Ciena Corporation

Nortel Networks Corporation

Rockstar Consortium US LP

Northern Telecom Limited

Rpx Clearinghouse LLC

Darek Robert Skalecki

Gerard Leo Swinkels

Peter J Ashwood-Smith

Evelyne Roch

Jean-Pierre Coupal

Donald Wayne Fedyk

Peter Ashwood Smith

Stephen Daniel Shew

Gerald Smallegange

Nigel Lawrence Bragg

David Allan

Marc Holness

David Miedema

Anurag Prakash

Mohit Chhillar

Donald Fedyk

Steven Arvo Surek

Himanshu Shah

Piyush Sharma

Jatin Sareen

Waseem Reyaz Khan

Areef Reza

Evert De Boer

Ahmed Reza

Michael Aalders

Amal Karboubi

Sandra S Ballarte

Chris Wallace

Paul P Beaubien

Evert Deboer

Manuel Damas

Antonela Paraschiv

Ewart Tempest

Gary Swinkels

Jean Pierre Coupal

Ewert Tempest

Qingwen Hu

Ramanjit Walia

Yair Matas

James A Sheilds

Mark Gibbon

Gary McKenna

Peter Trobridge

Donald W Fedyk

Variable preemption for label-switched paths (LSP) tunnels includes provisioning a label-switched path (LSP) tunnel at a first bandwidth with a first priority value; and provisioning one or more different priority values at one or more of (1) corresponding one or more bandwidths such that a current priority value of the LSP tunnel is set based on a current bandwidth value of the LSP tunnel and (2) redial failure attempts such that the current priority value of the LSP tunnel is set based on a number of the redial failure attempts. The priority values can include one of a Setup Priority, a Holding Priority, and a combination thereof. The one of the Setup Priority, the Holding Priority, and the combination thereof can be based on RFC 3209.

Variable preemption for LSP tunnels

Systems and methods for Segment Routing (SR) Traffic Engineering (SR-TE) in a network include receiving link utilization measurements at a Label Edge Router (LER) with the link utilization measurements flooded by one or more Label Switch Routers (LSRs); and, responsive to one or more of detecting congestion and underutilization on one or more links associated with an SR tunnel at the LER based on the received link utilization measurements, performing one or more actions at the LER to one or more of alleviate the congestion and re-optimize the underutilization. A state of the SR tunnel is maintained only at the LER through a label stack assigned at the LER, and the label stack includes one or more of a node Segment ID (SID) and an adjacency SID.

Segment routing traffic engineering based on link utilization

Systems and methods provide congruent bidirectional Segment Routing (SR) tunnels, namely congruent and fate-shared traffic forwarding for bidirectional SR tunnels. A bidirectional SR tunnel, as described herein, includes two unidirectional SR tunnels where the forward and reverse traffic directions follow the same path through the network when forwarded based on prefix and adjacency Segment Identifiers (SIDs). The term 'congruent' is used herein to refer to the fact that the two unidirectional SR tunnels, i.e., the forward and reverse traffic directions, follow the same path through the network but in opposite directions. The guarantee of congruency is based on modification of the Segment Identifier (SID) configuration at the source nodes of each tunnel. Accordingly, the present disclosure maintains compatibility with existing Segment Routing configurations with the modifications solely at the source nodes.

Congruent bidirectional segment routing tunnels

Systems and methods for permitted network risks in diverse route determinations introduce the concept of permitted network risks which are risks that may be present in a disjoint path calculation. This removes the binary logic in conventional shared risk path determination, i.e., either exclude or include. With the present disclosure, a network risk may be excluded (must never use) or shared (may use if needed). In an embodiment, if a route for a backup tunnel or path excluding all network risks is not possible, then a route for the backup tunnel or path may be found excluding some network risks of the primary tunnel or path except specified network risks that are determined/specified as permitted network risks. Such permitted network risks can be explicitly specified by a network operator or implicitly determined based on a category (e.g., node and/or equipment may be shared network risks whereas links may not).

Permitted network risks in diverse route determinations

A method, node, and network for reduced link bandwidth updates from a first node and a second node forming a link in a network includes, responsive to establishment or release of one or more connections on the link, flooding an update related thereto from only a master node that is one of the first node and the second node; responsive to a link failure associated with the link, flooding an update related thereto from both the first node and the second node; and, responsive to a change in parameters associated with the link, flooding an update related thereto from both the first node and the second node. The flooding can be part of a control plane associated with the network and/or to a Software Defined Networking (SDN) controller.

