Abstract: Network applications rely on ever-increasing diverse and complex transport service mechanisms. A transport service between points in a network often traverses multiple technologies involving numerous containments and adaptations. A network event affecting the transport service may occur in any number of elements supporting the transport service, resulting in a myriad of alarms. Prior techniques for suppressing alarms involving complex network information models and coding logic to reduce the number of alarms presented, but require additional steps before the network event can be troubleshot and resolved. In contrast, the provided alarm correlation technique presents a highly structured and comprehensive visual presentation depicting the network event affecting the transport service in terms of the supporting elements affected by the network event.

Abstract: Methods and apparatuses are disclosed for configuring a Provider Backbone Bridge (PBB) interface within Virtual Private LAN Service using Multi-Protocol Border Gateway Protocol (MP-BGP). Previously, the only ways to enable PBB interfaces for transmission were by learning, which poses security and scalability concerns due to flooding, or by manual configuration, which is impractical for large networks. Embodiments of the present invention enable custom topologies to be built in a controlled manner, which has not previously been possible for PBB over VPLS. By using MP-BGP messages to exchange PBB interface information between nodes, peering relationships are established, and communities may be built with any desired topology. Previously, PBB has only been used as a connectionless bridge; embodiments of the present invention use PBB as a connection between edge nodes. Network designers are provided increased flexibility, and security and congestion are improved, benefiting end users.

Abstract: An embodiment of the invention discloses phase shifting a second clock signal by a phase increment with respect to a first clock signal, where the first clock signal and the second clock signal have the same periods. The first clock signal is sampled with the second clock signal, and the output of the sample indicates whether the sample of the first clock signal is at a logic one state or a logic zero state. A count of logic one samples is incremented if the sample of the first clock signal is at a logic one state. The process of phase shifting the second clock signal and sampling the first clock signal is repetitively performed to a maximum number of samples.

Abstract: A method of managing a signal over a symbol period includes supplying samples of the signal at beginning and end portions of the symbol period. The method further includes suppressing the supply of samples of the signal at a middle portion of the symbol period.

Abstract: Due to demand for more network bandwidth, a need for multi-user optical network topologies has, and will continue to, increase. A method or corresponding apparatus in embodiments of the present invention provide for an availability determination tool for determining and displaying wavelength and subrate availabilities within a network. Benefits of embodiments of a tool include allowing a user to identify the availability and capacity of any wavelength on any network, via an interactive graphical user interface, such as by using three-dimensional representations. In one embodiment, the disclosed availability determination tool allows users to locate and view any combination of available wavelengths between nodes in an optical network topology, and generate graphical and tabular reports of the availability in order to maintain an efficient and organized method or apparatus for determining and controlling wavelengths in a network.

Abstract: Optical networks occasionally experience a fault along a communications path. Service providers prefer to have an alternative communications path available to enable users to still communicate in a seamless manner. Accordingly, a method and corresponding apparatus for providing path protection for dedicated paths in an optical network is provided.

Abstract: Current approaches for determining and identifying whether a correct length of fiber cable is installed between network elements configured to communicate using specific lengths of cable require manual inspection. Such manual inspection may include the use of markers used for visual inspection of cables matching corresponding network elements. An embodiment of the present invention utilizes identifiers unique to cables of various lengths to determine whether a correct length of cable has been installed. Further, embodiments of the present invention determine whether the unique identifier is received by a network device according to a channel mapping corresponding to a unique physical mapping associated with cables of various lengths. The use of the identifiers and channel mappings enable automatic discovery of lengths of cable that are installed between network devices.

