53 results about "TCP offload engine" patented technology

A TCP Offload Engine (TOE) device includes a state machine that performs TCP / IP protocol processing operations in parallel. In a first aspect, the state machine includes a first memory, a second memory, and combinatorial logic. The first memory stores and simultaneously outputs multiple TCP state variables. The second memory stores and simultaneously outputs multiple header values. In contrast to a sequential processor technique, the combinatorial logic generates a flush detect signal from the TCP state variables and header values without performing sequential processor instructions or sequential memory accesses. In a second aspect, a TOE includes a state machine that performs an update of multiple TCP state variables in a TCB buffer all simultaneously, thereby avoiding multiple sequential writes to the TCB buffer memory. In a third aspect, a TOE involves a state machine that sets up a DMA move in a single state machine clock cycle.

The present invention defines a new protocol for communicating with an offload engine that provides Transmission Control Protocol (“TCP”) termination over a Fibre Channel (“FC”) fabric. The offload engine terminates all protocols up to and including TCP and performs the processing associated with those layers. The offload protocol guarantees delivery and is encapsulated within FCP-formatted frames. Thus, the TCP streams are reliably passed to the host. Additionally, using this scheme, the offload engine can provide parsing of the TCP stream to further assist the host. The present invention also provides network devices (and components thereof) that are configured to perform the foregoing methods. The invention further defines how network attached storage (“NAS”) protocol data units (“PDUs”) are parsed and delivered.

Certain embodiments of the invention may be found in a method and system for performing a SCSI read operation via a TCP offload engine. Aspects of the method may comprise receiving an iSCSI read command from an initiator (118). Data may be fetched from a buffer based on the received iSCSI read command. The fetched data may be zero copied from the buffer to the initiator (118) and a TCP sequence may be retransmitted to the initiator. The method may further comprise checking if the zero copied fetched data is a first frame in an iSCSI protocol data unit and if the buffer is posted. The retransmitted TCP sequence may be processed and the fetched data may be zero copied into an iSCSI buffer, if the buffer is posted.

Various aspects of a method and system for transmission control protocol (TCP) traffic smoothing are presented. Traffic smoothing may comprise a method for controlling data transmission in a communications system that further comprises scheduling the timing of transmission of information from a TCP offload engine (TOE) based on a traffic profile. Traffic smoothing may comprise transmitting information from a TOE at a rate that is either greater than, approximately equal to, or less than, the rate at which the information was generated. Some conventional network interface cards (NIC) that utilize TOEs may not provide a mechanism that enables traffic shaping. By not providing a mechanism for traffic shaping, there may be a greater probability of lost packets in the network.