Abstract: Methods, apparatus and articles of manufacture (e.g., physical storage media) to perform centralized route determination in communication networks (e.g., such as software defined networks) are disclosed. Example methods for route determination disclosed herein include accessing, with a controller of a software defined network, a first set of constraints specifying whether route splitting is permissible for respective ones of a set of flows in the software defined network. Such disclosed example methods also include accessing, with the controller, a second set of constraints specifying respective bandwidth demands for the respective ones of the set of flows in the software defined network. Such disclosed example methods further include determining, with a linear programming model implemented by the controller, a set of routes based on the first and second sets of constraints, wherein the set of routes is to route the set of flows in the software defined network.

Abstract: Methods, apparatus and articles of manufacture (e.g., physical storage media) to perform centralized route determination in communication networks (e.g., such as software defined networks) are disclosed. Example methods for route determination disclosed herein include accessing, with a controller of a software defined network, a first set of constraints specifying whether route splitting is permissible for respective ones of a set of flows in the software defined network. Such disclosed example methods also include accessing, with the controller, a second set of constraints specifying respective bandwidth demands for the respective ones of the set of flows in the software defined network. Such disclosed example methods further include determining, with a linear programming model implemented by the controller, a set of routes based on the first and second sets of constraints, wherein the set of routes is to route the set of flows in the software defined network.

Abstract: In a tool for use by network planners in designing metropolitan IP aggregation networks, several optimization methods are integrated into a tool. A k-means algorithm is used to choose access packet switch locations. A dual-k-means algorithm is used to choose the backbone switch locations. Each access packet switch is dual homed to two backbone packet switches using two diverse paths. The diverse path configuration is found using a maxflow-mincost algorithm on a modified fiber map topology. The link topology connecting the backbone packet switches to each other is designed using a heuristic that creates a skeleton network topology and then adds express links one by one, testing each link to assure reduced overall network cost. The resulting network topology is then improved upon by local search.

Abstract: A communication system includes a plurality of devices, such as cable modems, in communication with a station, such as a cable modem termination system, that provides efficient upstream bandwidth sharing.

Abstract: A communication system includes a plurality of devices, such as cable modems, in communication with a station, such as a cable modem termination system, that provides efficient upstream bandwidth sharing.

Abstract: A model is provided for optimizing an optical network wherein single links carry multiple signals by using multiple color channels. The routes in the optimized network minimize mid-route color changeovers, reducing the number of nodes requiring optical-electric-optical signal conversion. In the model, the minimized objective function includes terms representing total color miles, terms penalizing changeovers, and terms representing total nodes passed by routes.

Abstract: A model is provided for optimizing an optical network wherein single links carry multiple signals by using multiple color channels. The routes in the optimized network minimize mid-route color changeovers, reducing the number of nodes requiring optical-electric-optical signal conversion. In the model, the minimized objective function includes terms representing total color miles, terms penalizing changeovers, and terms representing total nodes passed by routes.

Abstract: A methodology for optimizing the cost associated with access charges incurred by network service providers when leasing communications facilities from a local service provider has been developed that incorporates physical reconfiguration of the access network topology as a cost-saving measure, where and when appropriate. The methodology identifies opportunities to reduce access charges by performing the following functions: (1) moving T1 facilities from one hub location to another; (2) moving T1 facilities from one T3 facility to another (at the same hub location) in order to disconnect unneeded T3 facilities; and (3) adding new T3 facilities in order to reduce overall access expenses and/or to provide new capacity for future growth, including adding potential new hub locations. The methodology is appropriate for use with various types of network facilities, T1 and T3 being considered as exemplary only.

Abstract: This description provides tools and techniques for detecting failures in IP networks using long packets. These tools may provide apparatus for monitoring several different communication paths between route processor modules within a given communications network. The apparatus selects one of the communication paths for connectivity testing, and sends both short and long test packets over the selected communications path. The apparatus then evaluates whether the test packets are transmitted successfully along the communication path.

Abstract: A methodology for optimizing the cost associated with access charges incurred by network service providers when leasing communications facilities from a local service provider has been developed that incorporates physical reconfiguration of the access network topology as a cost-saving measure, where and when appropriate. The methodology identifies opportunities to reduce access charges by performing the following functions: (1) moving T1 facilities from one hub location to another; (2) moving T1 facilities from one T3 facility to another (at the same hub location) in order to disconnect unneeded T3 facilities; and (3) adding new T3 facilities in order to reduce overall access expenses and/or to provide new capacity for future growth, including adding potential new hub locations. The methodology is appropriate for use with various types of network facilities, T1 and T3 being considered as exemplary only.