Abstract: Optical networks are increasingly employing optical network nodes having multiple interfaces to allow a node to direct optical signals received at any interface to any other interface connected to the node. Constructing a larger wavelength selective switching (WSS) module used in such a node can be complex and expensive. A method an apparatus for constructing a large WSS using parallelism is provided. In example embodiments, a larger WSS may include multiple parallel non-cascaded smaller WSSs and an optical coupler configured to optically couple the multiple parallel, non-cascaded smaller WSSs. This technique may be used to construct both N×1 and 1×N WSSs. Because the technique employs multiple parallel, non-cascaded WSSs, all inputs of a larger N×1 WSS and all outputs of a larger 1×N WSS are available receive or transmit external signals rather than being rather than being unavailable due to, for example, cascading smaller WSS devices together.

Abstract: An optical ring network has one or more working wavelengths and multiple protection wavelengths adapted to support the working wavelength(s). Routing tables may be used in network nodes to assign traffic of a failed working wavelength to a protection wavelength. The protection technique may be applied to networks employing, for example, Dense Wave Division Multiplexing (DWDM).

Abstract: A channel in a multiple carrier communication system is equalized by computing a desired spectral response, shortening the impulse response of the channel so that a significant part of an energy of the impulse response is confined to a region that is shorter than a target length and filtering the signal based on the desired spectral response. A multiple carrier communication system may include a primary impulse shortening filter that receives an output signal of an analog to digital converter and accepts coefficients. A secondary impulse shortening filter may receive the output signal of the analog to digital converter, output an output signal, and pass coefficients to the primary impulse shortening filter. A reference signal generator may output a reference signal. A comparator may compare the output signal and the reference signal and output a resulting error signal. An adaptive processor may compute coefficients for the secondary impulse shortening filter based on the error signal.

Abstract: An apparatus and method for managing and characterizing clock domains in multi-domain networks are disclosed. A process of clock domain management is capable of receiving a data packet or data stream traveling across CES circuit. Upon obtaining a clock domain hierarchy stored in a storage location, the process identifies a clock frequency in the clock domain hierarchy in accordance with the CES circuit. The clock domain hierarchy, in one embodiment, is a searchable database containing information relating to clock domains. The clock frequency is subsequently assigned to a packet processing unit for data processing.

Abstract: An intelligent network planning and provisioning tool is provided. The intelligent network planning and provisioning tool includes a forecaster coupled to a network control plane. The forecaster receives an estimate of initial network resources from a user and generates a set of link costs and constraints for use by the network control plane in making routing decisions for a network. The network control plane transmits provisioning experience information, representing network traffic demands received by, and provisioning decisions made by, the network control plane, back to the forecaster. When the forecaster receives the provisioning experience from the network control plane, the forecaster generates a new set of link costs that are transmitted to the network control plane for use in making further provisioning decisions. The forecaster may optionally generate link costs, termed “smart costs”, that may be used to route traffic through the network using preferred links.

Abstract: Small form-factor pluggable (SFP) ports are often employed in telecommunications hardware to take advantage of their lower profile and to provide connections to other network elements. The use of SFP ports has increased the density of ports possible for a given circuit board size, but this increase has previously meant that individual ports are difficult to access. Also, identification of those ports is frustrated by a lack of free space to place labeling. Example embodiments of the present invention address these issues by placing a divider plate between columns of SFP ports that provides surface area adjacent to the SFP ports for affixing labeling. The divider plate is offset from the SFP ports to allow access when the plate is installed. As a result, hardware employing embodiments of the present invention can achieve a higher density of SFP ports with ease of access by personnel assembling or servicing the hardware.

Abstract: A system, apparatus, method, and computer-readable medium for coded-domain echo cancellation. The method includes receiving a signal including at least one packet, and replacing the at least one packet with a replacement packet. In one example, the replacement packet is a comfort noise packet (such as a SID_UPDATE packet) or a NO_DATA packet. In an example embodiment, the at least one packet included in the signal includes one or more comfort noise packets, and, prior to the replacing, the one or more comfort noise packet(s) are stored in a buffer. In another example, prior to the replacing, the at least one packet is compared to a reference packet to determine whether the at least one packet is an echo packet. The packet, in one example, is encoded based on an adaptive multi-rate (AMR) (e.g., AMR-NB or AMR-WB) codec.

