Abstract: A number of network devices that control the communication of data frames between stations in a network are cascaded together to support a number of network stations. When a first device receives a data frame destined for a port on a second device, the first device transfers the data frame to the second device. The second device stores receive port information transmitted with the data frame and processes the data frame. If the second device identifies a congestion condition associated with processing the data, the second device transmits the receive port information back to the first device. The first device then performs a flow control-related operation on the port identified by the receive port information.

Abstract: A network device that controls the communication of data frames between stations includes a memory that stores frame pointers that point to addresses in an external memory. The data frames are stored in the external memory while the network device generates frame forwarding information for the respective data frames. The network device divides the available frame pointers into a number of categories corresponding to priorities associated with the data frames. When a frame is received at the network device, frame processing logic determines the priority of the data frame and checks whether a frame pointer corresponding to that particular priority is available. If no frame pointer corresponding to that priority is available, the multiport switch drops the data frame.

Abstract: A network device that controls the communication of data frames between stations includes a number of receive ports that receive data frames from the stations and a number of output ports that transmit the data frames to their intended destinations. The network device also includes a number of output queues that store data forwarding information associated with the received data frames. The network device partitions each of the output queues into a number of portions corresponding to the priorities supported by the network device. The number of portions and the size of each portion of the output queues may be programmable by the user.

Abstract: A system shapes traffic in a multiport network device. The system includes multiple token buckets and token bucket logic. The token buckets correspond to multiple priority queues of the multiple output ports of the network device and store one or more tokens. Each of the tokens corresponds to a byte of one or more received packets to be transmitted by the network device. The token bucket control logic generates the tokens for the token buckets. The token bucket control logic includes a master counter and multiple bucket counters. The master counter counts to a first count value and generates a done signal when the count reaches the first count value. The bucket counters, corresponding to the token buckets, receive the done signal, count to a second count value, and generate a token increment signal for storing a token in the corresponding token buckets when the count reaches the second count value.

Abstract: A network device includes a port filter, a first logic device, and a second logic device. The port filter receives a data frame and generates first data relating to the data frame. The first logic device generates second data for the received data frame. The second logic device receives the first data and determines whether the second data has been received. When the second data has not been received, the second logic prevents a transfer of different first data relating to a different data frame from the port filter.

Abstract: A host channel adapter configured for outputting packets according to InfiniBand™ protocol is implemented using partitioned link modules configured for performing selected link operations prior to outputting the packets. A pre-link module is configured for ordering work queue entries in an order based on determined service level and virtual lane priorities. The pre-link module outputs the ordered work queue entries to a transport service module configured for generating a transport layer header for the packets based on the respective work queue entries. Once the transport layer headers have been generated, a post-link module is configured for retrieval of the transport layer header and transport data and preparing the transmit data packets for transmission on the network by constructing the link layer fields. The post-link module outputs the transmit data packets based on the ordering and the flow control protocol for the appropriate virtual lanes.

Abstract: A computing node configured for communications on an InfiniBand™ network includes at least two host channel adapters configured for communications on the InfiniBand™ network, and at least one processor configured for controlling the communications of the two host channel adapters on the InfiniBand™ network. The host channel adapters communicate with the processor via an internal bus. The processor monitors communication operations by the host channel adapters on the InfiniBand™ network. If the processor detects that one of the host channel adapters is unable to complete the corresponding communication operations, the processor outputs a message requesting traffic destined to the one host channel adapter to be redirected to the remaining host channel adapter.

Abstract: An integrated network switch having multiple network switch ports for outputting data frames also includes a dequeuing system for selectively supplying a data frame for output according to a specified priority by an output switch port. The dequeuing system includes, for each network switch port, a plurality of priority queues configured for holding assigned data frames based on respective priorities assigned by switching logic. A weighted round robin scheduler supplies the assigned data frames held in the priority queues to the output switch port according to a prescribed weighted round robin scheduling. In addition, the dequeuing system uses token bucket filters for selectively passing the assigned data frames to the respective priority queues in a manner that ensures that a given data frame having a large size does not interfere with bandwidth reserved for high-priority packets requiring guaranteed quality of service.

Abstract: A system provides flow control in a network device. The system includes output queues that correspond to the output ports of the network device, a mask register, a first logic device, and a second logic device. Each of the output queues generates signals relating to the priority levels associated with the corresponding output port when at least a predetermined number of items are stored in the output queue. The mask register generates mask signals relating to the priority levels associated with a particular one of the output ports. The first logic device generates first flow control signals related to the priority levels associated with the particular output port based on the signals from the output queues and the mask signals associated with the priority levels and the particular output port. The second logic device generates a second flow control signal based on the first flow control signals from the first logic device.

Abstract: A multiport network device includes output ports, internal rules checking logic, a port filter, and input ports. The input ports receive data frames and transfer the data frames to the internal rules checking logic and the port filter. The internal rules checking logic determines the appropriate output ports for the frame. At potentially the same time, the port filter determines priority information for the frame. The port filter informs the internal rules checking logic when it has completed determining the priority information by transmitting an end-of-frame signal to the internal rules checking logic. In response, if the internal rules checking logic has completed determining the output ports for the frame, it assembles a frame descriptor corresponding to the frame and transmits the frame descriptor to the appropriate output port(s).

