Cisco Technology, Inc.

Vahid Parsi

Ali Najib Saleh

Zareh Baghdasarian

H Michael Zadikian

Haig Michael Zadikian

John Conlon Adler

Robert A Hall

A method and apparatus for centralized control of a network is described. The network includes a number of nodes. The method includes creating a database and storing the database on a master node of the network. The database contains topology information regarding a topology of the network. Each of the nodes is coupled to at least one other of the nodes, with the master node being one of the nodes.

Method for routing information over a network employing centralized control

A method and system is provided to reduce the time to restore links in a communication system. The method and system employ a preplanned backbone zone to eliminate downtime searches for alternate paths. Efficient use of restoration techniques assures that inter-zone routes are properly allocated. Alternate paths are chosen by calculating shortest paths from a root node to a target node. The shortest paths are placed in a table for lookup whenever a communication failure occurs. Considerations as to cost and length are taken into account in determining the alternative routes.

Method and apparatus for inter-zone restoration

A method for restoring a virtual path, provisioned between a source and a target node, in a mesh zoned optical network is described. The method, in one embodiment, broadcasts or floods restore path requests in the network to expedite the identification of an alternate route and minimize the service disruption for failed virtual path. The flooding of requests is controlled to ensure efficient performance of the network yet guaranteeing minimum restoration time to allow critical telecommunication related traffic to flow through the network with virtually no interruption. The constant update of nodal topology by each node allows a fast identification of alternate physical path for failed virtual path.

Virtual path restoration scheme using fast dynamic mesh restoration in an optical network

A method of communicating information regarding a failure is disclosed. The method includes generating failure information. The failure affects a virtual path, which is between a first node and a second node. A first zone includes the first node, and a second zone includes the second node. The failure information can include, for example, a zone identifier and/or an action code.

Control of inter-zone/intra-zone recovery using in-band communications

A signal router, configured to receive information carried by a first signal and transmit the information on a second signal, is described. The signal router, using routing information it gathers, selects the second signal from a number of signals, with the first and the second signals differing in at least one physical characteristic. The signal router operates in a network of a number of such signal routers, and so each one of the signal routers is coupled to at least one of the other signal routers. The routing information is used to create a circuit from a first one of the signal routers to a second one of the signal routers. Once the circuit is created, the information is routed over the circuit. According to one aspect of the present invention, the signals are optical signals.

Configurable network router

A method for restoring a virtual path, provisioned between a source and a target node, in a mesh optical network is described. The method, in one embodiment, forwards a resource request in the network to identify an alternate route. Each node identifies and allocates resources for failed virtual path and the virtual path is provisioned using these resources. The constant update of nodal topology by each node may provide a fast identification of nodes with required bandwidth for failed virtual path.

Method for restoring a virtual path in an optical network using dynamic unicast

A method of operating a network is described. The network includes a number of nodes connected by a number of links. A method according to the present invention provisions a virtual path between a first and a second one of the plurality of nodes by: identifying the first and the second nodes, discovering a physical path from the first node to the second node, and establishing the virtual path. The method discovers a physical path from the first node to the second node by automatically identifying nodes forming the physical path. The method establishes the virtual path by configuring a set of connections between the nodes forming the physical path.

Protocol for the determination of network topology

A method of operating an optical network is described. The network includes a number of nodes connected by a number of links. A method according to the present invention provisions a virtual path between a first and a second one of the plurality of nodes by: identifying the first and the second nodes, discovering a physical path from the first node to the second node, and establishing the virtual path. The method discovers a physical path from the first node to the second node by automatically identifying nodes forming the physical path. The method establishes the virtual path by configuring a set of connections between the nodes forming the physical path.

Method for routing information over a network

A method is provided to allocate bandwidth from a first node to a second node in a optical network. The method begins by accepting a request from an end-user, who requests a virtual path between the first node and the second node. The first and second nodes are ones of a number of such nodes. Each one of the nodes is coupled to at least one other node by at least one of a number of optical links. The nodes and links form the optical network. The virtual path has a bandwidth requirement associated therewith. Next, the service provider determines an amount of bandwidth available between the first and the second nodes. The service provider then allocates at least a portion of the amount of bandwidth available between the first and second nodes equal to the bandwidth requirement, so long as the bandwidth requirement is not greater than the amount of bandwidth available between the first and second nodes.

Method of allocating bandwidth in an optical network

A method for restoring a virtual path, provisioned between a source and a target node, in a zoned mesh optical network is described. The method, in one embodiment, allocates a primary and a secondary physical path to the virtual path. The two physical paths are node and link disjoint. In case of a failure on one physical path, the network switches the virtual path to the other physical path. The alternate path can be shared among various virtual paths during the restoration.

Method for restoring a virtual path in an optical network using 1:N protection

A method and apparatus for restoring a virtual path are disclosed. The method includes identifying an alternate physical path and determining whether the alternate physical path is able to support the virtual path by determining whether each node of the second subset of nodes has sufficient resources necessary to support the virtual path. The virtual path is over a physical path in an optical network, and the optical network includes a number of nodes. The physical path includes a first subset of nodes of the nodes. The alternate path includes a second subset of nodes of the nodes and is between a first node and a second node of the first subset of nodes.

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Richardson, TX, United States of America

Vahid Parsi