Abstract: Increasing data rates in next-generation optical networks requires a change in the type of optical modulation used to encode optical signals carried by the optical networks. Different types of optical modulation incur different optical impairments, which may degrade the fidelity of the optical signals by reducing the optical signal-to-noise ratio (OSNR). A method or corresponding apparatus in an example embodiment of the present invention provides a planning tool for deploying an optical network in a manner based on the optical modulation that reduces the cost and complexity of the deployed network. In one embodiment, the disclosed planning tool may adjust a model of the optical network to be deployed by changing the topology and/or the number and/or type of optical network elements in response to optical impairments for a given optical modulation.

Abstract: A method for planning a network having a plurality of nodes. The method may include determining all possible rings in the network satisfying a predetermined condition and calculating a utilization score for each possible ring based on a combination of predetermined selection criteria. The method may include selecting the possible ring with the highest utilization score and determining whether there are remaining nodes among the plurality of nodes that are not included in the selected possible ring. The method may further include selecting another possible ring if it is determined there are remaining nodes.

Abstract: Having a fast method to perform impairment evaluation is useful for many networks. A method or corresponding apparatus according to an example embodiment of the present invention maintains a traffic engineering database of values representing characteristics of links in the network through storage of integer values representing advertised optical signal capabilities of links between the multiple optical nodes. The example embodiment determines a path through the network for optical wavelengths to be supported by the links represented in the database as a function of evaluating optical signal characteristics at each link along a possible path using the advertised optical signal capabilities and provides a selected path meeting an acceptable integrity of the optical wavelengths to a path establishment module to establish the path through the optical network. Example embodiments significantly reduce computational complexity associated with impairment evaluation and path selection in an optical network.

Abstract: CXP is a telecommunications connector standard based on cage assemblies originally designed for copper cables. Optical transceivers dissipate more heat than copper cables, however, so cage assemblies designed for copper cables cannot remove heat adequately for proper transceiver operation. One embodiment of the inventive cage assemblies removes heat from an optical transceiver with a heat spreader, which protrudes through an aperture in a cage, and a compressible gap pad in thermal contact with the heat spreader. Inserting the optical transceiver into the cage places the transceiver in thermal contact with a heat spreader and pushes the heat spreader out of the cage, which, in turn, causes the gap pad to come into thermal contact with a heat pipe and/or a heat sink. The embodiment provide a low mechanical profile to support high-density circuit board configurations for high-density optical connectivity systems, such as used in Dense Wavelength Division optical networking.

Abstract: In today's reconfigurable optical add/drop multiplexer (ROADM) based optical node, ROADMs multiplex (and demultiplex) colored optical signals to form wavelength-division multiplexed (WDM) signals. Transponders connected to the ROADMs' add/drop ports convert noncolored optical signals to colored optical signals (and vice versa). Dedicating transponders to given ports degrades the node's ability to route around network failures. Example embodiments of the invention include an optical node and corresponding method for routing optical signals within an optical node that compensate for this inflexibility. The optical node may include two ROADMs to transmit respective WDM signals onto at least two internode network paths and a routing module that can direct channels of the same wavelength along different internode network paths.

Abstract: Due to demand for more network bandwidth, a need for multi-user optical network topologies has, and will continue to, increase. A method or corresponding apparatus in embodiments of the present invention provide for an availability determination tool for determining and displaying wavelength and subrate availabilities within a network. Benefits of embodiments of a tool include allowing a user to identify the availability and capacity of any wavelength on any network, via an interactive graphical user interface, such as by using three-dimensional representations. In one embodiment, the disclosed availability determination tool allows users to locate and view any combination of available wavelengths between nodes in an optical network topology, and generate graphical and tabular reports of the availability in order to maintain an efficient and organized method or apparatus for determining and controlling wavelengths in a network.