Abstract: A system and method for topology constrained routing policy provisioning between a plurality of sites in a Virtual Private Network (VPN) is disclosed. The method comprises enabling graphically defining of relationships between the plurality of sites of the VPN; and automatically generating at least one routing rule for each site of the VPN based at least in part on the defined relationship.

Abstract: A system and method for topology constrained Quality of Service (QoS) provisioning between a plurality of sites in a Virtual Private Network (VPN) is disclosed. The method comprises enabling graphical definition of relationships between the plurality of sites of the VPN and enabling graphical definition of at least one QoS rule for at least one pair of sites of the plurality of sites of the VPN based at least in part on the defined relationship.

Abstract: A system of route target filtering includes an import filter receiving a plurality of routes having a next hop routing information. The import filter accepts a first subset of the routes according to an import target policy. The system further includes a re-export filter also receiving the plurality of routes. The re-export filter modifies the next hop information of a second subset of the routes, and distributes the modified routes.

Abstract: Metal spring gaskets for EMI shielding in linecard plug-in units are improved by coverings of conductive fabric adhered to the springs with conductive adhesive.

Abstract: Each switch along a call setup path in a network decides whether the call request should be upgraded from a non-flow-controlled service type to a flow-controlled service type. Each switch bases the decision on whether a boolean variable for the calling subscriber that appears in a management information base (MIB) is set to a value indicating that the subscriber is entitled to the upgrade. In addition, the upgrade is performed only if an interface on the route to the called party on which the call setup request is to be forwarded supports flow-controlled connections. When the call is to be upgraded, the switch replaces the service type indicator in the setup message with a value indicating a flow-controlled service type, and forwards the setup message toward the called subscriber.

Abstract: An optical system includes a number of substantially identical, tunable, wavelength-preserving, optical regenerators 10. Each of the regenerators 10 is tuned to a different wavelength so that when a regenerator 10 is tuned to a given wavelength that regenerator will generate a regenerated, reshaped and retimed optical signal at the same given wavelength. The system also includes a multiplexer 32 coupled to receive and combine regenerated optical signal from each of regenerators. A filtering system (34) is provided, either internal or external to regenerators 10, to demultiplex different wavelength signals from an aggregate WDM optical signal.

Abstract: In a usage parameter control device for an asynchronous transfer mode communications system, a determination is made as to whether either of the respective storage elements maintaining values for (1) the time of arrival of a cell (TTA) and (2) the time value at which the “bucket” will have drained to an empty condition (TTAT) has wrapped relative to the other. The wrap determination is made prior to the comparison between the TTA and TTAT values which is made in order to determine whether the user is complying with his or her contracted parameters. If one of the storage elements has wrapped relative to the other, the comparison between the TTA and TTAT values is modified accordingly.

Abstract: A method for allocating transmission bandwidth to a group of real-time variable bit rate connections includes determining an acceptable cell loss probability for a real-time variable bit rate group based on quality of service requirements for real-time variable bit rate connections in the real-time variable bit rate group. An allocation bandwidth is determined for the real-time variable bit rate group from a probability density function of an aggregate cell arrival rate for the real-time variable bit rate group. The allocation bandwidth is the bandwidth that the probability of the aggregate cell arrival rate exceeding the bandwidth is less than or at least substantially equal to the acceptable cell loss probability.

Abstract: In a usage parameter control device for an asynchronous transfer mode communications system, a time counter is divided into multiple phases to enable audits of each of the virtual connections being handled by the system to be performed on a staggered group-by-group basis rather than all at once, thereby avoiding excessive delays in cell processing.

Abstract: A network device operates to control the clumping of cells on a connection using a rate-based flow-control protocol. In each of successive intervals, a number N is calculated representing the maximum number of cells permitted to be transmitted consecutively. N is calculated as the quotient from dividing a cell delay variation tolerance (CDVT) by the difference between the reciprocal of an allowed cell rate (ACR) and the reciprocal of a link cell rate (LCR). If the calculated quotient is greater than a number NRM for the connection indicating the maximum number of data cells allowed between forward flow-control cells, then N is set equal to NRM. A value C is calculated as the largest integer factor of NRM that is no greater than N, and the interval is then divided into NRM/C sub-intervals. No more than C cells are allowed to be transmitted on the connection in each of the sub-intervals.

Abstract: A lightpipe system for transferring light from light sources on a printed circuit board (PCB), such as light-emitting diodes (LEDs), to a display includes modular lightpipes coupled together. Each modular lightpipe couples to an adjacent modular lightpipe to form an integrated lightpipe system. All or selected numbers of the lightpipes may include detachable tabs, proturbances, pegs, or other structures to ensure proper alignment of the lightpipe system and attachment of the lightpipe system to the PCB.

Abstract: LAN interface logic (33) receives frames from a LAN segment (32), and frame transport logic (40, 54, 56) transfers frames to and from an ATM network. Forwarding logic (36) is used to (i) determine whether a mapping between a destination address (DA) and a virtual connection (VC) in the ATM network exists, (ii) forward frames containing a known DA to the frame transport logic for transfer to the ATM network, (iii) forward frames containing unknown DAs to the frame transport logic for transfer to a broadcast and unknown server (BUS 74) in the ATM network, and (iv) pass unknown DAs to a LAN emulation client (LEC) processor (42, FIG. 5) to resolve the address. The LEC processor creates a LAN emulation address resolution protocol (LE_ARP) request message containing the unknown DA, and the LE_ARP request message is transferred to a LAN emulation server (LES 76). The LES returns an ATM address of a remote LEC via which the destination node can be reached.

