Abstract: In one embodiment, a method includes sending a first flow control signal to a first stage of transmit queues when a receive queue is in a congestion state. The method also includes sending a second flow control signal to a second stage of transmit queues different from the first stage of transmit queues when the receive queue is in the congestion state.

Abstract: In one example, a network device comprising a first chassis of a multi-chassis link aggregation group (MC-LAG) having three or more chassis, comprises one or more network interfaces configured to receive a packet to be forwarded using the MC-LAG, and a control unit configured to determine whether the packet was received from a device outside of the MC-LAG, when the packet was received from the device outside of the MC-LAG, add data to the packet that identifies the first chassis as a source of the packet for the MC-LAG, and forward the packet via at least one of the network interfaces. In this manner, chassis of the MC-LAG can prevent forwarding of the packet to the source of the packet for the MC-LAG, based on the data that identifies a source of the packet for the MC-LAG.

Abstract: In one example, a network device comprising a first chassis of a multi-chassis link aggregation group (MC-LAG) having three or more chassis, comprises one or more network interfaces configured to receive a packet to be forwarded using the MC-LAG, and a control unit configured to determine whether the packet was received from a device outside of the MC-LAG, when the packet was received from the device outside of the MC-LAG, add data to the packet that identifies the first chassis as a source of the packet for the MC-LAG, and forward the packet via at least one of the network interfaces. In this manner, chassis of the MC-LAG can prevent forwarding of the packet to the source of the packet for the MC-LAG, based on the data that identifies a source of the packet for the MC-LAG.

Abstract: In one embodiment, a method includes sending a first flow control signal to a first stage of transmit queues when a receive queue is in a congestion state. The method also includes sending a second flow control signal to a second stage of transmit queues different from the first stage of transmit queues when the receive queue is in the congestion state.

Abstract: In one embodiment, a method includes sending a first flow control signal to a first stage of transmit queues when a receive queue is in a congestion state. The method also includes sending a second flow control signal to a second stage of transmit queues different from the first stage of transmit queues when the receive queue is in the congestion state.

Abstract: An output circuit, included in a device, may determine counter information associated with a packet provided via an output queue managed by the output circuit. The output circuit may determine that a latency event, associated with the output queue, has occurred. The output circuit may provide the counter information and time of day information associated with the counter information. The output circuit may provide a latency event notification associated with the output queue. An input circuit, included in the device, may receive the latency event notification associated with the output queue. The input circuit may determine performance information associated with an input queue. The input queue may correspond to the output queue and may be managed by the input circuit. The input circuit may provide the performance information associated with the input queue and time of day information associated with the performance information.

Abstract: An output circuit, included in a device, may determine counter information associated with a packet provided via an output queue managed by the output circuit. The output circuit may determine that a latency event, associated with the output queue, has occurred. The output circuit may provide the counter information and time of day information associated with the counter information. The output circuit may provide a latency event notification associated with the output queue. An input circuit, included in the device, may receive the latency event notification associated with the output queue. The input circuit may determine performance information associated with an input queue. The input queue may correspond to the output queue and may be managed by the input circuit. The input circuit may provide the performance information associated with the input queue and time of day information associated with the performance information.

Abstract: A system may include receiving a packet, of a packet stream, including control tags in a header portion of the packet and classifying each of the control tags into a category selected from a set of possible categories. The set of possible categories may include an unambiguous interposable (UI) category that is assigned to a control tag that corresponds to an unambiguous parsing interpretation and that is interposable within a sequence of the control tags, and an ambiguous interposable (AI) category that is assigned to a control tag in which the control tag has an ambiguous parsing interpretation and in which the control tag is interposable within the sequence of the control tags. The method may further include determining parsing operations to perform for the packet based on the classified categories of the control tags and based on the packet stream of the packet.

Abstract: A system may include receiving a packet, of a packet stream, including control tags in a header portion of the packet and classifying each of the control tags into a category selected from a set of possible categories. The set of possible categories may include an unambiguous interposable (UI) category that is assigned to a control tag that corresponds to an unambiguous parsing interpretation and that is interposable within a sequence of the control tags, and an ambiguous interposable (AI) category that is assigned to a control tag in which the control tag has an ambiguous parsing interpretation and in which the control tag is interposable within the sequence of the control tags. The method may further include determining parsing operations to perform for the packet based on the classified categories of the control tags and based on the packet stream of the packet.

Abstract: A system provides congestion control and includes multiple queues that temporarily store data and a drop engine. The system associates a value with each of the queues, where each of the values relates to an amount of memory associated with the queue. The drop engine compares the value associated with a particular one of the queues to one or more programmable thresholds and selectively performs explicit congestion notification or packet dropping on data in the particular queue based on a result of the comparison.

