status table at one or more nodes, the link status table listing a number of specific failures and demands which are affected by the failures. The second phase of the distributed precomputation algorithm reroutes paths previously allocated to one or more demands in order to free up capacity required for another demand, so as to optimize overall network capacity utilization.

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Holmdel, NJ, United States of America

Yufei Wang