Lucent Technologies Inc.

Alcatel-lucent USA Inc.

Alcatel Lucent

Wsou Investments, LLC

Ramesh Nagarajan

Yung-Terng Wang

Muhammad A Qureshi

Bharat Tarachand Doshi

Gary Weldon Atkinson

Zbigniew M Dziong

Thomas P Chu

Song Chong

Shyam Parekh

Ahmet Akyamac

Xiang Liu

Michael L Craner

Stefan Hunsche

Steven Arvo Surek

Vinay Purohit

Tewfik Doumi

Donald David Shugard

Kamala Murti

Donald F Towsley

Walter M Pitio

Narayan Raman

Meenakshi Sharma

Carol L Janczewski

Srinivasa Prasanna

Chunxiao Chigan

David A Morano

Mark Katz

Ramachandran Ramjee

Abdo Y Alfakih

Gary W Atkinson

Ahmet A Akyamac

Walter Michael Pitio

A capability is provided for supporting a service location capability in a peer-to-peer network (P2P), such as a Chord network or other P2P network. In one embodiment, a method for locating a service within a P2P network is provided. The P2P network includes a plurality of nodes, including a target node which performs the method for locating the service within the P2P network. The target node includes a search table including a plurality of entries identifying a respective plurality of nodes of the P2P network. The method includes detecting a request to search for the service within the P2P network and initiating, toward at least one of the nodes of the search table, a service search request. The service search request is a request to identify at least one node of the P2P network that supports the service. The service search request includes information indicative of the service and a search range for use by the node receiving the service search request.

Method and apparatus for locating services within peer-to-peer networks

A method and system for efficiently provisioning a multiple service, multiple layer mesh network in a manner enabling restoration from multiple failures.

Method and system for efficient provisioning of multiple services for multiple failure restoration in multi-layer mesh networks

A method for determining a restoration path for a new service in a mesh network involves selecting between candidate restoration paths corresponding to a primary path for the new service based on the shared-risk link groups (SRLGs) associated with links in the primary path. The method includes, for each of a plurality of candidate restoration paths associated with the primary path, (1) determining whether the primary path requires any additional restoration bandwidth to be reserved on any link of the restoration path based on whether, for each link of the restoration path, the primary path is SRLG-disjoint from each other primary path that is protected by that link, (2) generating a path cost for the restoration path, where the path cost is a function of whether any additional restoration bandwidth is required; and (3) selecting the restoration path for the new service based on the path cost.

Restoration path calculation considering shared-risk link groups in mesh networks

A method and system for identifying and, optionally, managing protection resource sharing opportunities, such as within a large-scale wavelength-division multiplexing (WDM) mesh network.

Methods of protection sharing for multi-protected optical demands in large-scale WDM mesh networks

The invention comprises a method and apparatus that prevents the activation of a congestion controlling process that would otherwise be activated in response any packet loss condition. The congestion controlling process is inhibited when a congestion parameter associated indicates that the packet loss condition is not caused by congestion.

Method and apparatus for preventing activation of a congestion control process

The invention comprises a method and apparatus for determining a network connectivity in a network having a plurality of nodes. In particular, one embodiment of the method includes generating a candidate link for each of a plurality of node pairs, predicting a performance of each candidate link by evaluating an expected impact of at least one condition on each candidate link, and determining the network topology using the predicted performances of the candidate links. The performance of each candidate link may be predicted by identifying at least one condition, determining the expected impact of the at least one condition on the candidate link, and predicting the performance of the candidate link by adjusting an expected performance of the candidate link using the expected impact of the at least one condition on the candidate link.

Method and apparatus for identifying network connectivity changes in dynamic networks

A method and system for group call control in a broadband wireless network. A group call (push-to-talk) server initiates and regulates group call communication sessions. A wireless base station communicates with one or more group call participants. When a request to participate in a group call is received, it is examined to see if it contains a group call ID or other group call indicator. If not, regular call resources are allocated, if available. If so, it is determined whether another group member is attached to the base station. Group call resources are then reserved, if available, based on this determination. The resources allocated for the group call may also depend on whether the system supports multicast on the downlink to group members, or whether losing audio is supported. In some embodiments, network resources may be reallocated to support the group call.

Group call control in a wireless broadband communication network

A method for representing, in a network data structure, a minimum amount of protection bandwidth required to be reserved on each link in a mesh network, to restore service upon failure of another node or link in the network. The method includes (1) receiving a request for a new service in the network, wherein the new service is represented by a service data structure having an identification of each link and transit node in a primary path for the new service, (2) determining, using the network and service data structures, whether the new service requires additional protection bandwidth to be reserved on any link in the network, and (3) updating the network data structure if any additional protection bandwidth is determined to be needed. In one implementation the network and service data structures are vectors and the steps of determining and updating involve vector operations between these structures.

