Abstract: A method and apparatus for performing a path based quality check for a specified bit rate in a wavelength division multiplexing optical network is described. According to one embodiment of the invention, a method selects from a database one of the available paths as a currently selected path. The database stores a representation of the available paths from an access node of the optical network to other access nodes of the optical network. The method further determines a cumulative noise, cumulative chromatic dispersion, and a maximum allowable chromatic dispersion for the currently selected path. In addition, the method determines whether the currently selected path passes the path based quality check based on whether the cumulative noise is less than the maximum allowable noise at a specific bit rate and whether the chromatic dispersion is less than the maximum allowable chromatic dispersion at the specified bit rate.

Abstract: A method and apparatus for performing a path based quality check for a specified bit rate in a wavelength division multiplexing optical network is described. According to one embodiment of the invention, a method selects from a database one of the available paths as a currently selected path. The database stores a representation of the available paths from an access node of the optical network to other access nodes of the optical network. The method further determines a cumulative noise, cumulative chromatic dispersion, and a maximum allowable chromatic dispersion for the currently selected path. In addition, the method determines whether the currently selected path passes the path based quality check based on whether the cumulative noise is less than the maximum allowable noise at a specific bit rate and whether the chromatic dispersion is less than the maximum allowable chromatic dispersion at the specified bit rate.

Abstract: A method and apparatus for implementing optical network quality using bit error rate and chromatic dispersion. According to one embodiment of the invention, a method includes the provision of quality of service in a wavelength division multiplexing optical network that supports a plurality of bit rates. As part of this method, the cumulative noise and cumulative chromatic dispersion for each available path as a whole is determined, where an available path is a series of two or more nodes each connected by an optical link on which a set of wavelengths is available for establishing a lightpath. In addition, different grades of path quality are distinguished based on bit error rate (BER), where BER is based on cumulative noise and bit rate. Furthermore, a minimum path quality is required based on chromatic dispersion decibel penalty, where chromatic dispersion decibel penalty is based on cumulative chromatic dispersion and bit rate.

Abstract: A set of one or more connectivity constraints imposed on the building/maintaining of network topology databases.

Abstract: A selective distribution messaging scheme for an optical network. According to one embodiment of the invention, a wavelength division multiplexing optical network includes a number of nodes each having an optical cross connect and each having stored therein a database representing conversion free connectivity from that node to others of the nodes. In addition, each of the nodes employs a messaging scheme to propagate notification of changes in the optical network to others of the nodes to maintain their databases. The messaging scheme in each of the nodes transmits messages to only selected ones of the other nodes based at least in part on the conversion free connectivity to minimize the number of communications between nodes.

Abstract: Methods and apparatuses for multiple redundancy schemes in an optical network are described herein. In one embodiment, an exemplary method includes receiving a demand for allocating a first protection path that meets a first set of disjointness constraints with respect to a first working path according to a first protection scheme having a first priority, in response to the demand, locating a second protection path that meets a second set of disjointness constraints with respect to a second working path according to a second protection scheme having a second priority, and assigning the second protection path as a protection path to the first working path if the first priority of the first protection scheme is higher than the second priority of the second protection scheme. Other methods and apparatuses are also described.

Abstract: A source based scheme to establish communication paths in an optical network. According to one embodiment of the invention, a number of wavelength division multiplexing access nodes of an optical network employ a source based scheme to establish communication paths. Each of these access nodes stores a set of one or more network topology databases based on a set of one or more connectivity constraints.

Abstract: A method and apparatus for implementing optical network quality using bit error rate and chromatic dispersion. According to one embodiment of the invention, a method includes the provision of quality of service in a wavelength division multiplexing optical network that supports a plurality of bit rates. As part of this method, the cumulative noise and cumulative chromatic dispersion for each available path as a whole is determined, where an available path is a series of two or more nodes each connected by an optical link on which a set of wavelengths is available for establishing a lightpath. In addition, different grades of path quality are distinguished based on bit error rate (BER), where BER is based on cumulative noise and bit rate. Furthermore, a minimum path quality is required based on chromatic dispersion decibel penalty, where chromatic dispersion decibel penalty is based on cumulative chromatic dispersion and bit rate.

