Nortel Networks Corporation

Ciena Corporation

Evert De Boer

Peter William Phelps

David Charles Steele

Richard Trudel

Robert Caporuscio

Louis Rene Pare

Stephen Wilson

Louis-Rene Pare

Darek Robert Skalecki

Malcolm Betts

James A Shields

Joseph Olajubu

Jean-Pierre Coupal

Darryl C Ryan

Mark Gibbon

Louis R Par&eacute;

A call setup and restoration schema is disclosed for providing an improved priority-based call setup and restoration schema in an optical communications system, allowing higher priority connections access to bandwidth by user-definable parameters. The call setup and restoration schema includes allowing higher priority connections to claim the resources of lower priority connections, and restoring them when bandwidth is available, or bumping another, even lower priority, connections. This aids in providing access to bandwidth by high priority services and in preventing outages or connection delays for high priority connections.

Method and apparatus for priority call setup and restoration in an optical communications system

A data communication apparatus having a plurality of working ports for exchanging data traffic with a network element and at least one protection port. The communication apparatus also has a protection switching functional element to switch data traffic from a failed working port to the at least one protection port. The protection switching functional element is capable to acquire either one of a first mode of operation and a second mode of operation. The first mode of operation is an 1:Q mode using a single protection port where Q is the number of working ports and Q is equal or greater than 1. The second mode of operation is an M:N mode where M is the number of protection ports and N is the number of working ports, where M and N are greater than 1.

Data communication apparatus with a dual mode protection switching system

A node within a mesh network includes an Optical Connection Controller (OCC) and a network element. When a connection path within the mesh network is required, an OCC determines if a particular connection path requires a network element to operate as a virtual gateway to separate the mesh network into separate protection domains for that particular connection path. A connection path might require separate protection domains in cases in which the number of network elements and/or repeater/amplifier components for a particular connection path is greater than a threshold, the total length of links for the connection path is above a threshold and/or another factor that could cause the recovery time for the connection path to increase beyond an acceptable threshold level. If the OCC determines that one or more virtual gateways are required for a particular connection path, the OCC selects an appropriate network element within the network to operate as a virtual gateway for that particular connection path. Finally, the OCC assigns network elements and links to establish working and protection paths between the source network element and the virtual gateway and between the virtual gateway and the destination network element. This set-up can ensure that each connection path will have a recovery time after a failure within an acceptable range.

Apparatus and method for establishment and protection of connections within mesh networks

A method and corresponding network element configuration for delivering communications services between first and second survivable rings, each comprising a respective plurality of network elements, at least two of which are common to both rings. For each particular service, one of the common network elements is designated as a primary gateway node and another as a secondary gateway node. A primary inter-ring connection is established for the particular service by a switch at the primary gateway node, but no inter-ring connection is established at the secondary gateway node. The secondary gateway node comprises a controller for monitoring the status of the primary gateway node and establishing a new inter-ring connection for delivery of the service upon detecting a failure of the primary gateway node. This provides survivable inter-ring traffic which is bandwidth-efficient and with a low switching delay.

Method and apparatus for ensuring survivability of inter-ring traffic

A method and corresponding network element configuration for delivering communications services between first and second survivable rings, each comprising a respective plurality of network elements, at least two of which are common to both rings. For each particular service, one of the common network elements is designated as a primary gateway node and another as a secondary gateway node. A primary inter-ring connection is established for the particular service by a switch at the primary gateway node, but no inter-ring connection is established at the secondary gateway node. The secondary gateway node comprises a controller for monitoring the status of the primary gateway node and establishing a new inter-ring connection for delivery of said service upon detecting a failure of the primary gateway node. This provides survivable inter-ring traffic which is bandwidth-efficient and with a low switching delay.

The present invention relates to a local node for use in a synchronous optical network ring. The local node includes a group of working transmission lines and a protection line, for connecting to a remote node. The local node further includes a control unit for monitoring the working transmission lines and, upon detection of a data transmission impairment over a particular working transmission line, invoking a protection switch event causing re-routing of optical signals from the particular working transmission line to the protection line. Should the control unit detect simultaneous data transmission impairments over two or more working transmission lines, the control unit will choose to protect a particular working transmission line on the basis of a user-defined priority scheme.

Method and apparatus for providing a more efficient use of the total bandwidth capacity in a synchronous optical network

The matched nodes provide protection for a failure in the connection between two bidirectional line switched rings. They use a secondary path in case of a primary path failure. The secondary path is set aside in either the working or protection bandwidth of the rings, thus wasting resources. The invention uses a dedicated secondary path between the primary and secondary nodes. With the invention, no ring protection mechanisms are compromised and the ring bandwidth is not wasted. Middle nodes also realize full add/drop capabilities.

Optical ring protection having matched nodes and alternate secondary path

The matched nodes provide protection for a failure in the connection between two bidirectional line switched rings. They use a secondary path in case of a primary path failure. The secondary path is set aside in either the working or protection bandwidth of the rings, thus wasting resources. The invention uses inter-ring protection mechanisms which do away with a specifically set aside secondary path between the primary and secondary nodes.

Growing community of inventors

Nepean, Canada

Evert De Boer