Abstract: The present invention provides a high switching capacity network device in one telco rack including both physical layer switch/router subsystems and an upper layer switch/router subsystem. Instead of providing a single physical layer switch/router subsystem, multiple physical layer switch/router subsystems are provided. Segmenting the physical layer switch/router into multiple, for example, four, subsystems better utilizes routing resources by allowing etches for the physical layer subsystems to be moved away from the center of the mid-plane/back-plane of the network device. Moving the physical layer subsystem etches away from the center of the mid-plane enables the network device to include an upper layer/switch router subsystem with etches toward the center of the mid-plane.

Abstract: The present invention provides a computer system having a control process and a device driver process that is in communication with the control process, and a local back-up process, independent of both the control process and the device driver process. The local back-up process facilitates recovery of the device driver process. In one aspect of the invention, the computer system is a network device that includes a control plane and a data plan. The control plane includes a control process, and the data plane includes a device driver process. A local back-up process, independent of both the control process and the device driver process, facilitates recovery of the device driver process if the device driver process is terminated.

Abstract: Computer systems and methods of data processing are disclosed in which hierarchical levels of fault/event management are provided that intelligently monitor hardware and software and proactively take action in accordance with a defined fault policy. A fault policy based on a defined hierarchy ensures that for each particular type of failure the most appropriate action is taken. In one embodiment, a master Software Resiliency Manager (SRM) serves as the top hierarchical level fault/event manager, with one or more slave SRMs serving as the next hierarchical level fault/event manager. The software applications resident on each board can also include sub-processes (e.g., local resiliency managers or LRMs) that serve as the lowest hierarchical level fault/event managers.

Abstract: Computer systems and methods of data processing are disclosed in which hierarchical descriptors define levels of fault/event management to intelligently monitor hardware and software and proactively take action in accordance with a defined fault policy. A fault policy based on a defined hierarchy ensures that for each particular type of failure the most appropriate action is taken. Hierarchical descriptors can be used to provide information specific to each failure or event. The hierarchical descriptors provide granularity with which to report faults, take action based on fault history and apply fault recovery policies. The descriptors can be stored in a master event log file or local event log files through which faults and events may be tracked and displayed to the user and allow for fault detection at a fine granular level and proactive response to events. In addition, the descriptors can be matched with descriptors in a fault policy to determine the recovery action to be taken.

Abstract: A distributed software redundancy design is disclosed to minimize network outages and other problems associated with component/process failures by spreading software backup (in the so-called “hot state”) across multiple elements. The distributed redundancy architecture of the present invention also permits the location of the hardware backup element to float, that is, if a primary element fails, the functions can be transferred over to the backup element. When the failed primary element is replaced, the replacement hardware can serve as the hardware backup. If one or more of the primary processes on a particular element experiences a software fault, the processor on the line card may terminate and restart the failing process or processes. Once the process or processes are restarted, a copy of the last known dynamic state (i.e.

Abstract: The present invention provides a method and apparatus for facilitating hot upgrades of software components within a telecommunications network device through the use of “signatures” generated by a signature generating program. After installation of a new software release within the network device, only those software components whose signatures do not match the signatures of corresponding and currently executing software components are upgraded. Signatures promote hot upgrades by identifying only those software components that need to be upgraded. Since signatures are automatically generated for each software component as part of putting together a new release a quick comparison of two signatures provides an accurate assurance that either the software component has changed or has not. Thus, signatures provide a quick, easy way to accurately determine the upgrade status of each software component.

Abstract: The present invention provides methods for operating a computer system that call for executing a plurality of modular processes, providing a data file for use by the plurality of the processes, and incorporating a view identification within each of the plurality of processes to define data accessible by each process within the data file. The processes can include, for example, two identical processes that are executed simultaneously to access the same data within the data file in accordance with the same incorporated view identification.

Abstract: The present invention provides a network device including redundant, synchronous central timing subsystems (CTSs) and local timing subsystems (LTSs) including control circuits for automatically selecting between reference signals from both central timing subsystems. Automatically selecting between reference timing signals allows each LTS to quickly switchover from a failing or failed reference timing signal to a good reference timing signal. Quick switchovers prevent data corruption errors that may result during slow switchovers where a failing or failed reference signal is used for a longer period of time prior to the switch over. In addition, since each LTS independently monitors its received reference timing signals, a problem on one reference timing signal is quickly detected by the LTS and the LTS switches over to the good reference timing signal regardless of whether any other LTSs detect a problem with their received reference timing signals.

Abstract: The present invention provides a network device including redundant, synchronous central timing subsystems (CTSs) each having a voltage controlled timing circuit for receiving a constant master voltage signal and variable slave voltage signal. Each CTS also includes a control logic circuit for selecting the constant master voltage signal for use by the voltage controlled timing circuit when the CTS is master and for selecting the variable slave voltage signal when the CTS is slave. Using a constant master voltage signal eliminates the need for a separate master oscillator in each CTS. Oscillators are typically expensive, consume significant space on the printed circuit board and have location restrictions on where they may be placed on the printed circuit board.

