Giganet developing VI/IP for NAS

By Richard R. Lee

Giganet, a company known for exploiting the advantages of the Virtual Interface (VI) architecture as a cluster and "server farm" interconnect (5,000+ nodes of its cLAN VI products have been shipped to date), has announced a new initiative called VI/IP. The technology takes advantage of VI's high throughput, low latency, and low CPU overhead, combined with standard Ethernet or Gigabit Ethernet IP networks.

With VI, applications can communicate with each other directly, bypassing the operating system and protocol stacks. Giganet is extending VI with its RapidFlow technology, which is designed to increase network performance by reducing congestion.

Initial shipments of a 1Gbps Ethernet host adapter card are expected early next year.

Giganet officials claim VI/IP can double application throughput while reducing the computing resources required by a factor of five. This is accomplished by using the VI protocol set, which requires 50 CPU instructions per I/O, versus the 7,000+ instructions that the full TCP/IP protocol stack requires.

VI/IP enables the connection of servers and NAS devices via the Virtual Interface architecture over IP networks.
Click here to enlarge image

The aim of the VI/IP standard, which has been submitted to the IETF, is to deliver increased performance to users who move data across corporate IT networks between host applications and network-attached storage (NAS) devices. Another potential advantage is a significant reduction in the cost and complexity associated with managing separate production networks for LAN and NAS traffic.

In a related move, Giganet has formed a partnership with NAS leader Network Appliance. The two companies announced a joint venture to develop the Direct Access File System (DAFS), an adaptation of Giganet's VI-based file system, for use in Network Appliance's NAS "filers." (For more information on DAFS, see

To facilitate the wide adoption of both VI/IP and DAFS, Giganet and its partners (Cisco, Network Appliance, and others) will provide open APIs for application developers to optimize performance in VI/IP environments.


VI is a breath of fresh air in the world of IP networking. Its use of a shortened, optimized protocol stack, along with remote DMA techniques, overcomes the inefficiencies of the seven-layer TCP/IP protocol stack. Giganet and its partners have joined forces to remove some major performance bottlenecks in NAS architectures and, eventually, IP-based storage area networks (SANs).

This article was originally published on September 01, 2000