Abstract: Methods and apparatuses for handling multiple failures in an optical network are described herein. In one embodiment, an exemplary method includes receiving a demand for allocating a protection path that meets a set of disjointness constraints with respect to a working path, the protection path suitable to be shared with one or more other working paths, each of the working paths associated with a priority for obtaining the shared protection path, and in response to the demand, selecting a protection path that meets the set of disjointness constraints with respect to the working path and has not been shared with another working path having the same priority as the working path associated with the protection path in demand. Other methods and apparatuses are also described.

Abstract: A method and apparatus for an electrically switched optically protecting network device is described. One embodiment of the invention established pairs of optical circuits between different electrically switched optically protecting network devices acting as access nodes of an optically switched network. The network device communicates different add/drop traffic flows between externally facing ports of different electrically switched optically protecting network devices by transmitting over the optical circuit. In addition, the network device optically switches optical circuits for which the network device is an intermediate node and electrically switches packets between different ones of the network devices' externally facing ports and those of the optical circuits for which the network device is an end node. Furthermore, the network device protects the communication of traffic flows across the optical network by controlling the packet electrical switching to the pairs of optical circuits.

Abstract: Methods and apparatuses for handling multiple failures in an optical network are described herein. In one embodiment, an exemplary method includes receiving a demand for allocating a protection path that meets a set of disjointness constraints with respect to a working path, the protection path suitable to be shared with one or more other working paths, each of the working paths associated with a priority for obtaining the shared protection path, and in response to the demand, selecting a protection path that meets the set of disjointness constraints with respect to the working path and has not been shared with another working path having the same priority as the working path associated with the protection path in demand. Other methods and apparatuses are also described.

Abstract: A method and apparatus for an optical reroutable redundancy scheme. According to one embodiment of the invention, a wavelength division multiplexing optical network includes a number of nodes each having an optical cross connect and each having stored therein a database representing conversion free connectivity from that node to others of the nodes. In addition, each of the nodes employs a source based scheme with the database to provision optical circuits in real time and an optical reroutable redundancy scheme.

Abstract: A method and apparatus for an optical reroutable redundancy scheme. According to one embodiment of the invention, a wavelength division multiplexing optical network includes a number of nodes each having an optical cross connect and each having stored therein a database representing conversion free connectivity from that node to others of the nodes.

Abstract: A selective distribution messaging scheme for an optical network. According to one embodiment of the invention, a wavelength division multiplexing optical network includes a number of nodes each having an optical cross connect and each having stored therein a database representing conversion free connectivity from that node to others of the nodes. In addition, each of the nodes employs a messaging scheme to propagate notification of changes in the optical network to others of the nodes to maintain their databases. The messaging scheme in each of the nodes transmits messages to only selected ones of the other nodes based at least in part on the conversion free connectivity to minimize the number of communications between nodes.

Abstract: Quality of service based optical network topology databases are described. According to one embodiment of the invention, a set of one or more connectivity constraints that include quality of service (QoS) based criteria are applied on a physical network topology of a wave length division multiplexing optical network to divide that optical network into separate service levels. In addition, service level topologies are determined for each of the service levels.

Abstract: A source based scheme to establish communication paths in an optical network. According to one embodiment of the invention, a number of wavelength division multiplexing access nodes of an optical network employ a source based scheme to establish communication paths. Each of these access nodes stores a set of one or more network topology databases based on a set of one or more connectivity constraints.

Abstract: A method and apparatus for a network database in an optical network. According to one embodiment of the invention, a wavelength division multiplexing optical network includes optical network devices interconnected by links. These optical network devices propagate along the links connectivity request messages, initiated at each of the optical network devices acting as an access node, to discover possible end to end paths that meet a set of zero or more connectivity constraints, where an end to end path is a series of two or more of the optical network devices connected by links on which a set of wavelengths is available for establishing a lightpath. In addition, the optical network devices acting as access nodes each include a database representing available paths with costs from that access node to reachable destination nodes, where each of the paths has associated with it in the database the wavelengths available on that path.

Abstract: A set of one or more connectivity constraints imposed on the building/maintaining of network topology databases.