Intelligent network storage interface system and devices

An interface device (22) is connected to a host computer (20) by an I/O bus (40) and provides hardware and processing mechanisms for accelerating data transfers between a network (25, 28) and a storage unit (66, 70), while controlling the data transfers by the host (20). The interface device includes hardware circuitry (52, 58, 60) for processing network packet headers, and can use a dedicated fast-path for data transfer between the network (25, 28) and the storage unit (66, 70), the fast-path set up by the host(20). The host CPU (30) and protocol stack (38) avoids protocol processing for data transfer over the fast-path, freeing host bus bandwidth, and the data need not cross the I/Obus (40), freeing I/O bus bandwidth. The storage unit (66, 70) may include RAID or other multiple drive configurations and may be connected to the interface device (22) by a parallel channel such as SCSI or by a serial channel such as Ethernet of Fibre Channel. The interface device (22) contains a file cache (80) that stores data transferred between the network and the storage unit, with organization of data in the interface device file cache (80) controlled by a file system (23) on the host. Additional interface devices (303, 310, 420, 490) may be connected to the host (20) via the I/O bus (40), with each additional interface device (303, 310, 420, 490) having a file cache controlled by the host file system (23), and providing additional network connections (305, 313, 414, 416, 418, 420, 492, 494) and/or being connected to additional storage units (308, 315). Realtime audio and video communication can also be provided when the interface device is coupled by an audio/video interface (666,677) to appropriate communication devices, such as microphone (670, 680), a speaker (668, 678), a camera (674, 684) and/or a display (672, 682).