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: 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: 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: 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 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.

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: An asynchronous transfer mode (ATM) based service consolidation switch (10) includes an input/output module (22) having a to-switch port (TSPP) processor (90) and a from-switch port processor (FSPP) (92). The TSPP (90) and the FSPP (92) communicate with a bandwidth arbiter (114), multipoint topology controllers (116), and a data crossbar (117) on a switch control module (32). The TSPP (90) receives traffic over links for conversion into an internal cell format. Internal cells are buffered until allowed to transfer to an appropriate FSPP (92). Multipoint topology controllers (116) performs translations for internal switch flow control through interactions between the TSPPs (90), FSPPs (92), and the bandwidth arbiter (114). The bandwidth arbiter (114) performs appropriate bandwidth arbitration to allow internal cells to flow from TSPPs (90) to FSPPs (92) over the data crossbar (117).

Abstract: An encoder/decoder is disclosed which is operative to convert an 8 bit value to a ten bit serial run length limited code for transmission over a serial data link. The encoding technique maintains DC balance within 2 bits over a single ten bit word and compensates for DC imbalance by inverting selected words in the transmission sequence to correct for a DC imbalance resulting from the transmission of a prior unbalanced word. One or more encoding lookup tables are employed at the encoder to map each byte into a ten bit run length limited code for serialization and transmission over the serial data link. A second decoding lookup table is employed at the decoder to map the received 10 bit run length limited code into the original 8 bit value.

Abstract: An apparatus and method for switching redundancy control which provides fast switching from a malfunctioning component to a redundant component with minimum data flow interruption for both transmitted and received data. The redundancy control system having an APS (Automatic Switching Protection) Hub, at least a working and a redundant tributary card, a bridge to provide identical traffic to the working and redundant tributary cards, a working and a redundant STM switching fabric, selectors within the working and redundant STM switching fabrics for selecting the traffic from the working tributary card to further process, a working and a redundant ATM switching fabric, a working and a redundant ATM processor and ATM selectors for selecting traffic needing cell switching from the working STM switching fabric to process further.

Abstract: An advanced SONET add/drop multiplexer capable of supporting packet over SONET and multiprotocol label switching. The add/drop multiplexer is capable of adding and/or dropping both STM and packet traffic, such as Internet Protocol traffic. This SONET add/drop multiplexer allows Internet Protocol streams which are added or dropped at different nodes to be carried over the same SONET path in a network, thereby greatly saving bandwidth.

Abstract: A multiple time domain serial-to-parallel converter includes a combiner operable to receive a stream of serial data within a first time domain and to accumulate a portion of the serial data into a set of parallel data. A first hold register is coupled to the combiner. The first hold register is configured to operate within the first time domain and operable to load the set of parallel data in response to a first load signal based on the first time domain. A second hold register is coupled to the first hold register. The second hold register is configured to operate within a second time domain and operable to load the set of parallel data from the first hold register in response to a second load signal based on the second time domain.

Abstract: An enclosure that includes at least first and second pieces of equipment having separate cooling airflows. A baffle is disposed within the enclosure to separate the enclosure into two compartments and to isolate the airflows for each piece of equipment within each of the respective compartments. The baffle includes a step portion to provide for a smooth airflow and to prevent hot spots from being formed on the baffle. The heated airflow from the second compartment is redirected away from the first compartment to an air duct or chimney that transports the heated air from the second compartment to an air output vent. When acting as a chimney, the air duct includes a flue portion, a buffer portion to enhance the convection draft, and an output opening. The separate airflows may be either convection driven or be a forced airflow driven by one or more fans.

Abstract: A communications device and method for effectively managing bandwidth within a telecommunications network carrying both time division multiplexed signals as well as data signals. The communications device having dialable TDM/cell and/or packet-based bandwidth management capability so that a network operator can select to manage bandwidth for any particular signal on in STS, VT, or cell or packet basis.

Abstract: Using a graphical user interface, the user is requested to enter a type of permanent virtual connection desired to be created. Based on the type of permanent virtual connection desired to be created, it is determined what data is necessary to generate the permanent virtual connection. Using a graphical user interface, the user is requested to enter the data determined to be necessary. When the user is requested to enter a type of permanent virtual connection desired to be created, information is requested from the user as to whether a point-to-point connection or a point-to-multipoint connection is desired, as to whether a virtual path connection or a virtual channel connection is desired, as to a desired quality of service, as to how billing data is to be collected, and as to a type of traffic to be handled by the permanent virtual connection. The data is assembled in a form recognizable by a telecommunications switch.

Abstract: An apparatus and method for switching redundancy control which provides fast switching from a malfunctioning component to a redundant component with minimum data flow interruption for both transmitted and received data. The redundancy control system having an APS (Automatic Switching Protection) Hub, at least a working and a redundant tributary card, a bridge to provide identical traffic to the working and redundant tributary cards, a working and a redundant STM switching fabric, selectors within the working and redundant STM switching fabrics for selecting the traffic from the working tributary card to further process, a working and a redundant ATM switching fabric, a working and a redundant ATM processor and ATM selectors for selecting traffic needing cell switching from the working STM switching fabric to process further.

Abstract: A method for monitoring the operating temperature within a card shelf having a plurality of discrete electronic cards includes receiving a first temperature indicative of an operating temperature of an item on one of the electronic cards. A second temperature indicative of an ambient temperature in which the electronic card is operating is also received. Based on the first and second temperatures, a temperature controller determines whether the item is operating within specified limits.

Abstract: An architecture for a SONET network element, such as a hybrid STM/ATM add-drop multiplexer. The disclosed system includes an interconnection system for a network element, including a line unit slot, a switch fabric slot, and two or more service unit slots. The line unit slot is connected as a hub to the switch fabric slot and the service unit slots in a first star interconnection configuration. The switch fabric slot is connected as a hub to the line unit slot and the service unit slots in a second star interconnection configuration. The star interconnection configurations provide fault isolation between different units, and allow for replacement of failed units without interfering with the links of other units to the hub. In a preferred embodiment, the switch fabric slot and one of the service unit slots comprise the same slot, thus permitting flexible configuration of the device within a minimal space.