Ciena Corporation

Premal Desai

Neeraj Gulati

Murtuza S Attarwala

Alok Khambatkone

Sivaramakrishna Kuditipudi

Lei Fu

Wushao Wen

John Stephen Brenneman

Biao Lu

Theodore Ernest Tedijanto

Mehul Dholakia

Rakesh Kumar Sinha

Shishir Krovvidi Ramam

Michael Champlin

Ted Tedijanto

Protection and working routes are determined responsive to shared resources. The administrative weight value of a route can correspond to the physical distance associated with that route. Once the administrative weight values are assigned, that route having the lowest administrative weight value is designated the working route. The protect route is next identified by reassigning administrative weight values to the remaining routes in the network. Those routes that share resources, such as a fiber bundle or conduit, with the working route are assigned high administrative weight values, while those routes independent of the working route are assigned administrative weight values corresponding to the physical distance of each route. That route having the lowest administrative weight value after working route selection is designated the protect route. Accordingly, by assigning high administrative weight values to routes sharing resources with the working route, those resource-sharing routes are not selected as protect routes. Suitable protect routes, therefore, can be identified quickly and efficiently.

Multiple bundle identification for calculation of a network protect path responsive to shared resources

An embodiment of the invention provides a flexible bandwidth advertisement method that can reduce the number of routing updates that are sent in a network. In an embodiment of the invention, a method of reducing available bandwidth updates in a link in a communication system is provided. The method includes setting a range of threshold values. An actual available bandwidth in the link is then changed. If the actual available bandwidth changes from a first value within the range of threshold values to a second value within the range of threshold values, then a transmission of an available bandwidth update on the link is then prevented.

Reduced available bandwidth updates

An embodiment of the invention provides a method for glare resolution in a network. The method first designates a master node and a slave node. The method prevents the slave node from initially allocating a first line and a first timeslot for a first sub network connection (SNC) (SNCor SNCs. The master node allocates the first line and the first timeslot for the first SNC, and a second line and a second timeslot for a second SNC (SNCor SNCs).

Glare resolution

An embodiment of the invention provides a method and apparatus for restoring a connection in a network. The connection is typically a sub network connection (SNC). In an embodiment, a failed line in a link connecting a first node and a second node is detected, where the failed line is associated with a sub network connection (SNC). The sub network connection (SNC) is then mapped to an alternate line in the link. The first node will change cross connections in a switch fabric in the first node, while the second node will change cross connections in a switch fabric in the second node, so that both nodes can transmit data on the selected alternate line, in order to restore the SNC.

Local span mesh restoration (LSMR)

Consistent with a feature of the present invention, protection and working routes are determined by assigning administrative weight values to each route in a network. The administrative weight value of a route can correspond to the physical distance associated with that route. Once the administrative weight values are assigned, that route having the lowest administrative weight value is designated the working route. The protect route is next identified by reassigning administrative weight values to the remaining routes in the network. Those routes that share resources, such as a fiber bundle or conduit, with the working route are assigned high administrative weight values, while those routes independent of the working route are assigned administrative weight values corresponding to the physical distance of each route. That route having the lowest administrative weight value after working route selection is designated the protect route.

Multiple bundle identification for calculation of a network protect path

A method and system for allocating bandwidth in an optical communication system. During a set-up phase, a set-up message including requesting a connection is generated and includes a requested priority and requested bandwidth. When a switch receives the set-up message, the switch determines whether the available priority bandwidth for the requested priority exceeds the requested bandwidth. If the available priority bandwidth for the requested priority exceeds the requested bandwidth, the switch creates a provisional connectional which is committed to an actual connection in a subsequent connect phase. If the available priority bandwidth for the requested priority does not exceed the requested bandwidth, then the switch rejects the connection to provide a fast release.

Method, system and storage medium for allocating bandwidth in a communication network

1+1 Mesh Protection provides 1+1 protection for connections across an automatically routed mesh network, where a connection is setup automatically by using an intelligent signaling and routing protocol. 1+1 Mesh Protection can set up, tear down, and reroute both the working path and protect path across the mesh network automatically based on a specified service profile. 1+1 Mesh Protection interoperates seamlessly with traditional 1+1 protection mechanisms such as APS 1+1 protection in SONET networks.

1+1 Mesh protection

Lines within an aggregated link extending between network elements in a communications system are monitored for faults. Once a fault is detected on a particular line carrying a control channel, an alternative line is selected and control channel is transmitted on the alternative line. Once a control channel is received at a remote end on a new line, the control channel is reassigned to that line. In an alternative embodiment, the control channel is split into separate channels carrying routing and signaling information, respectively. The separate routing and signaling channels are carried by separate lines, but can be reassigned to other lines in response to a fault. Further, the routing information can be carried by multiple lines in an alternating pattern such as a round robin fashion.

Resiliency of control channels in a communications network

An embodiment of the invention is a network element including a monitor module for monitoring received network traffic on a uni-directional, first working link and detecting a failure in the first working link. A controller in communication with the monitor module is notified of a failure in the first working link. A mesh protection service (MPS) module is in communication with the controller. The MPS module transmits an MPS message signal using uni-directional communications. The MPS message signal identifies the first working link.

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San Jose, CA, United States of America

Premal Desai