摘要:
A novel method of flow control in a multiport data switching system having a decision making engine for controlling data forwarding between receive ports and at least one transmit port. Data blocks representing received data packets are placed in a plurality of data queues to be processed by the decision making engine. The data queues allocated to the receive ports are monitored to produce a flow control threshold signal for a selected data queue to indicate a heavy traffic condition of a receive port corresponding to the selected data queue. For example, the flow control threshold signal may indicate that the receive port is close to an overflow condition. Monitoring of a selected data queue may be performed by comparing a write pointer indicating a memory location for writing the data blocks into the selected data queue with a read pointer indicating a memory location for reading the data blocks from the selected data queue. The flow control threshold signal is produced when a predetermined number of memory entries in the data queue is occupied.
摘要:
A novel method of overflow data handling in a multiport data switching system having a decision making engine for controlling data forwarding between receive ports and at least one transmit port. Data blocks representing received data packets are placed in data queues corresponding to the receive ports. The data queues are transferred to logic circuitry for processing in accordance with a prescribed algorithm. Then, a forwarding decision is made to determine the transmit port. An overflow bypass is provided to allow at least a portion of a data block to bypass the logic circuitry, when at least one of the data queues is in an overflow state. For example, pointers indicating memory locations for storing the corresponding received data packets may be transferred via the overflow bypass when the overflow state is detected.
摘要:
A gigabit network node having a media access controller outputting data frames at gigabit rates uses multiple 100 MB/s media interface links coupled to a physical interface to enable implementation of a gigabit network using low cost data links. A modified reconciliation layer, also referred to as a media interface, receives a data frame from a gigabit MAC and selectively stores the received packet data into one of a plurality of transmit buffers associated with the respective 100 MB/s media interface links, according to a path selection arbitration logic in the media interface. The path selection arbitration logic may operate according to an equal priority scheme, where each received data frame is routed according to a round-robin scheme. A high priority/low priority scheme may also be used by the path selection arbitration logic, where data frames identified as high priority are temporarily stored in a high priority transmit buffer, and then forwarded to a selected one of the transmit buffers associated with a corresponding 100 MB/s media interface link before outputting data frames from a low priority buffer.
摘要:
An integrated multiport switch operating in a packet switched network utilizes an internal rules checker (IRC) to process data frames. The IRC employs a modular, pipelined architecture that enables data frames to be processed simultaneously, thereby increasing data throughput.
摘要:
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) employs a modular architecture that enables data frames to be processed simultaneously and increase data throughput. The IRC further generates a port vector, and thereby, outputs a forwarding descriptor that instructs Port Vector FIFO logic (PVF) on how to process the data frame.
摘要:
Apparatus and method for more precise controlling of congestion on a network, provides for remote controlling of a remote station on the network by a local station to configure the remote station into a remote loopback configuration. With the remote station thus configured, the local station is then able to determine the link latency of the link, during auto-negotiation, for example. Provided with the link latency, a congestion control algorithm in the local station may be adjusted to account for the link latency to better control the input data streams by controlling when the congestion relieving control signal, such as a PAUSE frame, is transmitted to the remote station to inhibit transmission and relieve congestion.
摘要:
An arrangement in a processor circuit for concurrently executing a plurality of instructions. An instruction control unit concurrently supplies a plurality of instruction addresses to an instruction memory. Each clock cycle, the instruction memory receives one instruction address from the instruction control unit based on a count value and selectively fetches and outputs corresponding to the received instruction address. An instruction decoder decodes, each clock cycle, the instruction output from the instruction memory the preceding clock cycle while identifying a memory address and an instruction operation for each fetched instruction. A memory interface, based on the count value, selectively supplies to an external memory, each clock cycle, one of the supplied memory addresses and identified by the instruction decoder for the respective fetched instructions. A logic unit, based on the count value also, selectively executes, each clock cycle, the instruction operation for the corresponding fetched instruction using memory data retrieved from the supplied memory address. The instruction control unit has program counter circuits that respectively output the instruction addresses. An instruction controller generates program instruction control signals for each of the program counter circuits in response to a corresponding instruction sequence.
摘要:
Interpacket delay times are modified in full-duplex Ethernet network devices by calculating for each network station a delay interval based on a time to transmit a data packet at the network rate and a calculated time to transmit the data packet at a desired transmission rate. The network station waits the calculated delay time following a packet transmission before transmitting the next data packet, ensuring that the overall output transmission rate of the network station corresponds to the assigned desired transmission rate. The desired transmission rate is received as a media access control (MAC) control frame from a network management entity, such as a switched hub. Hence, each network station operates at the desired transmission rate, minimizing the occurrence of congestion and eliminating the necessity of PAUSE frames.
摘要:
A Gigabit network node having a media access controller outputting packet data at Gigabit rates uses multiple 100 MB/s physical layer links coupled to a physical interface having a data router to enable implementation of a Gigabit network using low cost data links. A modified reconciliation layer, also referred to as a multi-Media Independent Interface (m-MII) selectively transmits at least a portion of the packet data from the MAC onto the plurality of physical layer links. The physical m-MII interface may output separate packet data on separate physical layer links to increase the effective data transmission rate, may output the same packet data on multiple transmission paths to improve quality of service by establishing redundant data links, or any combination thereof. Priority channels may also be provided on selected physical layer links to provide quality of service and cost of service options within an Ethernet work group environment.
摘要:
A Gigabit network node having a media access controller outputting packet data at Gigabit rates uses multiple 100 MB/s media interface links coupled to a physical interface to enable implementation of a Gigabit network using low cost data links. A modified reconciliation layer, also referred to as a media interface, receives a data packet from a Gigabit MAC and divides the received data packet into multiple data segments having a prescribed length. The multiple segments are output on the multiple media interface links according to a prescribed output protocol, enabling a corresponding media interface at the destination station to recompile the data packet from the received segments from the multiple transmission paths. The transmission of the segments upon multiple transmission paths provides an efficient load balancing of data traffic among the multiple transmission paths.