Patent ID: 11870590
Assignee: MELLANOX TECHNOLOGIES, LTD.
Field: Digital communication (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 9:
10. Data transfer apparatus, comprising:
a first network interface controller (NIC), which couples a first computer to a network and is configured to transmit a sequence of data packets, including at least a first packet and a second packet transmitted subsequently to the first packet, from a first computer over a network to a second computer in a single remote direct memory access (RDMA) data transfer transaction of a given type, selected from among first and second types of transactions,
wherein in the first type of transaction, the first computer specifies a memory range to which data from the packets are to be written by the second computer, whereas in the second type of transaction, the memory range is specified by a work request submitted from a host processor to a network interface controller (NIC) of the second computer; and
a second NIC, which couples the second computer to the network and is configured to send, upon receipt of the second packet without previously having received the first packet, a negative acknowledgment (NAK) packet over the network to the first computer, indicating that the first packet was not received,
wherein the first NIC is configured to select a retransmission mode responsively to the type of the transaction, such that in response to the transaction being of the first type, the first NIC retransmits the first packet in response to the NAK packet without retransmitting the second packet, and in response to the transaction being of the second type, the first NIC retransmits both the first and second packets in response to the NAK packet, and to retransmit one or more of the data packets in response to the NAK packet in accordance with the selected retransmission mode.