Hewlett-packard Company

Michael I Thompson

Paul T Congdon

John L Burnett

Frank Fiduccia, Deceased

K Monroe Bridges

Paul R Zimmer

Robert D Snyder

A method and apparatus are presented for an improved data transferring technique between a network and a computing system. A network adapter implements a data transfer from a network to the memory of a destination computing system, accumulating a checksum of all data transferred. The dedicated hardware allows data to be transferred through it and a checksum to be accumulated without intervention by the processor of the destination computing system. Software corrections can generate a checksum of the header data and then generate a net checksum by subtracting the header checksum from the gross checksum accumulated by the dedicated hardware, thus achieving the desired result with minimal intervention by the processor of the destination computing system.

Calculation of network data check sums by dedicated hardware with

A computing system is connected to a network. The computing system includes a network adapter and a main memory. The network adapter receives from the network a network packet having a plurality of headers. The network adapter inserts at least one pad byte within one of the plurality of headers to cause the plurality of headers in the network packet to be aligned along predetermined multi-byte boundaries. For example, the multi-byte boundaries are four-byte boundaries. After inserting the at least one pad byte, the network adapter forwards the network packet to the main memory.

Network adapter for inserting pad bytes into packet link headers based

A system implements checksumming of a network packet to be sent over a network. A processor constructs the network packet within a main memory. The network packet is transferred from the main memory to a packet storage memory within a network adapter. During the transfer, the network adapter calculates a checksum for the network packet. The network adapter then inserts the checksum into the network packet within the packet storage memory. The network adapter then sends the network packet to the network. In order to calculate the checksum for the network packet, hardware within the network adapter 'snoops' an internal bus within the network adapter as the network packet is transported to the packet storage memory. Also, a checksum header is prepended to the network packet which includes control information for checksumming. This control information includes, for example, an indication whether the network adapter is to calculate a checksum and a specification of what data in the network packet is to be checksummed. The control information may additionally include a location within network packet where the checksum is to be inserted.

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Rocklin, CA, United States of America

Michael I Thompson