Abstract: A methodology for optimizing the access charges paid by a long distance carrier involves the use of a “sizing” operation to determine the optimal balance between direct trunks and access tandems (on a per LATA basis) so as to provide minimal access charges. Once the sizing has been completed, a mixed integer program is used to find the optimal MUX assignments for each LATA. The sizing operation is then re-visited, based on the MUX assignments, to determine if adjustments are required to reduce costs. Any changes in the sizing are then reviewed in the MUX assignment mixed integer program. The end result is a definition of the quantity of direct trunks, access tandem trunks and overflow minutes-of-use charges for each end office, as well as the number of high capacity facilities required for each MUX.

Abstract: A method and apparatus for assigning nodes to CMTS cards in a communication system. In order to avoid bottlenecks and to efficiently use resources of the cards in a hybrid fiber-coax architecture, the nodes are assigned to the cards using linear programming techniques so as to distribute the traffic load and minimize the unused capacity of each card. The number of households, nodes and cards are determined and used to establish a model which is then implemented using linear programming techniques to determine an optimal solution.

Abstract: A method and apparatus for assigning nodes to CMTS cards in a communication system. In order to avoid bottlenecks and to efficiently use resources of the cards in a hybrid fiber-coax architecture, the nodes are assigned to the cards using linear programming techniques so as to distribute the traffic load and minimize the unused capacity of each card. The number of households, nodes and cards are determined and used to establish a model which is then implemented using linear programming techniques to determine an optimal solution.

Abstract: A method and apparatus for assigning nodes to CMTS cards in a communication system. In order to avoid bottlenecks and to efficiently use resources of the cards in a hybrid fiber-coax architecture, the nodes are assigned to the cards using linear programming techniques so as to distribute the traffic load and minimize the unused capacity of each card. The number of households, nodes and cards are determined and used to establish a model which is then implemented using linear programming techniques to determine an optimal solution.

Abstract: A method and system for securing data stored in a secured partition of a storage device coupled to a computer having an insecure operating system that is subservient to a secure operating system operating on the computer. When access to the secured partition is detected, the secure operating system is interrupted and the insecure operating system is preempted, thereby preventing the insecure operating system and tasks being subservient thereto from accessing the secured partition.

Abstract: A communication system includes a plurality of devices, such as cable modems, in communication with a station, such as a cable modem termination system, that provides efficient upstream bandwidth sharing.

Abstract: An embodiment of the system and method of the present invention organizes the recovery of a communications network to minimize the interference between the recovering nodes and thus allows for a faster recovery. A metered rate is calculated at which nodes recover from a major network failure; when nodes recover at the metered rate, the network recovers quickly but without performance degrading interference. A measure of the interference between recovering nodes may be created; the interference measure may be used to partition the network, where the nodes within each partition set interfere minimally with each other during recovery and each set recovers separately. Recovering items (nodes or sets) may be sequenced so that each item recovers substantially separately in time, but where adjacent sequence items recover with some temporal overlap.

Abstract: An apparatus and method for routing calls to communication processing centers based on an optimal destination plan. Calls are allocated on the basis of area codes, regions, or other predetermined categories to particular communication processing centers. Each communication processing center's free capacity is calculated for all time intervals and this result is used to ascertain the smallest free capacity of any time interval for each communication processing center. The calls are then reallocated through linear programming methods such that the amount of smallest free capacity is maximized in order to determine the optimal call allocation scheme.

Abstract: An arrangement is disclosed for allocating a constrained common resource among a plurality of demands for the resource. The arrangement includes generating a set of patterns as candidates for a recommended solution, setting goals or constraints for a pattern to meet before the pattern becomes a candidate for the recommended solution, searching the set of patterns and determining those patterns that meet the goals, and appending those patterns that meet the goals to the recommended solution. A random distribution based on the demand for the resource over a multi-dimension space can be generated. Responsive to the random distribution, a plurality of feasible patterns can be generated. Responsive to the feasible patterns, a multiplicity ratio may be generated. Responsive to a multiplicity ratio and to its corresponding feasible pattern, the plurality of feasible patterns may be reduced to a single feasible pattern, which can be included in the recommended solution.