A system for protocol processing in a computer network has an intelligent
network interface card (INIC) or communication processing device (CPD)
associated with a host computer. The INIC provides a fast-path that
avoids protocol processing for most large multi-packet messages, greatly
accelerating data communication. The INIC also assists the host for those
message packets that are chosen for processing by host software layers. A
communication control block for a message is defined that allows DMA
controllers of the INIC to move data, free of headers, directly to or
from a destination or source in the host. The context is stored in the
INIC as a communication control block (CCB) that can be passed back to
the host for message processing by the host. The INIC contains
specialized hardware circuits that are much faster at their specific
tasks than a general purpose CPU. A preferred embodiment includes a trio
of pipelined processors with separate processors devoted to transmit,
receive and management processing, with full duplex communication for
four fast Ethernet nodes.