Abstract: A method for packet generation includes designating a group of one or more ports, from among multiple ports of one or more network elements, to perform the packet generation. A circular packet path, which traverses one or more buffers of the ports in the group, is configured. A burst of one or more packets is provided to the group, so as to cause the burst of packets to repeatedly traverse the circular packet path. A packet stream, including the repeated burst of packets, is transmitted from one of the ports.

Abstract: A method for circuit design automation includes appending a non-synthesizable input having a unique identifier to HDL code that specifies a physical input of the circuit. For the physical components in the circuit to which a signal from the physical input is to propagate, corresponding non-synthesizable components are appended, having respective identifiers assigned responsively to the unique identifier of the non-synthesizable input, to the HDL code that specifies the physical components. The design is verified by simulating operation of the circuit using the HDL code, including both the physical and non-synthesizable inputs and components. After verifying the design, a netlist synthesis tool automatically generates a netlist of the circuit including the physical inputs and components while omitting the non-synthesizable inputs and components.

Abstract: A method for communication includes receiving and forwarding packets in multiple flows to respective egress interfaces of a switching element for transmission to a network. For each of one or more of the egress interfaces, in each of a succession of arbitration cycles, a respective number of the packets in each of the plurality of the flows that are queued for transmission through the egress interface is assessed, and the flows for which the respective number is less than a selected threshold to a first group, while assigning the flows for which the respective number is equal to or greater than the selected threshold are assigned to a second group. The received packets that have been forwarded to the egress interface and belong to the flows in the first group are transmitted with a higher priority than the flows in the second group.

Abstract: Communication apparatus includes a plurality of interfaces for receiving and transmitting data packets from and to a network and a memory, which receives and stores context data with respect to multicast groups. Packet processing circuitry establishes reliable connections over the network with the receiving nodes in the multicast groups, and upon receiving from a packet source on the network an incoming unicast packet containing multicast data and containing multicast metadata that identifies a multicast group, sends an acknowledgment of the incoming unicast packet to the packet source, reads the context data from the memory with respect to the identified multicast group, and transmits multiple outgoing unicast packets containing the multicast data via respective egress interfaces to the receiving nodes in the multicast group over the reliable connections.

Abstract: A method for circuit design automation includes appending a non-synthesizable input having a unique identifier to HDL code that specifies a physical input of the circuit. For the physical components in the circuit to which a signal from the physical input is to propagate, corresponding non-synthesizable components are appended, having respective identifiers assigned responsively to the unique identifier of the non-synthesizable input, to the HDL code that specifies the physical components. The design is verified by simulating operation of the circuit using the HDL code, including both the physical and non-synthesizable inputs and components. After verifying the design, a netlist synthesis tool automatically generates a netlist of the circuit including the physical inputs and components while omitting the non-synthesizable inputs and components.

Abstract: A switch includes multiple physical ports and forwarding circuitry. The physical ports are configured to receive and send packets over a network. The forwarding circuitry is configured to assign first port numbers to the physical ports, and second port numbers to temporary ports defined in addition to the physical ports, to receive a packet having a destination address via a physical port, to select, based on the destination address, an egress port number for the packet from among the first and second port numbers, to forward the packet to a physical port corresponding to the egress port number if the egress port number is one of the first port numbers, and, if the egress port number is one of the second port numbers, to map a temporary port associated with the egress port number to a mapped physical port and to forward the packet to the mapped physical port.

Abstract: Communication apparatus includes multiple interfaces configured to be connected to a packet data network for receiving and forwarding of data packets of multiple types. A memory is coupled to the interfaces and configured as a buffer to contain packets received through the ingress interfaces while awaiting transmission to the network via the egress interfaces. Packet processing logic is configured to maintain multiple transmit queues, which are associated with respective ones of the egress interfaces, and to place both first and second queue entries, corresponding to first and second data packets of the first and second types, respectively, in a common transmit queue for transmission through a given egress interface, while allocating respective spaces in the buffer to store the first and second data packets against separate, first and second buffer allocations, which are respectively assigned to the first and second types of the data packets.

Abstract: Communication apparatus includes multiple interfaces connected to a packet data network, and a memory coupled to the interfaces and configured as a buffer to contain packets received through ingress interfaces while awaiting transmission to the network via respective egress interfaces. Packet processing logic is configured, upon receipt of a test packet through an ingress interface of the apparatus, to allocate a space in the buffer for storage of a single copy of the test packet, to replicate and transmit sequentially multiple copies of the stored copy of the test packet through a designated egress interface, to receive an indication of a number of copies of the test packet that are to be transmitted, and responsively to the indication, to terminate replication of the test packet and release the allocated space in the buffer.

Abstract: Communication apparatus includes a plurality of interfaces for receiving and transmitting data packets from and to a network and a memory, which receives and stores context data with respect to multicast groups. Packet processing circuitry establishes reliable connections over the network with the receiving nodes in the multicast groups, and upon receiving from a packet source on the network an incoming unicast packet containing multicast data and containing multicast metadata that identifies a multicast group, sends an acknowledgment of the incoming unicast packet to the packet source, reads the context data from the memory with respect to the identified multicast group, and transmits multiple outgoing unicast packets containing the multicast data via respective egress interfaces to the receiving nodes in the multicast group over the reliable connections.

Abstract: A method for communication includes receiving and forwarding packets in multiple flows to respective egress interfaces of a switching element for transmission to a network. For each of one or more of the egress interfaces, in each of a succession of arbitration cycles, a respective number of the packets in each of the plurality of the flows that are queued for transmission through the egress interface is assessed, and the flows for which the respective number is less than a selected threshold to a first group, while assigning the flows for which the respective number is equal to or greater than the selected threshold are assigned to a second group. The received packets that have been forwarded to the egress interface and belong to the flows in the first group are transmitted with a higher priority than the flows in the second group.