Abstract: A device for processing fluids includes a filter to capture a cell sample. The filter has a physical barrier to isolate the cell sample on the filter. Growth detection circuitry is associated with the filter. The growth detection circuitry identifies, through electrical measurements, a cell growth rate and hence the presence of live cells associated with the cell sample.

Abstract: A network switch includes network switch ports, and switching logic for determining the output port for each received layer 2 type data packet. The switching logic includes an address table configured for storing address-based switching decisions, a trunk table configured for assigning each network switch port to a corresponding identified trunk, and a trunk distribution table identifying the network switch ports assigned to each identified trunk. The switching logic determines the output port for each corresponding received layer 2 type data packet based on a corresponding switching decision for the received layer 2 type data packet, and based on selection of an entry in the trunk distribution table based on information within the received layer 2 type data packet. Hence, the network switch is able to perform trunk-based switching with minimal complexity, ensuring switching of data packets at the wire rate.

Abstract: A network switching system having a plurality of multiport switch modules and respective connected buffer memory devices assigns in each of the buffer memory devices a memory segment for storage of frame data from a corresponding one of the switch modules. Each memory device is divided into memory segments, also referred to as memory regions, wherein each memory segment is configured for storing frame data from a corresponding one of the switch modules. Hence, each switch module is configured for writing frame data, for a data frame received on one of the corresponding switch ports, into the corresponding assigned memory segment of each of the buffer memory devices. Any one of the switch modules can access any location of the buffer memory devices, enabling any one switch module to retrieve frame data from the buffer memory devices that was stored by another one of the switch modules.

Abstract: A network switch, configured for performing layer 2 and layer 3 switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols. The network switch uses the filter to detect the presence of an RFC 2205 compliant bandwidth reservation message from a host computer for reception by a router. The network switch is configured for selectively changing a requested quality of service specified in the bandwidth reservation message, based on a determined absence of available resources within the network switch.

Abstract: A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter within any one of the respective switch ports if backpressure is asserted by that port. The resetting of the retry counter within a port after assertion of backpressure affords the port a greater probability of winning collision mediation under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch.

Abstract: A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter for counting data packet transmission attempts within any one of the respective switch ports if backpressure is asserted by that port. A retry limit value for the retry counter is selectively modified according to programmed information to ensure that the total number of retrys does not exceed a maximum total number of allowable retrys. Resetting the retry counter within a port after assertion of backpressure affords the port a greater probability of transmitting earlier under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch. Selective modification of the retry limit value according to programmed information adds flexibility to vary the maximum total number of allowable retrys based upon current network switch conditions or the priority of a particular data packet.

Abstract: A network switching system having a plurality of multiport switch modules arranged in a cascaded sequence uses a signaling protocol that eliminates the necessity of storing a given network address within each of the address forwarding tables of the multiport switch modules. A network switch module, having an address forwarding table for storing switching information for respective stored network addresses and that receives a data packet, outputs a switching request to a subsequent one of the switch modules based on a determined absence of the destination address of the received data packet in the address forwarding table. Each of the successive network switch modules passes the switching request to the next switch module in the sequence upon a determined absence of the destination address in the corresponding address forwarding table.

Abstract: An apparatus and method are disclosed for maintaining free buffer information for a network switch. A first Random Access Memory (RAM), located on the network switch, functions to store values that indicate whether or not free buffers, located in a second RAM, are available for storing received data frames. An input logic is provided for placing values in the first RAM to indicate which free buffers are available for storing the data frames. When free buffers are required to store data frames, the output logic searches the first RAM and locates values that indicate available free buffers in the second RAM. The output logic then generates buffer pointers that address the locations of the free buffers in the second RAM. The buffer pointers that are generated are stored in a small capacity queue on the network switch to provide immediate availability to free buffers.

Abstract: A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter for counting data packet transmission attempts within any one of the respective switch ports if backpressure is asserted by that port. A retry limit value for the retry counter is modified to ensure that the total number of retrys does not exceed a maximum total number of allowable retrys. The resetting of the retry counter within a port after assertion of backpressure affords the port a greater probability of transmitting earlier under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch. The modification of the retry limit value ensures that the number of retrys for the port does not exceed industry standards.

Abstract: An integrated multiport switch operating in a packet switched network provides the capability to alter VLAN tags on a port by port basis. An internal rules checker (IRC) analyzes the header of a data frame to determine the frame type: untagged, VLAN-tagged, or priority-tagged. The IRC searches the untagged set table for the set of ports that are untagged for a particular VLAN. The IRC passes a forwarding descriptor that includes the frame type and a operational code (opcode) to a Port Vector FIFO logic (PVF). The PVF is responsible for creating a new opcode that instructs a dequeuing logic to add, remove, modify the VLAN tag, or send the frame unmodified. The opcodes generated by the PVF are individualized for each output port.