Abstract: The invention provides a method for fault isolation in a computer system, such as a network device. The method calls for providing a plurality of modular processes, and forming groups, based on hardware in the computer system, of one or more of the plurality of modular processes. A fault within a group is detected, and recovery from the detected fault is accomplished without affecting processes or hardware in other groups.

Abstract: The present invention provides a network device, such as a network switch or a router, having a high degree of modularity and reliability. The network device includes a data plane and a control plane. The data plane relays datagrams between a pair of receive and transmit network interface ports. The control plane runs management and control operations, such as routing and policing algorithms which provide the data plane with instructions on how to relay cell/packets/frames. Further, the control plane includes an internal control device that is primarily responsible for managing the internal resources of the network device, and a separate external control device that is primarily responsible for operations relating to the interfacing of the network device with an external environment.

Abstract: The present invention provides a computer system having a modular control process, and a modular device driver process that works in conjunction with the control process. The device driver process is capable of continuing operation even if the control process is terminated, for example, upon detection of a fault. In one aspect, the invention provides a network device that includes a control plane and a data plane. The control plane includes a modular control application for establishing and terminating network connections, and the data plane has an independent, modular device driver process for transmitting data over network connections established by the control application. The device driver process is capable of continuing to transmit data over established network connections even if the control application is terminated.

Abstract: The present invention provides a method and apparatus for providing variable signal delays through stacked resistor pads. Stacked resistor pads include resistor pads mounted on both sides of a module where at least certain resistor pads on one side of the module are electrically connected to certain other resistor pads on the other side of the module through shared vias. Stacked resistor pads reduce the number of connections and vias required by conventional resistor pad combinations. Reducing connections and vias reduces the capacitance added to the delayed signal, which reduces potential signal degradation, especially at high-speeds. In addition, connections and vias lower the potential for manufacturing defects and errors due to missing or broken parts. Moreover, stacked resistor pads consumes significantly less module surface space than currently available resistor pad combinations.

Abstract: Connector test cards provide for improved printed circuit board (“board”) testability by terminating each etch routed to an unmated connector on the board. With the connector test card mated with the connector on the board under test, the integrity of solder joints between the connector and the board may be tested for opens and shorts on a standard in-circuit or fixtureless tester. In addition, during functional testing, a connector test card may be mated with a connector on the board to prevent the voltage levels on undriven component inputs on the board from floating.

Abstract: The present invention provides a method and apparatus for improving management and network availability by providing out-of-band management channels between network/element management system (NMS) clients and servers. High priority client requests and server notifications may be sent over the out-of-band management channels to ensure fast response times. In addition, periodic roll calls between NMS clients and NMS servers may be executed over the out-of-band management channels to allow for quick discovery of any disconnects and reclaiming associated client resources. Further, periodic roll calls may be conducted between the NMS servers and the network devices to which they are connected, and if a server discovers that a network device has gone down, it may send a high priority notification to appropriate NMS clients over the out-of-band management channels to ensure a fast response by the clients.

Abstract: The present invention provides a telecommunications network device including at least one power distribution unit capable of connecting to multiple, unregulated DC power feeds. The network device may also include a redundant power distribution unit. Both power distribution units are independently removable from the network device. Thus, when two power distribution units are mounted within the network device one may be removed for repair or upgrade and the other power distribution unit will continue to provide power to the network device such that it may continue running. Each power distribution unit may also include an on/off switch, which when in an “on” position allows the power distribution unit to supply power from each connected power feed to the network device and when in an “off” position prevents the power distribution unit from supplying power from any power feed to the network device.

Abstract: The present invention provides a method and apparatus for improving the configuration of virtual connections. Specifically, virtual path identifier (VPI) and virtual channel identifier (VCI) Availability Indexes are made available to network administrators. The Availability Indexes present valid, available values. Thus, the potential for misconfigurations is reduced and even less experienced network administrators may easily configure virtual connections. The Availability Indexes provide administrators with control over exactly which paths and channels are allocated for each connection while eliminating the guesswork and tracking burden present in current network/element management systems. Availability Indexes also reduce the time and frustration required to configure virtual connections.

Abstract: The present invention provides a method and apparatus for supporting multiple redundancy schemes in a single network device. In one network device, various redundancy schemes are supported including 1:1, 1+1, 1:N, no redundancy or a combination of redundancy schemes. In addition, the redundancy scheme or schemes for physical network device cards (i.e., universal port cards) or ports may be different from the redundancy scheme or schemes for forwarding network device cards. For example, a network manager may want to provide 1:1 or 1+1 redundancy for all universal port cards and/or ports but only 1:N redundancy for each N group of forwarding cards.