Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A method and system are provided for increasing processing efficiency associated with data frames transiting a network node having multiple ports. The method and system accomplish their objects via the following. A data frame having a header and data is received. An associated pointer for at least one portion of the received data frame is provided. The associated pointer is provided by segmenting each received data frame into parts, and associating with each segmented part a pointer. Thereafter, a portion of the received data frame is modified independent of other portions of the received data frame via utilization of given one or more of the associated pointers. Additionally, one or more copies of a portion (which can include the whole) of the received data frame is constructed by recalling each segmented part associated with one or more selected ones of the associated pointers. Furthermore, a determination is made as to whether the received header indicates unicast or multicast.

Abstract: A system for coupling a local area network to a wide area network utilizes a PCI (Peripheral Component Interface) bus to couple a PCI interface to a PCI network interface card, which is coupled to the wide area network. The wide area network could be an asynchronous transfer mode network or a high bandwidth ethernet. If the PCI network interface card operates as a PCI master, then the PCI interface will operate as a PCI slave. If the PCI network interface card operates as a PCI slave, then the PCI interface of the invention will operate as a PCI master.

Abstract: A method and system are provided for enabling simultaneous cut-through and store-and-forward transmission of frames in high speed network devices. A Buffer Parameter Vector chains multiple frame buffers together. Frame Parameter Vectors created for each unique version of a frame are used to manage frames as they flow through the network device. Cut-through/store-and-forward decision logic determines whether frames can be transmitted by cut-through or store-and-forward. Multiple unique frames or copies of a frame that are to be transmitted store-and-forward have their Frame Parameter Vectors chained together by pointers. The cut-through/store-and-forward decision logic steps through the chain of Frame Parameter Vectors resulting in the frames associated with each Frame Parameter Vector being transmitted.

Abstract: A device for interconnecting Local Area Networks (LANs) includes ports for attaching LAN segments and port modules for connecting the ports to a switch fabric. Each of the port modules include a mechanism which searches the Routing Information (RI) field of a Received frame to detect at least two Triplets (a minimum configuration for a LAN segment) indicating a Source path from an originator user and a Destination path to a destination user. The Triplet (single or in combination) is used to access a database (tables) which identifies the Port of Exit (POE) through which the frame is to be routed.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A method and system are provided for traffic shaping and bandwidth scaling in a high speed internetworking device. A slot time wheel mechanism is provided for traffic rate control and a credit/debit mechanism is provided for traffic shaping and scaling. The high speed traffic scaler and shaper incorporates a programmable slot time wheel, a traffic scaler state machine, a traffic shaper parameter table and a traffic scaler processor. The traffic scaler processor incorporates a traffic queue allocation manager, a queue priority arbiter, a port enable selector, a port priority arbiter and a DMA channel arbiter. The traffic queue allocation manager and the queue priority, port priority and DMA channel arbiters are each controlled by a corresponding state machine. The parameters in the traffic shaper parameter table are dynamically updated for each logical queue and are used to enable the credit/debit mechanism.

Abstract: A memory interface for multi-port access to a memory unit, such as a static random-access memory (SRAM) device. The memory interface, which is generally adapted for a local area network (LAN) forwarding engine, provides single port read/write access to SRAM device, and arbitrates requests from the access interfaces to allocate bandwidth of the SRAM device among the requests. One embodiment allocates at least 50% of the bandwidth to a peripheral component interface (PCI) bus target interface and a PCI bus master interface, collectively. The arbitration logic may include a plurality of bandwidth control registers associated with respective access interfaces used to determine a permitted amount of bandwidth that an access interface is to have, wherein a request from an access interface is masked based on a value in its associated bandwidth control register. Arbitration can further allocate bandwidth using time division multiplexing.

Abstract: A sequence in which two or more of the data units enter the network node, via a specific one of the multiple ports, is recorded. And, the two or more of the data units are transmitted from the network node according to the recorded sequence. The method and system achieve the recording of sequence via the following. In response to an insertion of one of the two or more data units into a specific one of the multiple processor subsystems, the specific one of the multiple processor subsystems is associated with a specific one of the multiple ports by which the one of the two or more data units entered the network node, and any other of the multiple processor subsystems that are currently processing on any other of the two or more data units that entered the network node through the specific one of the multiple ports is noted.

Abstract: A method for improving the performance of an existing busoriented computer system with minimum or no design change to the existing hardware, bus protocol, or bus operation is disclosed. Specifically, the present invention improves the effective bandwidth of an existing bus architecture by creating multiple physical instantiations of the existing bus and directing traffic onto these different buses based on the type of bus operation being performed. This results in multiple components having the capability to simultaneously perform bus operations, therefore improving the effective bandwidth of the system. This invention also allows the components which are current being utilized in the existing bus architecture to be re-utilized with minimum additional external logic.

Abstract: A system and method for efficiently routing data within a network, such as a local area network. A search tree is utilized within the bridge/router in order to store addresses. The search tree is utilized by the router for more efficiently and more quickly determining where one or more received frames of data are to be transmitted within the network. Maintenance of the search trees is also provided so that new addresses may be added to the search trees and addresses may be deleted from the search trees. The search trees are developed by partitioning the addresses into bit groups.

Abstract: A character recognition system including a timing subsystem, comprising a base oscillator or clock, and timing circuits driven by the base clock to provide a plurality of timing pulses for timing the operation of the entire system. The timing circuits are governed in part by delay circuits which are in turn controlled by the amplitude and location of peak signals derived from scanning earlier pulses.