Abstract: A test station is provided to test a circuit board unit. The test station includes a disk drive storing uncompiled files which are interpretatively processed in order to carry out test operations. A bar code reader can scan a label on the unit, in order to accurately identify the unit. The label information can be used to ensure accurate programming of any programmable devices on the unit, and accurate selection of the correct test definition files for the unit. Step-by-step instructions can be provided to an operator regarding every manual act required during a test definition, and can include a graphic image of each such manual act. The test station can have two different test modes, where at least one command of the test definition is carried out for one mode but not the other. The test station has a debug mode, which includes capabilities for breakpoints, step mode, dynamic alteration of test definitions, and dynamic observation and alteration of variables.

Abstract: Network interface logic includes first logic executing a credit-based flow-control protocol (e.g., Quantum Flow Control or QFC) and second logic executing a rate-based flow control protocol (e.g. Explicit Rate or ER). The second logic transfers data cells between a network link and the first logic and inserts and extracts forward (FRM) and backward (BRM) flow-control/resource management (RM) cells. The second logic further (i) obtains cell buffer utilization information from the first logic, (ii) supplies transmission credits to the first logic based on rate information in BRM cells, (iii) induces the first logic to emit “dummy” RM cells when an RM cell is to be transmitted, and (iv) converts the dummy cells to either FRM or DRM cells for forwarding on the link. Rate information in the transmitted RM cells is calculated from the buffer utilization information and rate information in extracted BRM cells.

Abstract: The invention provides a method and system for managing electrical power flow among a plurality of loads or devices, which can be classified into critical loads (as to which maintaining power flow for a maximal period is a priority) and non-critical loads (as to which power flow may be cutoff when available power becomes limited). The invention is of particular use for rationing backup battery power among a plurality of data communications or telecommunications devices or services, whereby one or more less-crucial, and perhaps power-intensive, devices may be provided with a guaranteed duration of backup battery power (to perform an orderly shutdown, for instance), while a more-crucial, and perhaps less power-intensive, device is supplied with a longer duration of backup battery power, such that as the unavailability of primary power continues, crucial functions are maintained.

Abstract: An equipment enclosure includes a set of features enabling alignment of an electronic component with an L-shaped wall bracket. The bottom of the component rests on a base of the bracket. A rear wall of the bracket includes fastener elements, such as threaded standoffs, and alignment posts that extend forward beyond the standoffs. The rear of the component likewise includes fastener elements, such as captive screws, and alignment openings. During installation, the component is brought into a position in which the alignment openings engage the alignment posts, and then the component is pushed rearward until it abuts the rear wall of the bracket. The fasteners become mutually aligned for subsequent fastening.

Abstract: A method for allocating transmission resources to a constant rate connection includes determining a maximum cell clumping value for a constant rate connection based on a peak cell rate and a cell delay variation tolerance for the constant rate connection. An allocation bandwidth is determined for the constant rate connection based on the maximum cell clumping value. The allocation bandwidth comprises the bandwidth at which no cells of the constant rate connection are lost and the cell delay variation tolerance for the constant rate connection is satisfied. The allocation bandwidth is allocated at a network element for transmission of the constant rate connection.

Abstract: A fiber cable storage and management apparatus. The apparatus includes front and rear sections interconnected by a hinge. The front section is configured to hold a length of fiber cable, and both the front and rear sections are slidingly mountable to an electronic chassis. The front section of the fiber cable storage and management apparatus may be alternately retracted out of and inserted into the housing of the electronic chassis. When the front section is retracted out of the electronic chassis housing, the hinge can pivot between a first position in which the front and rear sections of the apparatus are substantially coplanar and a second position in which the front section is rotated below the plane of the rear section. By sliding the front section of the apparatus out of the electronic chassis housing and then rotating the front section downward, easy access is provided to fiber cable stored on the front section.

Abstract: A network access device includes a cell buffer memory (54) and segmentation and reassembly (SAR) logic (40) between multiple local area network (LAN) interface logic blocks (33, 36) and logic (56) interfacing with a cell-based network such as ATM. The cell buffer memory can be programmably partitioned into distinct buffer regions, each being associated with a respective LAN and with a respective set of virtual connections on the cell-based network. The SAR logic segments received frames into groups of cells, stores each group of cells into the buffer region associated with the respective LAN, and transfers the groups of cells from each buffer region to the cell-based-network interface logic via the associated virtual connections. The SAR logic and the cell memory are shared among multiple LAN bridges implemented by the LAN interface logic blocks and the cell-based-network interface logic, while traffic from the different bridges is kept separate.

Abstract: A system and a method are disclosed for supporting multiple application traffic types over connection oriented networks. Data is received from multiple applications, for example in the form of data units, and is associated with a traffic type. The traffic type associated with a data unit indicates whether the data unit is inelastic traffic or elastic traffic. Data associated with inelastic traffic is mapped to at least one connection of a first connection type which provides for some amount of committed bandwidth, and limits on delay variation. Data associated with elastic traffic is mapped to at least one connection of a second connection type, which does not provide any committed bandwidth. Connections of the second connection type may ensure that elastic traffic data units that are accepted for transfer by the underlying network are delivered without loss due to network congestion, for example, by use of a flow control technique.