Abstract: There is provided a line redundant method for implementation of line switching in a switching matrix, including the bridge step of outputting a data signal to a plurality of redundant lines in the switching matrix, and the selector step of selecting only a data signal, of a plurality of data signals input from another switching matrix other than the switching matrix through the plurality of redundant lines, which is input through a redundant line required in the switching matrix, and not selecting the data signals input to the switching matrix through the lines other than the required redundant line. A line redundant system for implementing this method is also provided.

Abstract: To provide a switching system with telephone switching function mainly on the basis of hardware processing by using isochronous channel which is a real time communication channel. The switching system comprises a gateway node connected with ISDN (Integrated Services Digital Network) and PSTN (Public Switched Telephone Network), and one or more extension nodes, and a serial bus such as IEEE 1394 bus. The gateway node transforms data rate of outside line into data rate of extension node, and the other way around, and secure a seamless communication channel. Concretely, the gateway node secures an isochronous channel, according to a request from the extension nodes or the outside line, and executes switching such as transfer or reservation. A resource manager holds a table for managing the gateway node and extension node.

Abstract: A packet processing method for exchanging packet data through a plurality of layers is disclosed, that comprises the steps of storing the entire packet to a packet memory; and storing part of each packet of the packet data used in processes of a layer 2 processing portion and a layer 3 processing portion of the plurality of layers to a multi-port shared memory, the layer 2 processing portion and the layer 3 processing portion accessing the same memory space of the multi-port shared memory. In addition, a pipeline processing system is used so that when the layer 2 processing portion and the layer 3 processing portion access the shared memory, they do not interfere with each other.

Abstract: A high speed transmission system transfers data streams over a set of data links. Each data link may carry a number of bit streams. A clock signal is not transmitted over the optical link. Instead, an indication of the appropriate clock signal frequency and please is embedded in the transmitted data. At the receiving end, a clock signal of an appropriate frequency and phase is generated. The new clock signal is used to sample and reconstruct the original data streams.

Abstract: Principles of the invention are directed to techniques for allowing a router forwarding packets within a computer network to perform two or more forwarding tree decisions per memory access. The router may implement forwarding information in the form of a radix tree having a number of nodes, and received packets may contain keys identifying a packet destination. The router may traverse the tree by testing two or more path control bits within the key per each of the traversed nodes. The values of the path control bits in the key determine the path traversed along the tree. The router also stores intermediate bit patterns at each node and tests intermediate bits in the key to determine whether a particular node is the best match to the routing prefix contained in the key, thereby eliminating a need to backtrack up the tree.

Abstract: A cable modem termination system may include a number of receivers and a number of input ports configured to receive bursts of data from a number of cable modems on a number of channels. At least one receiver of the number of receivers may be configured to receive and decode bursts of data on at least one channel according to a first control signal. An input selector may be connected between the number of input ports and the number of receivers. The input selector may be configured to route bursts of data from the number of input ports to the number of receivers according to a second control signal.

Abstract: A system receives data in multiple streams from an upstream device. The system temporarily stores the data in a first buffer and asserts a forward flow control signal when a capacity of the first buffer exceeds a first threshold value. The system reads the data from the first buffer and selectively processes the data based on the forward flow control signal. The system temporarily stores the selectively processed data in a number of second buffers, generates a backward flow control signal when a capacity of one of the second buffers exceeds a second threshold value, and sends the backward flow control signal to the upstream device.

Abstract: A device comprises a programmable communication interface and a processor. The programmable communication interface communicates data via a set of signals. The processor configures the programmable communication interface to communicate the data in accordance with a programmed override state for at least one of the signals and actual states for the remaining signals. The programmable communication interface may be configured, for example, to programmably treat an overridden signal as asserted or de-asserted regardless of actual voltages present on one or more electrical connectors associated with the overridden signal. As a result, incorrectly wired electrical connectors of the programmable communication interface may be programmably overridden. Consequently, a technician need not manually rewire the programmable communication interface.

Abstract: In general, this disclosure describes techniques of selecting routes for network packets through a computer network based, at least in part, on electrical power procurement arrangements of devices in the computer network. As described herein, there may be a plurality of routes through a computer network from a first device to a second device. Each of these routes may include one or more devices that consume electrical power. A route selection device may make a determination regarding how network packets are to be routed among these routes based, at least in part, on arrangements made to procure the electrical power consumed by the devices along the routes. After the route selection device makes this determination, the route selection device may cause network packets to be routed among these routes in accordance with this determination.

Abstract: Requests from a client to a network device are authenticated based on a session ID obtained by the network device. Requests may be authenticated by obtaining a session ID value when a session is initiated and transmitting a document to the client that embeds the session ID in such a manner that additional requests to the network device based on the document include the session ID in the request. The additional requests are authenticated based on a determination of whether the session ID is included in the additional requests.

