Abstract: A method of providing redundancy in a LAN Emulation network in the event an LES fails. The method is light in that it does not require complicated database synchronizations between LECSs and their associated complex message protocol exchanges. The method comprises defining a plurality of LESs per ELAN, but permitting only one of the LESs to be active at any one moment in time. All the LECSs are configured with the same Topology Database which include the all the potential LESs for each ELAN. The LECSs try to connect to each LES and the results are logged. The operative LESs having the highest priority is chosen as the active LES whereby all LECs get assigned to the active LES. When the active LES fails the LECs attempt a new connection to LECs. The LECs assigns the LECs to another operative LES in the database list. All the LECs previously connected to the failed LES, are attached to the new LES assigned by the LECs and communications are reestablished with the new LES.

Abstract: A radio frequency oscillator containing a means of frequency band selection and a tuning mechanism permitting frequency variation within each of the bands. The oscillator typically consists of a transistor, a frequency determining circuit, one or more voltage controlled variable capacitance diodes for frequency tuning and frequency range switching means to step change the operating frequency. The frequency determining circuit can consist of a lumped inductor, a microstrip line or a combination of a microstrip line and a lumped inductor. The frequency determining circuit is typically connected to the base of the transistor. In a preferred embodiment the frequency range switching is accomplished using an RF switching diode, used to short out one or more portions of the tuned microstrip line in accordance with the required frequency step change. The circuit also incorporates additional circuitry to support frequency modulation.

Abstract: A method of performing source routing when a node is in the overload state. A node in the overload state cannot perform routing functions in response to a SETUP message for destinations other than its directly connected neighbors. Instead, the node forwards the SETUP request to one of its directly connected neighbors. The neighboring node chosen must be able to support the overload routing feature, the link between the two nodes must be in the FULL state and the node chosen must not itself be in the overload state. The neighboring node chosen to calculate the source route receives a ROUTE REQUEST message encapsulating the information received from the source user. The neighboring node chosen then calculates the source route as if it was the node connected to the source user, i.e., the node in the overload state. The route, once calculated, is sent to the requesting node in the overload state.

Abstract: A method of permitting older networks based on E-IISP routing to operate in newer PNNI based networks. The invention combines the PNNI and E-IISP routing schemes and permits their simultaneous execution in the same ATM network. The E-IISP routing scheme is modified so as to operate in unison with the minimal PNNI implementation configured on each node. The Hello protocol and associated Finite State Machine (FSM) are utilized to determine whether a remote node is in the same peer group. If it is determined that both nodes are in the same peer group, the ports on either side of the link are configured as standard PNNI type ports. If it is determined that the two nodes are from different peer groups, the ports on either of the link are configured as E-IISP type ports. Foreign address information is then exchanged between the two nodes thus permitting border nodes to learn about other peer groups from their respective remote nodes.

Abstract: A method of determining an efficient route to a well known address that is particularly applicable to networks that do not have the capability of source routing for calculating routes to specific addresses such as ATM networks based on the IISP protocol. The well known address may represent any entity in the network that provides distributed services (e.g., network server applications) that are to be shared among many nodes and applications on the network, such as LECSs. The method of functions to automatically and dynamically register ‘well known’ addresses on the ports of each node that implements the invention. This permits applications on the network to route to the destination in the shortest possible path thus utilizing network resources in an efficient manner. If there is more than one location with the well known address, e.g., a redundant LECSs in the network, or more than one route to the location then the optimum location will be the one routed to.

Abstract: A multicast queue for controlling cell traffic to individual output queues in a multicast group in accordance with the backpressure information generated by each output queue. One or more destinations asserting the backpressure signal are identified and, in response, the corresponding one or more destinations are removed from the ‘distribution list’ in the routing tag associated with the connection. In this fashion, a cell that originated at a multicast source queue can be transmitted to the remaining destination queues that are not in a congested state. Cell traffic will cease only to those destination queues that generated the backpressure signal indicating that they are full. If the congestion at an output port is removed, the corresponding backpressure bit is reset and cell traffic resumes to that particular output port.

Abstract: A power switching and voltage regulation system utilizing a conventional switching element to provide distributed power switching and voltage regulation. The system utilizes a switching element to impose an impedance in a controlled manner to provide power to a load such as a plug-in module in an electronic apparatus. The power source supplying an input DC voltage is intentionally set to a higher voltage than the level required by the plug-in module. The voltage supplied is required to be sufficiently high such that the voltage delivered to the plug-in module, exceeds the maximum permitted voltage level of the voltage required by the particular plug-in module. Once the switching device is turned on, the switching element exerts an impedance which functions to drop the voltage supplied to the load to the required value. The impedance is generated in accordance with a feedback control signal.

Abstract: A caching method to greatly reduce the time to calculate routes based on the well known Dijkstra routing algorithm. A first embodiment is suitable for use in applications where only a single class of call is in use. A second embodiment is suitable for use where multiple classes of calls are is simultaneous use. A sequential number field and a global variable holding a sequential count are maintained by each node. When a node is put on the PATH list, the global sequential count variable is copied to the sequential number field for that particular node descriptor. Subsequently, when a route to destination node is to be calculated, for each node marked as a destination, the global sequential count variable and the node descriptor sequential number field are checked if they are equal. If they are, it means that a route has already been calculated to the destination which was already determined to be optimum.

Abstract: A method whereby local area network (LAN) multicast traffic flows are defined and set up by the network management system (NMS). Network efficiency is maximized and performance degradation of the network and workstations connected thereto is reduced. The method utilizes standard 802.1D bridging infrastructure built into conventional level 2 network switching devices to permit a administrator to define a multicast flow, otherwise known as a virtual LAN (VLAN) or a ‘Session VLAN,’ as a multicast application that can be mapped to a multicast MAC address. The multicast MAC address is then utilized in the transmission of the multicast messages. The NMS declares a session VLAN across all the level 2 devices in the network utilizing standard SNMP and members of the session VLAN can be added and removed. Each device then translates the SNMP requests to an operation on its standard 802.1D static addresses.

