Abstract: A packet switching device having a central shared memory and a number of medium access controllers each coupled to a communications medium to exchange data packets therewith, and a controller coupled to each medium access controller via a data path to exchange data packets with the media access controller. The controller has a number of data path controllers each connected to each medium access controller via a separate and like portion of the data path to exchange a corresponding portion of the data packets with the medium access controller. The data path controllers each have a number of buffers each connected to one of the medium access controllers to which the data path controller is connected, to hold the portion of the data packets exchanged with the corresponding medium access controller.

Abstract: A packet switching device having a central shared memory and a number of medium access controllers each coupled to a communications medium to exchange data packets therewith, and a controller coupled to each medium access controller via a data path to exchange data packets with the media access controller. The controller has a number of data path controllers each connected to each medium access controller via a separate and like portion of the data path to exchange a corresponding portion of the data packets with the medium access controller. The data path controllers each have a number of buffers each connected to one of the medium access controllers to which the data path controller is connected, to hold the portion of the data packets exchanged with the corresponding medium access controller.

Abstract: A distributed memory switching hub interconnecting heterogeneous local area networks operating at different transmission speeds for receiving, storing and forwarding frames of data. The distributed memory switching hub employs a distributed memory architecture in which memory storage for frames of data received and to be transmitted is located at each low speed LAN port of the distributed memory switching hub. A distributed memory architecture renders unnecessary the need for a central programmable processor or shared common memory to store and forward frames received by the distributed memory switching hub.

Abstract: A flexible, policy-based, mechanism for managing, monitoring, and prioritizing traffic within a network and allocating bandwidth to achieve true quality of service (QoS) is provided. According to one aspect of the present invention, a method is provided for managing bandwidth allocation in a network that employs a non-deterministic access protocol, such as an Ethernet network. A packet forwarding device receives information indicative of a set of traffic groups, such as: a MAC address, or IEEE 802.1p priority indicator or 802.1Q frame tag, if the QoS policy is based upon individual station applications; or a physical port if the QoS policy is based purely upon topology. The packet forwarding device additionally receives bandwidth parameters corresponding to the traffic groups.

Abstract: A packet switching device having a central shared memory and a number of medium access controllers each coupled to a communications medium to exchange data packets therewith, and a controller coupled to each medium access controller via a data path to exchange data packets with the media access controller. The controller has a number of data path controllers each connected to each medium access controller via a separate and like portion of the data path to exchange a corresponding portion of the data packets with the medium access controller. The data path controllers each have a number of buffers each connected to one of the medium access controllers to which the data path controller is connected, to hold the portion of the data packets exchanged with the corresponding medium access controller.

Abstract: A network interconnect device and message exchange protocol for forwarding data among packet forwarding devices are provided. According to one aspect of the present invention, data is forwarded between a first and second packet forwarding device coupled to an interconnect device. The interconnect device receives a menu message from the first packet forwarding device that indicates one or more types of data that are awaiting transmission on the first packet forwarding device. Based upon the menu message, the interconnect device transmits an order message selecting a type of data of the one or more types of data awaiting transmission to the first packet forwarding device. The interconnect device receives a message from the first packet forwarding device containing data of the type selected by the order message. The interconnect device then forwards the data to the second packet forwarding device.

Abstract: A message exchange protocol for interconnecting packet forwarding devices through an intermediate network interconnect device is provided. According to one aspect of the present invention, a method is provided for communicating data between packet forwarding devices. The presence of an interconnect device that is coupled between a first packet forwarding device and a second packet forwarding device is detected by recognizing a configuration sequence, for example. After the link between the interconnect device and the first packet forwarding device is established, the first packet forwarding device receives a command from the interconnect device requesting the types of data that are pending on the first packet forwarding device. Responsive to the command, the first packet forwarding device transmits a "menu" including information indicating the availability of one or more types of data that are awaiting transmission to the interconnect device.

Abstract: A plurality of video dynamic random access memory devices (VRAMs) distributed among low speed local area network ports of a distributed memory switching hub interconnecting heterogeneous local area networks operating at different transmission speeds for receiving, storing and forwarding frames of data. The distributed memory switching hub employs a distributed memory architecture in which VRAM devices located at each low speed LAN port of the distributed memory switching hub store frames of data received or to be forwarded. The VRAM device is comprised of serial access memory (SAM) coupled to and transmitting frames of data with a high speed internal data bus at the same speed of the data bus and dynamic random access memory (RAM) coupled to and transmitting frames of data with a low speed local area network at the same speed of the low speed local area network. The SAM and RAM operate asynchronously with respect to each other to provide simultaneous bidirectional transfer of frames of data between them.

Abstract: A translation engine for translating frames of data from one frame format to another frame format in the same manner as an IEEE 802.1D MAC layer transparent bridge as required when transferring frames of data between interconnected heterogeneous local area networks. The translation engine is comprised of a variable length data pipeline capable of maintaining a constant synchronous data stream comprising frames of data from the input to the output of the data pipeline, without introducing any gaps in the data stream caused by removing fields of a frame, or causing the data stream to halt by inserting fields of a frame during translation of a frame from one frame format to another frame format.

Abstract: A translation engine for translating frames of data from one frame format to another frame format in the same manner as an IEEE 802.1D MAC-layer transparent bridge as required when transferring frames of data between interconnected heterogeneous local area networks. The translation engine is comprised of a variable length data pipeline capable of maintaining a constant synchronous data stream comprising frames of data from the input to the output of the data pipeline, without introducing any gaps in the data stream caused by removing fields of a frame, or causing the data stream to halt by inserting fields of a frame during translation of a frame from one frame format to another frame format.