Reduced link bandwidth update systems and methods for improved scalability, efficiency, and performance

Systems and methods for dynamic adjustment of a connection's priority in a network include configuring the connection with a dynamic priority and setting a current priority based on one or more factors, wherein the connection is a Layer 0 connection, a Layer 1 connection, and a combination thereof; detecting an event in the network requiring a change to the current priority, wherein the event changes the one or more factors; and causing a change in the current priority of the connection based on the event.

Dynamic adjustment of connection priority in networks

Systems and methods for efficient prioritized restoration of services implemented in a node in a network utilizing a control plane include releasing higher priority services affected by a fault on a link adjacent to the node immediately via control plane signaling such that the higher priority services mesh restore; tracking mesh restoration of the released higher priority services; and releasing lower priority services based on the tracking, subsequent to the mesh restoration of the higher priority services, wherein the higher priority services and the lower priority services comprise one or more of Optical Transport Network (OTN) connections, Dense Wavelength Division Multiplexing (DWDM) connections, and Multiprotocol Label Switching (MPLS) connections.

Efficient prioritized restoration of services in a control plane-based optical network

Systems and methods of path computation using an efficient shared risk group representation include representing a plurality of network risks in a network with a bit vector where each network risk is represented as a single bit in the bit vector; computing a pair of paths through the network; and determining diversity of the pair of paths based on a comparison of associated bit vectors for each of the pair of paths. The bit vector can include M-bits with an N-bit Group Identifier and P-bits with each of the P-bits representing a unique risk of the plurality of network risks, wherein M, N, and P are integers and N+P=M.

Efficient shared risk group representation as a bit vector

A method for managing network connections may include identifying a network failure within a network comprising various network elements. The method may include selecting, in response to identifying the network failure and for the network elements, a subset of nodal maps from various nodal maps. The nodal maps may be stored on the network elements. The subset of nodal maps may describe various cross-connections of the nodal maps within a first end-to-end connection in the network. The method may include transmitting, in response to selecting the subset of nodal maps, various activation requests to trigger the network elements to implement the subset of nodal maps.

System and method for managing network connections

Systems and methods for efficient prioritized restoration of services implemented in a node in a network utilizing a control plane include, responsive to detecting a fault on a link adjacent to the node, releasing higher priority services affected by the fault immediately via control plane signaling such that the higher priority services mesh restore; maintaining a list of the released higher priority services; tracking mesh restoration of the released higher priority services; and releasing lower priority services based on the tracking, subsequent to the immediate mesh restoration of the higher priority services.

A method, implemented in a node in a network, for a preemptible established backup path for a mesh restorable service includes, responsive to a new service request for the mesh restorable service with the preemptible established backup path, establishing a primary path designated as a current path for the mesh restorable service at a designated priority; establishing a backup path for the mesh restorable service at a lower priority than the designated priority, subject to bandwidth availability in the network; and responsive to a fault affecting the primary path, switching to the backup path and raising a priority of the backup path to the designated priority.

Mesh restorable service systems and methods with preemptible established backup paths

A method for operating an optical network (ON) using a control plane (CP), including: identifying, by the CP, a failure of a client facility connecting a network element of the ON and a client device; and terminating, by the CP and in response to identifying the failure, an optical connection through the ON for the client device.

Optical network connection termination on client facility failure

A method in a network utilizing a distributed connection-oriented control plane includes signaling a first path for a first connection from a first source node; storing call information for the first connection at any intermediate nodes in the first path; signaling a second path for a second connection from a second source node; checking at any intermediate nodes in the second path if there is absolute route diversity between the first connection and the second connection responsive to a requirement therein; and responsive to detecting a diversity violation at an intermediate node of the any intermediate nodes in the second path, signaling a crankback to the second source node with the call information for the first connection included therein; and recomputing the second path exclusive of the first path based on the call information responsive to receiving the crankback. A network and node are also described.

Systems and methods for diverse connection signaling from disparate source nodes in distributed connection-oriented networks

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Nepean, Canada

Darek Robert Skalecki