Abstract: A system selectively drops data from queues. The system includes a drop table that stores drop probabilities. The system selects one of the queues to examine and generates an index into the drop table to identify one of the drop probabilities for the examined queue. The system then determines whether to drop data from the examined queue based on the identified drop probability.

Abstract: A system that processes single stream multicast data includes multiple queues, a dequeue engine, and/or a queue control engine. The queues temporarily store data. At least one of the queues stores single stream multicast data. A multicast count is associated with the single stream multicast data and corresponds to a number of destinations to which the single stream multicast data is to be sent. The dequeue engine dequeues data from the queues. If the data corresponds to the single stream multicast data, the dequeue engine examines the multicast count associated with the single stream multicast data and dequeues the single stream multicast data based on the multicast count. The queue control engine examines one of the queues to determine whether to drop data from the queue and marks the data based on a result of the determination.

Abstract: In one embodiment, a method includes sending a first flow control signal to a first stage of transmit queues when a receive queue is in a congestion state. The method also includes sending a second flow control signal to a second stage of transmit queues different from the first stage of transmit queues when the receive queue is in the congestion state.

Abstract: A system may include receiving a packet, of a packet stream, including control tags in a header portion of the packet and classifying each of the control tags into a category selected from a set of possible categories. The set of possible categories may include an unambiguous interposable (UI) category that is assigned to a control tag that corresponds to an unambiguous parsing interpretation and that is interposable within a sequence of the control tags, and an ambiguous interposable (AI) category that is assigned to a control tag in which the control tag has an ambiguous parsing interpretation and in which the control tag is interposable within the sequence of the control tags. The method may further include determining parsing operations to perform for the packet based on the classified categories of the control tags and based on the packet stream of the packet.

Abstract: A system that processes single stream multicast data includes multiple queues, a dequeue engine, and/or a queue control engine. The queues temporarily store data. At least one of the queues stores single stream multicast data. A multicast count is associated with the single stream multicast data and corresponds to a number of destinations to which the single stream multicast data is to be sent. The dequeue engine dequeues data from the queues. If the data corresponds to the single stream multicast data, the dequeue engine examines the multicast count associated with the single stream multicast data and dequeues the single stream multicast data based on the multicast count. The queue control engine examines one of the queues to determine whether to drop data from the queue and marks the data based on a result of the determination.

Abstract: In one embodiment, a method includes sending a first flow control signal to a first stage of transmit queues when a receive queue is in a congestion state. The method also includes sending a second flow control signal to a second stage of transmit queues different from the first stage of transmit queues when the receive queue is in the congestion state.

Abstract: A network device may receive a packet including control tags in a header portion of the packet and may extract candidate tags from the control tags in the header portion of the packet. The network device may compress, using a first lookup table, the candidate tags to obtain keys corresponding to the candidate tags, where each of the keys is represented in a compressed format relative to the corresponding candidate tags. The network device may further determine a final key based on the first keys and determine a priority class for the packet based on a lookup operation of the final key into a second lookup table. The network device may further write the packet, or a reference to the packet, to a selected priority queue, of a number of priority queues, where the priority queue is selected based on the determined priority class.

Abstract: A system that processes single stream multicast data includes multiple queues, a dequeue engine, and/or a queue control engine. The queues temporarily store data. At least one of the queues stores single stream multicast data. A multicast count is associated with the single stream multicast data and corresponds to a number of destinations to which the single stream multicast data is to be sent. The dequeue engine dequeues data from the queues. If the data corresponds to the single stream multicast data, the dequeue engine examines the multicast count associated with the single stream multicast data and dequeues the single stream multicast data based on the multicast count. The queue control engine examines one of the queues to determine whether to drop data from the queue and marks the data based on a result of the determination.

Abstract: In one embodiment, a method, comprising receiving at a receive side of a physical link a request to suspend transmission of data from a queue within a transmit side of a first stage of queues and to suspend transmission via a path including the physical link, a portion of the first stage of queues, and a portion of a second stage of queues. The method includes sending, in response to the request, a flow control signal to a flow control module configured to schedule transmission of the data from the queue within the transmit side of the first stage of queues. The flow control signal is associated with a first control loop including the path and differing from a second control loop that excludes the first stage of queues.

Abstract: Systems and methods of various embodiments provide mechanisms to support synchronous and asynchronous transactions. Distinct encodings allow an instruction to choose whether to perform any operation synchronously or asynchronously. Separate synchronous and asynchronous result registers hold the data returned in the most recent replies received for synchronous and asynchronous transaction requests, respectively. A status bit indicates whether an asynchronous transaction request is currently outstanding.