Abstract: A method for communication, includes routing unicast data packets among nodes in a network using respective Layer-3 addresses that are uniquely assigned to each of the nodes. Respective Layer-2 unicast addresses are assigned to the nodes in accordance with an algorithmic mapping of the respective Layer-3 addresses. The unicast data packets are forwarded within subnets of the network using the assigned Layer-2 addresses.

Abstract: A switch in a data network is configured to mediate data exchanges among network elements. The apparatus further includes a processor, which organizes the network elements into a hierarchical tree having a root node network element, vertex node network elements child node network elements that include leaf node network elements. The leaf node network elements are originate aggregation data and transmit the aggregation data to respective parent vertex node network elements. The vertex node network elements combine the aggregation data from at least a portion of the child node network elements, and transmit the combined aggregation data from the vertex node network elements to parent vertex node network elements. The root node network element is operative for initiating a reduction operation on the aggregation data.

Abstract: A method for communication, includes routing unicast data packets among nodes in a network using respective Layer-3 addresses that are uniquely assigned to each of the nodes. Respective Layer-2 unicast addresses are assigned to the nodes in accordance with an algorithmic mapping of the respective Layer-3 addresses. The unicast data packets are forwarded within subnets of the network using the assigned Layer-2 addresses.

Abstract: In a data network congestion control in a virtualized environment is enforced in packet flows to and from virtual machines in a host. A hypervisor and network interface hardware in the host are trusted components. Enforcement comprises estimating congestion states in the data network attributable to respective packet flows, recognizing a new packet that belongs to one of the data packet flows, and using one or more of the trusted components and to make a determination based on the congestion states that the new packet belongs to a congestion-producing packet flow. A congestion-control policy is applied by one or more of the trusted components to the new packet responsively to the determination.

Abstract: A network interface device for a host computer includes a network interface, configured to transmit and receive data packets to and from a network. Packet processing logic transfers data to and from the data packets transmitted and received via the network interface by direct memory access (DMA) from and to a system memory of the host computer. A memory controller includes a first memory interface configured to be connected to the system memory and a second memory interface, configured to be connected to a host complex of the host computer. Switching logic alternately couples the first memory interface to the packet processing logic in a DMA configuration and to the second memory interface in a pass-through configuration.

Abstract: A network interface device for a host computer includes a network interface, configured to transmit and receive data packets to and from a network. Packet processing logic transfers data to and from the data packets transmitted and received via the network interface by direct memory access (DMA) from and to a system memory of the host computer. A memory controller includes a first memory interface configured to be connected to the system memory and a second memory interface, configured to be connected to a host complex of the host computer. Switching logic alternately couples the first memory interface to the packet processing logic in a DMA configuration and to the second memory interface in a pass-through configuration.

Abstract: A method for communication in a packet data network that includes at least first and second subnets interconnected by multiple routers and having respective first and second subnet managers. The method includes assigning respective local identifiers to ports for addressing of data link traffic within each subnet, such that the first subnet manager assigns the local identifiers in the first subnet, and the second subnet manager assigns the local identifiers in the second subnet. The routers are configured by transmitting and receiving control traffic between the subnet managers and the routers. Data packets are transmitted between network nodes in the first and second subnets via one or more of the configured routers under control of the subnet managers.

Abstract: A method for communication in a packet data network including a subnet containing multiple nodes having respective ports. The method includes assigning respective local identifiers to the ports in the subnet, such that each port receives a respective local identifier that is unique within the subnet to serve as an address for traffic within the subnet that is directed to the port. In addition to the local identifiers, respective port identifiers are assigned to the ports, such that at least one of the port identifiers is shared by a plurality of the ports, but not by all the ports, in the subnet. The plurality of the ports are addressed collectively using the at least one of the port identifiers.

Abstract: A method for communication includes receiving a packet at a first node for transmission over a link to a second node. The data in the packet is divided into a sequence of cells of a predetermined data size. The cells have respective sequence numbers. The cells are transmitted in sequence over the link, while storing the transmitted cells in a buffer at the first node. The first node receives acknowledgments indicating the respective sequence numbers of the transmitted cells that were received at the second node. Upon receiving an indication at the first node that a transmitted cell having a given sequence number was not properly received at the second node, the stored cells are retransmitted from the buffer starting from the cell with the given sequence number.

Abstract: A method for communication includes allocating in a memory of a host device a contiguous, cyclical set of buffers for use by a transport service instance on a network interface controller (NIC). First and second indices point respectively to a first buffer in the set to which the NIC is to write and a second buffer in the set from which a client process running on the host device is to read. Upon receiving at the NIC a message directed to the transport service instance and containing data to be pushed to the memory, the data are written to the first buffer that is pointed to by the first index, and the first index is advanced cyclically through the set. The second index is advanced cyclically through the set when the data in the second buffer have been read by the client process.