Calculation, representation, and maintenance of sharing information in mesh networks

In one embodiment, a method for setting up a flow-through mesh group (FTMG) for transmitting link-state packets (LSPs) in a network having a plurality of nodes interconnected by links. The FTMG is a combination of multiple spanning trees for the network through which LSPs are forwarded. FTMG set-up messages are received at ports of each node of the network from peer ports of linked nodes. FTMG set-up messages identify root nodes of the multiple spanning trees and the transmission modes of the peer ports. The FTMG set-up messages are used to determine (1) a root node for each spanning tree, (2) a root port on each node for each spanning tree, and (3) directionality of ports of the nodes. FTMG set-up messages are then used to determine the transmission mode of ports of the nodes and, subsequently, to update the spanning trees and transmission modes, as needed.

Automatically configuring mesh groups in data networks

In one embodiment, an automatically maintained, distributed source tree (DST) network has a plurality of fully connected internal nodes. One or more internal nodes may be connected to one or more external nodes. A first internal node synchronizes its link-state database with another internal node by sending and receiving respective Reduced Sequence Number Packet-Data-Units (PDUs) (RSNPs). An RSNP includes summary information for link-state packets (LSPs) (1) originated by the first internal node, (2) received by the first internal node from the other internal node, and (3) received from and/or originated by external nodes. If an internal link fails, then the corresponding end-nodes may recover and maintain automatic DST operation by entering either relay-mode or switch-mode operation. In relay-mode operation, an end-node tunnels packets to the other end-node via an intermediary node. In switch-mode operation, an intermediary node is selected to forward packets from one end-node to the other end-node.

Automatic maintenance of a distributed source tree (DST) network

An optical transport network comprises a number of nodes, or routers, which are coupled together via optical fibers. When a physical link comes up between a node and a neighboring node, a handshake between the node and the neighboring node recognizes the link such that the node, and the neighboring node, include it in respective link assignment tables. In addition, the node and the neighboring node negotiate a predefined sequence for assigning link resources from their respective assignment tables for satisfying future connection requests.

Minimum contention distributed wavelength assignment in optical transport networks

A method for determining primary and restoration paths for a new service in a mesh network involves (1) for each of a plurality of candidate primary/restoration path pairs for the new service, generating a path cost for each candidate pair, where the path cost for each restoration path is a function of the sum of the cost of links within the restoration path, and (2) selecting the primary and restoration paths for the new service from the plurality of candidate path pairs based on the path cost. If no sharing is possible, for low utilization links, the cost of links is a function of the administrative weight of the link, whereas for high utilization links, the link cost is a function of the inverse of the available capacity on the link. If sharing is possible, the cost is a function of the inverse of a sharing degree for the link.

Primary/restoration path calculation in mesh networks based on multiple-cost criteria

A restoration path planner that minimizes the worst-case number of cross-connections that must be performed in a network in the event of a single element failure involves a two-phase optimization. The first phase involves finding two node-disjoint paths for each service demand within a network such that the maximum link bandwidth in the network is minimized and the link bandwidths within the network are leveled. The second phase involves identifying the primary and restoration paths for each service demand within the network such that the worst-case number of cross-connections at any node within the network is minimized across all possible single-event failures. Embodiments also consider service demand-bundling that groups service demands with the same source-destination node pairs and routes them along identical primary and restoration paths, and banding, which consolidates multiple low-rate demands into a high-rate demand and consequently decreases cross-connections required in the event of a failure.

Restoration time in mesh networks

A restoration path planner minimizes cost while meeting restoration-time constraints of a network by reducing the worst-case number of cross-connections that must be performed in a network in the event of a single element failure. The planner involves optimization that identifies primary and restoration path plans for demands within the network such that the worst-case number of cross-connections at any node within the network is minimal and/or bounded. Embodiments further constrain the cost of the path plan. In one embodiment, restoration time is bounded and cost is relaxed until a solution is found. In another embodiment, the restoration time bound is relaxed to a limit while path plans and their costs are stored. These plans can later be chosen amongst for the desired balance of cost and restoration time. At least one approach to minimization of network cost involves maximizing sharing within restoration path plans.

Restoration time in networks

A technique for improving optical cross-connections comprises placing a switch in front of a number of processing units. So configured, the units are no longer dedicated to a specific link or signal. When necessary, a unit is connected/disconnected to one or more optical links by the switch to carry out any number of processing functions, such as regeneration, Raman pumping, dispersion equalization/compensation or performance monitoring. Because the units are no longer dedicated to specific links the cost of the cross-connections and the network it is a part of can be reduced.

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Somerset, NJ, United States of America

Ramesh Nagarajan