Abstract: A signaling cache suitable for use in networks, such as ATM networks, that utilize signaling in establishing calls. The invention functions to greatly reduce the amount of call processing required for calls that have been previously received and processed by the switch. The signaling cache can be implemented on each switch in the network to reduce the processing requirements network wide. Each switch along the call route functions to perform signaling processing only once for each unique call request. The results of the signaling processing are stored in a cache memory to enable re-use in the event a call request is receive that matches a previously received and processed call request. Signaling processing is performed for each request message having a particular set of characteristics, e.g., a set of IEs having a particular value. Anytime thereafter, when a signaling request having the same characteristics is received, the signaling process is bypassed and the results fetched from the cache memory.

Abstract: A method for performing topology database synchronization between two nodes wherein one of the nodes is in an overload state. The node in the overload state looks for a neighboring node directly connected to it that is not in the overload state. After such a node is found, the link to the neighboring node is intentionally dropped and subsequently re-established. This causes the neighboring node to transfer its entire knowledge of the network to the node in the overload state. The node in the overload state than functions to forward the topology database information to its other neighboring node. In this fashion, the portions of the network one either side of the link learn about the other side notwithstanding the fact that one of the nodes is in an overload state. Once the database synchronization process is complete, calls can then be initiated from either side of the network to the other side.

Abstract: A novel inductor termed a suspended printed inductor (SPI) and an LC-type printed filter constructed using the suspended printed inductor is disclosed. The LC-type suspended printed filter is formed over any suitable substrate material, such as a dielectric substrate, with greatly reduced effects on filter performance due to the characteristics of the material. SPIs are characterized by the absence of a ground plane. A ground plane may physically still exist but it is located at a sufficient distance form the printed circuit board such that the distance can be considered virtual infinity from an RF circuit perspective. A number of different types of inductors can be fashioned as a suspended printed type inductor, including serpentine line inductors or transmission line inductors. The suspended printed inductor can be utilized to construct numerous types of filters such as low pass, high pass, band pass, band stop or any combination thereof.

Abstract: A platform for holding a plurality of modules or printed circuit boards wherein the platform or chassis contains shutters placed over airflow openings in the platform. The shutters are normally closed and are opened by the act of inserting a module into the platform. The shutters are in the closed position in all slots not occupied by a module and are in the open state in all slots populated by a module. The shutters open as the module is inserted and close when the module is removed. The closed shutters prevent airflow from passing through the unpopulated slots and empty space within the platform, thus forcing the airflow to pass through the space in which the modules are present. The platform also comprises a means of controlling the number of fans that are operational in accordance with the number of modules installed in the platform. The fans closest to the modules inserted into the platform are operational while fans close to unpopulated slots are turned off.

Abstract: Two solutions are provided for optimizing the algorithm used by the local node in calculating the route to a destination node. A first method optimizes the route calculation by associating a port/link information with the PTSEs received by the node. The association is made using the first PTSE to arrive from an originating node. The routing algorithm is then steered to begin routing to a destination using the associated port/link. A second method optimizes the route calculation by utilizing a special PTSE termed a ROUTE.sub.-- PTSE into which is placed the route the PTSE takes upon being flooded from the creating node to the local node. When routing, the local node traverses the DTL already existing in the ROUTE.sub.-- PTSE received from a particular originating node that is the current destination node.

Abstract: An optical switch utilizing WDM or DWDM techniques for use in both WAN and LAN environments. Each input to the switch is assigned a separate wavelength via a tunable transmitter. The output of the transmitters are input to a star coupler which combines all the optical signals into a single optical output signal. This signal is input to an optical demultiplexor which functions to split the incoming optical signal into a plurality of separate wavelengths with each wavelength steered to a particular output port. The output of each port, corresponding to a particular wavelength, is then converted into an electrical signal by a receiver. Unicast, broadcast and multicast calls are supported. A plurality of unicast connections can be established simultaneously by assigning each tunable transmitter a different wavelength such that all wavelengths are mutually exclusive with each other.

Abstract: A timepiece having a novel display with an integral alphanumeric display is described. The display includes alternating light and dark bands to assist in the determination by a user of the current time. The display includes two columns of a dozen hourly indicators each for indicating the current hour. The left column represents AM hours and the right column represents PM hours. In a preferred embodiment, hour indicators on the left column can be set to indicate the hours from 12:00 midnight to 11:59 AM and hour indicators on the right column can be set to indicate the hours from 12:00 in the afternoon to 11:59 PM. In another preferred embodiment, the hour indicators on the left column represent the hours from 1:00 AM to 12:59 PM and the hour indicators on the right column represent the hours form 1:00 PM to 12:59 AM. Located around the perimeter of the display is a ring of sixty minute indicators.

Abstract: A novel strategy board game and method of play thereof is disclosed. The board game is played on a board having a playing surface arranged as a plurality of squares. The board is arranged as nine rows by five columns of squares. The squares alternate light and dark in checkerboard style. Two players each start a primary playing piece and four guards. The guards operate in pairs, with each player having two pair, and function to both protect a player's primary playing piece and attack the opponent's playing pieces. In the center square of the board sits the crown representing the princess. The object of the game is for a player to be the first to reach the princess with his/her primary playing piece. Players utilize their playing pieces to put squeezes on their opponent's playing pieces. A squeeze functions to force a player to move the squeezed piece. A squeezed playing piece can be rescued by their partner playing piece by raising the squeeze to a royal squeeze.