Abstract: A pipeline scheduler provides a minimum bandwidth guarantee by transporting cells from an input port to an output port in a two-phased approach. Cells that conform to a minimum cell rate (MCR) are selected from queues at the input port and arranged into supercells for transport to the output port, followed by nonconforming cells, to guarantee fairness by using scheduling modules to build the supercells first for conforming cells, and then for nonconforming cells. Reservation vectors are used to permit the same time slot of the next frame to be reserved by a first queue, and the same time slot of the following time frame to be held for reservation by a second queue, to ensure equal time slot access by the first and second queues over successive time frames.

Abstract: A network device may include logic configured to detect that an event has occurred in the network device, determine an XML document structure based on the detected event, and generate an XML document with the determined structure including information relating to the detected event.

Abstract: Scheduling virtual upstream channels within one physical upstream channel is disclosed. The MAP messages of the virtual upstream channels that share the same physical upstream channel are synchronized together such that any one transmission opportunity for a given virtual upstream channel does not overlap with transmission opportunities of any other virtual channel. This includes converting all requests for tranmission opprotunities into a common unit and then scheduling these requests as appropriate.

Abstract: A network device may include logic configured to invoke proactive programs based on the expiration of a long time period within the network device, wherein the proactive programs collect data relating to operations of the network device, invoke reactive programs based on the detection of at least one of an event or expiration of a short time period, wherein the reactive programs collect, correlate and analyze data relating to the detected event or expiration of a short time period, determine a corrective action based on collected and analyzed data, and perform the determined corrective action within the network device.

Abstract: A network router includes a set of interface cards to receive packets from a network, and a set of accounting modules to calculate flow statistics for the packets. The router further includes a control unit to adaptively update routing information in response to the calculated flow statistics, and to route the packets in accordance with the routing information. The control unit identifies potentially malicious packet flows for the received packets based on the flow statistics, and applies an intercept filter to intercept the packets of the identified packet flows. The control unit analyzes the intercepted packets in real-time to determine the presence of a network event, and updates the routing information based on the determination, e.g., by terminating routing for packets associated with malicious packet flows. In this manner, the router may adaptively respond to network events, such as network security violations.

Abstract: Reversible airflow in cooling systems of electronic devices is described. For example, an electronic device may include a reversible fan tray. The fan tray may include symmetric mounting features that allow the fan tray to be mounted in the electronic device in more than one orientation at the same location within the electronic device such that one or more fans in the fan tray either direct air into the electronic device or to pull air from electronic device. The fan tray may further include a symmetric arrangement of connectors that coincide with the symmetric arrangement of mounting features to allow the fan tray to be connected to a power source of the electronic device any of the more than one orientations. An arrangement of electronic devices including reversible fan trays may be configured so that inlet and outlet airflows are separated to increase cooling efficiency of the electronic devices.

Abstract: A router includes a detection module to detect a presence of the network attack, such as a denial of service (DOS) attack. The detection module may, for example, include counters indicating a number of packets processed for various network protocols supported by the router. The detection module enables a rate-limiting operating mode for the router when one or more of the counters exceed a protocol-specific threshold. Under normal traffic levels, the router receives inbound packets using interrupt-driven service routines. When a network attack is detected, however, the router dynamically switches modes and processes the patents using a finely controlled software process. This allows the software process to control the computing resources allocated to servicing packets during a network attack, thereby reserving sufficient resources for lower priority software processes to process the packets and service other tasks.

Abstract: Techniques are described that allow a network device, such as a router, to dynamically build VLAN interfaces based on subscriber information strings included within packets. In particular, the network device comprises an interface controller and a forwarding controller, where the forwarding controller receives the packet over an Ethernet port and forwards the received packet to the interface controller. The packet includes both Ethernet tagging information and a subscriber information string. The interface controller comprises an Ethernet module that dynamically builds a primary virtual local area network (VLAN) sub-interface (PVS) based on the Ethernet tagging information. The Ethernet module also dynamically builds a subscriber VLAN sub-interface (SVS) based on the subscriber information string. The SVS allows the network device to distinguish between subscribers residing on the same VLAN, and, therefore, to provide subscriber specific services.

Abstract: A method and an apparatus for rapidly resuming, at times of failures, network traffic in a connection-oriented network by using an alternative route pre-computed and stored locally in nodes along an initial route without requiring signaling of upstream nodes or a master server.

Abstract: A method and apparatus for switching a data packet between a source and destination in a network. The data packet includes a header portion and a data portion. The header portion includes routing information for the data packet. The method includes defining a data path in the router comprising a path through the router along which the data portion of the data packet travels and defining a control path comprising a path through the router along which routing information from the header portion travels. The method includes separating the data path and control path in the router such that the routing information can be separated from the data portion allowing for the separate processing of each in the router. The data portion can be stored in a global memory while routing decisions are made on the routing information in the control path.