Abstract: A method includes receiving in a network switch of a communication network communication traffic that originates from a source node and arrives over a route through the communication network traversing one or more preceding network switches, for forwarding to a destination node. In response to detecting in the network switch a compromised ability to forward the communication traffic to the destination node, a notification is sent to the preceding network switches. The notification is to be consumed by the preceding network switches and requests the preceding network switches to modify the route so as not to traverse the network switch.

Abstract: A method for communication includes receiving at a receiving node over a network from a sending node a succession of data packets belonging to a sequence of transactions, including at least one or more first packets belonging to a first transaction and one or more second packets belonging to a second transaction executed by the sending node after the first transaction, wherein at least one of the second packets is received at the receiving node before at least one of the first packets. At the receiving node, upon receipt of the data packets, data are written from the data packets in the succession to respective locations in a buffer. Execution of the second transaction at the receiving node is delayed until all of the first packets have been received and the first transaction has been executed at the receiving node.

Abstract: A method includes receiving in a network switch of a communication network communication traffic that originates from a source node and arrives over a route through the communication network traversing one or more preceding network switches, for forwarding to a destination node. In response to detecting in the network switch a compromised ability to forward the communication traffic to the destination node, a notification is sent to the preceding network switches. The notification is to be consumed by the preceding network switches and requests the preceding network switches to modify the route so as not to traverse the network switch.

Abstract: A method for communication, includes routing unicast data packets among nodes in a network using respective Layer-3 addresses that are uniquely assigned to each of the nodes. Respective Layer-2 unicast addresses are assigned to the nodes in accordance with an algorithmic mapping of the respective Layer-3 addresses. The unicast data packets are forwarded within subnets of the network using the assigned Layer-2 addresses.

Abstract: An interface device includes a first proxy interface configured to carry out first direct memory access (DMA) transactions initiated by an input/output (I/O) device and a second proxy interface configured to carry out second DMA transactions initiated by a storage drive. A buffer memory is coupled between the first and second proxy interfaces and configured to temporarily hold data transferred in the first and second DMA transactions. Control logic is configured to invoke the second DMA transactions in response to the first DMA transactions so as to cause the data to be transferred via the buffer between the I/O device and the storage drive.

Abstract: A method for data storage includes mapping a queue pair (QP) of a channel adapter to a specified Fiber Channel (FC) exchange for communication with a storage device. Upon receiving at the channel adapter from a host computer a storage command directed to the storage device, the storage command is executed by transmitting data packets over a switched network from the channel adapter to the storage device using the specified exchange and performing a remote direct memory access (RDMA) operation on the channel adapter using the mapped QP.

Abstract: In a data network congestion control in a virtualized environment is enforced in packet flows to and from virtual machines in a host. A hypervisor and network interface hardware in the host are trusted components. Enforcement comprises estimating congestion states in the data network attributable to respective packet flows, recognizing a new packet that belongs to one of the data packet flows, and using one or more of the trusted components and to make a determination based on the congestion states that the new packet belongs to a congestion-producing packet flow. A congestion-control policy is applied by one or more of the trusted components to the new packet responsively to the determination.

Abstract: An interface device includes a first proxy interface configured to carry out first direct memory access (DMA) transactions initiated by an input/output (I/O) device and a second proxy interface configured to carry out second DMA transactions initiated by a storage drive. A buffer memory is coupled between the first and second proxy interfaces and configured to temporarily hold data transferred in the first and second DMA transactions. Control logic is configured to invoke the second DMA transactions in response to the first DMA transactions so as to cause the data to be transferred via the buffer between the I/O device and the storage drive.

Abstract: A method for communication includes sending a pause frame from a first node to a second node over a communication link between the nodes. In response to the pause frame, one or more data frames are immediately transmitted from the second node to the first node upon receipt of the pause frame at the second node.

Abstract: A communication method in a network operating in accordance with a standard that allocates a given number of bits m for layer-2 addressing of nodes in the network. The method includes accepting at a layer-2 switch in the network an assignment to one or more nodes in the network of respective layer-2 extended addresses, each including n=m+k bits, k>0. A given data packet is received at the switch for forwarding. The given data packet includes a layer-2 destination address and a layer-3 destination address in accordance with the standard. The layer-3 destination address includes t bits, t?k. The given data packet is forwarded from the switch to one of the nodes by reading from the given data packet and combining the layer-2 destination address and k bits from the layer-3 destination address so as to reconstruct the n bits of the extended layer-2 address of the one of the nodes.