VISA: Netstation's Virtual Internet SCSI Adapter
Rod Van Meter
USC/ISI

Netstation is a new system architecture built around the concept of a
gigabit network as the system backplane.  Network-attached peripherals
(NAPs), including a frame buffer, camera, keyboard and disk drive, are
being prototyped or emulated.  Appropriate security mechanisms
(including Derived Virtual Devices, or DVDs), network protocols, and
OS APIs are being developed to efficiently support this new system
paradigm.

One goal of Netstation is to demonstrate that internet protocols can
serve as an effective communications base for NAPs.  To this end, we
are developing VISA, our Virtual Internet SCSI Adapter.  Implemented
under SunOS, VISA is one instantiation of the scsi_transport layer,
accepting SCSI commands prepared by the sd (SCSI disk) device driver
for transmission to the corresponding device.  I will describe the
software architecture, network protocols used, preliminary performance
numbers, lessons learned and work remaining on this portion of
the Netstation project.

Rod Van Meter has been institutionalized almost continuously since the
age of sixteen, first at the California Institute of Technology, then
at USC's Information Sciences Institute.  At ISI he held positions in
the Information Processing Center and the MOSIS project from 1986
until 1992, when he escaped to Japan to do SCSI interfaces for mass
storage peripherals.  In April of 1995 he was recaptured by ISI, where 
he is currently a computer scientist working on the Netstation
project in the computer networks division.