Abstract:
A Software-Defined Networking (SDN) switch that includes external network ports for receiving external network traffic onto the SDN switch, external network ports for transmitting external network traffic out of the SDN switch, a Network Flow Switch (NFX) integrated circuit that has multiple network ports and that maintains a flow table, another NFX integrated circuit that has multiple network ports and that maintains a flow table, and a Network Flow Processor (NFP) circuit that maintains a flow table. The NFP circuit couples directly to a network port of the first NFX integrated circuit but does not couple directly to any network port of the second NFX integrated circuit. The NFP circuit sends a flow entry to one NFX integrated circuit along with an addressing label and the NFX integrated circuit uses the addressing label to determine that the flow entry is to be forwarded to the second NFX integrated circuit.
Abstract:
Incoming frame data is stored in a plurality of dual linked lists of buffers in a pipelined memory. The dual linked lists of buffers are maintained by a link manager. The link manager maintains, for each dual linked list of buffers, a first head pointer, a second head pointer, a first tail pointer, a second tail pointer, a head pointer active bit, and a tail pointer active bit. The first head and tail pointers are used to maintain the first linked list of the dual linked list. The second head and tail pointers are used to maintain the second linked list of the dual linked list. Due to the pipelined nature of the memory, the dual linked list system can be popped to supply dequeued values at a sustained rate of more than one value per the read access latency time of the pipelined memory.
Abstract:
A general purpose PicoEngine Multi-Processor (PEMP) includes a hierarchically organized pool of small specialized picoengine processors and associated memories. A stream of data input values is received onto the PEMP. Each input data value is characterized, and from the characterization a task is determined. Picoengines are selected in a sequence. When the next picoengine in the sequence is available, it is then given the input data value along with an associated task assignment. The picoengine then performs the task. An output picoengine selector selects picoengines in the same sequence. If the next picoengine indicates that it has completed its assigned task, then the output value from the selected picoengine is output from the PEMP. By changing the sequence used, more or less of the processing power and memory resources of the pool is brought to bear on the incoming data stream. The PEMP automatically disables unused picoengines and memories.
Abstract:
A method involving a Software-Defined Networking (SDN) switch. A packet is received onto a SDN switch via a NFX circuit. The NFX circuit determines that the packet matches no flow entry stored in any flow table in the NFX circuit and forwards the packet to a NFP circuit. The NFP circuit determines that the packet matches a first flow entry that applies to a relatively broad flow of packets stored in a flow table in the NFP circuit, generates a new flow entry that applies to a relatively narrow subflow of packets, and forwards the new flow entry to the NFX circuit that stores the new flow entry in a flow table in the NFX circuit. A subsequent packet is received onto the SDN switch via the NFX circuit and is switched using the new flow entry stored in the NFX circuit without forwarding the packet to the NFP circuit.
Abstract:
An egress packet modifier includes a script parser and a pipeline of processing stages. Rather than performing egress modifications using a processor that fetches and decodes and executes instructions in a classic processor fashion, and rather than storing a packet in memory and reading it out and modifying it and writing it back, the packet modifier pipeline processes the packet by passing parts of the packet through the pipeline. A processor identifies particular egress modifications to be performed by placing a script code at the beginning of the packet. The script parser then uses the code to identify a specific script of opcodes, where each opcode defines a modification. As a part passes through a stage, the stage can carry out the modification of such an opcode. As realized using current semiconductor fabrication process, the packet modifier can modify 200M packets/second at a sustained rate of up to 100 gigabits/second.
Abstract:
A Self-Timed Logic Entropy Bit Stream Generator (STLEBSG) outputs a bit stream having non-deterministic entropy. The bit stream is supplied onto an input of a signal storage ring so that entropy of the bit stream is then stored in the ring as the bit stream circulates in the ring. Depending on the configuration of the ring, the bit stream as it circulates undergoes permutations, but the signal storage ring nonetheless stores the entropy of the injected bit stream. In one example, the STLEBSG is disabled and the bit stream is no longer supplied to the ring, but the ring continues to circulate and stores entropy of the original bit stream. With the STLEBSG disabled, a signal output from the ring is used to generate one or more random numbers.
Abstract:
An island-based network flow processor (IB-NFP) integrated circuit includes islands organized in rows. A configurable mesh event bus extends through the islands and is configured to form a local event ring. The configurable mesh event bus is configured with configuration information received via a configurable mesh control bus. The local event ring involves event ring circuits and event ring segments. In one example, a packet is received onto a first island. If an amount of a processing resource (for example, memory buffer space) available to the first island is below a threshold, then an event packet is communicated from the first island to a second island via the local event ring. In response, the second island causes a third island to communicate via a command/push/pull data bus with the first island, thereby increasing the amount of the processing resource available to the first island for handing incoming packets.
Abstract:
A transactional memory (TM) receives a lookup command across a bus from a processor. The command includes a memory address. In response to the command, the TM pulls an input value (IV). The memory address is used to read a word containing multiple result values (RVs), multiple reference values, and multiple mask values from memory. A selecting circuit within the TM uses a starting bit position and a mask size to select a portion of the IV. The portion of the IV is a lookup key value (LKV). The LKV is masked by each mask value thereby generating multiple masked values. Each masked value is compared to a reference value thereby generating multiple comparison values. A lookup table generates a selector value based upon the comparison values. A result value is selected based on the selector value. The selected result value is then communicated to the processor via the bus.
Abstract:
A device that receives a packet descriptor and a queue number that indicates a queue stored within a memory unit, and in response determines an instantaneous queue depth of the queue. The instantaneous queue depth is used to determine a drop probability. The drop probability is used to randomly determine if the packet descriptor should be stored in the queue. The queue has a first queue depth range and a second queue depth range that do not overlap. A first drop probability is associated with the first queue depth range and a second drop probability is associated with the second queue depth range. The first drop probability is used when the queue depth is within the first queue depth range. The second drop probability is used with the queue depth is within the second queue depth range. The device includes a random value generator and a drop indicator generator.
Abstract:
A method for receiving a packet descriptor associated with a packet and a queue number indicating a queue stored within a memory unit, determining a priority level of the packet and an amount of free memory available in the memory unit. Applying a global drop probability to generate a global drop indicator and applying a queue drop probability to generate a queue drop indicator. The global drop probability is a function of the amount of free memory. The queue drop probability is a function of instantaneous queue depth or drop precedence value. The packet is transmitted whenever the priority level is high. When the priority level is low, the packet is transmitted when both the global drop indicator and the queue drop indicator are a logic low value. When the priority level is low, the packet is not transmitted when either drop indicator is a logic low value.