Abstract: A method for packet generation includes designating a group of one or more ports, from among multiple ports of one or more network elements, to perform the packet generation. A circular packet path, which traverses one or more buffers of the ports in the group, is configured. A burst of one or more packets is provided to the group, so as to cause the burst of packets to repeatedly traverse the circular packet path. A packet stream, including the repeated burst of packets, is transmitted from one of the ports.

Abstract: A method for communication includes receiving and forwarding packets in multiple flows to respective egress interfaces of a switching element for transmission to a network. For each of one or more of the egress interfaces, in each of a succession of arbitration cycles, a respective number of the packets in each of the plurality of the flows that are queued for transmission through the egress interface is assessed, and the flows for which the respective number is zero are assigned to a first group, while the flows for which the respective number is non-zero are assigned to a second group. The received packets that have been forwarded to the egress interface and belong to the flows in the first group are transmitted with a higher priority than the flows in the second group.

Abstract: A method for communication includes, in a network node that includes a plurality of ports, specifying for a given destination address at least one Adaptive Routing (AR) group. The at least one AR group includes two or more ports over which packets destined to the given destination address are to be adaptively routed. A packet destined to the given destination address is received at the network node, via one of the ports serving as an ingress port. An egress port is adaptively selected for the packet, from the ports in the at least one AR group but excluding the ingress port over which the packet was received. The packet is routed to the selected egress port.

Abstract: A method for communication includes receiving and forwarding packets in multiple flows to respective egress interfaces of a switching element for transmission to a network. For each of one or more of the egress interfaces, in each of a succession of arbitration cycles, a respective number of the packets in each of the plurality of the flows that are queued for transmission through the egress interface is assessed, and the flows for which the respective number is zero are assigned to a first group, while the flows for which the respective number is non-zero are assigned to a second group. The received packets that have been forwarded to the egress interface and belong to the flows in the first group are transmitted with a higher priority than the flows in the second group.

Abstract: Communication apparatus includes multiple interfaces connected to a packet data network, and a memory coupled to the interfaces and configured as a buffer to contain packets received through ingress interfaces while awaiting transmission to the network via respective egress interfaces. Packet processing logic is configured, upon receipt of a test packet through an ingress interface of the apparatus, to allocate a space in the buffer for storage of a single copy of the test packet, to replicate and transmit sequentially multiple copies of the stored copy of the test packet through a designated egress interface, to receive an indication of a number of copies of the test packet that are to be transmitted, and responsively to the indication, to terminate replication of the test packet and release the allocated space in the buffer.

Abstract: Communication apparatus includes multiple interfaces configured to be connected to a packet data network for receiving and forwarding of data packets of multiple types. A memory is coupled to the interfaces and configured as a buffer to contain packets received through the ingress interfaces while awaiting transmission to the network via the egress interfaces. Packet processing logic is configured to maintain multiple transmit queues, which are associated with respective ones of the egress interfaces, and to place both first and second queue entries, corresponding to first and second data packets of the first and second types, respectively, in a common transmit queue for transmission through a given egress interface, while allocating respective spaces in the buffer to store the first and second data packets against separate, first and second buffer allocations, which are respectively assigned to the first and second types of the data packets.

Abstract: A method in a network element includes processing input packets using a set of two or more functions that are defined over parameters of the input packets. Each function in the set produces respective interim actions applied to the input packets and the entire set produces respective end-to-end actions applied to the input packets. An end-to-end mapping, which maps the parameters of at least some of the input packets directly to the corresponding end-to-end actions, is cached in the network element. The end-to-end mapping is queried with the parameters of a new input packet. Upon finding the parameters of the new input packet in the end-to-end mapping, an end-to-end action mapped to the found parameters is applied to the new input packet, without processing the new input packet using the set of functions.

Abstract: A method in a network element that includes multiple interfaces for connecting to a communication network includes receiving via an ingress interface packets that are not allowed to undergo re-routing and that are addressed to a destination via a first egress interface. The packets are forwarded via the first egress interface when there is a valid path from the first egress interface to the destination. When there is no valid path from the first egress interface to the destination, a second egress interface is selected from a group of multiple egress interfaces that have respective paths to the destination and are assigned to packets for which re-routing is allowed, and the packets are forwarded via the second egress interface until recovering a path to the destination.

Abstract: A switch includes multiple physical ports and forwarding circuitry. The physical ports are configured to receive and send packets over a network. The forwarding circuitry is configured to assign first port numbers to the physical ports, and second port numbers to temporary ports defined in addition to the physical ports, to receive a packet having a destination address via a physical port, to select, based on the destination address, an egress port number for the packet from among the first and second port numbers, to forward the packet to a physical port corresponding to the egress port number if the egress port number is one of the first port numbers, and, if the egress port number is one of the second port numbers, to map a temporary port associated with the egress port number to a mapped physical port and to forward the packet to the mapped physical port.

Abstract: A method for communication includes, in a network node that includes a plurality of ports, specifying for a given destination address at least one Adaptive Routing (AR) group. The at least one AR group includes two or more ports over which packets destined to the given destination address are to be adaptively routed. A packet destined to the given destination address is received at the network node, via one of the ports serving as an ingress port. An egress port is adaptively selected for the packet, from the ports in the at least one AR group but excluding the ingress port over which the packet was received. The packet is routed to the selected egress port.