Subject: Re: SCSI network
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Izaac <>
List: tech-kern
Date: 10/01/1999 13:16:54
On Fri, 1 Oct 1999, der Mouse wrote:

> I'm contemplating using SCSI interfaces as a networking medium.  Does
> anyone have any thoughts on where I should look for (a) convincing a
> machine that it should speak on other than ID 7 or (b) convincing a
> machine to respond as if it were a drive, ie, to respond to another
> device on the bus attempting to contact it?  If necessary I'm prepared
> to make the link asymmetric, with one of the hosts distinctly in
> control of what happens, though I'd prefer to avoid that.
> Oh, it is also important that both hosts be able to speak to disks on
> the bus.  (Yes, I do intend to make sure they use disjoint subsets of
> the drives present. :-)
> In case this is hardware-dependent, the machines I'm considering doing
> this with are SPARCstations (ELC, 1+, IPX); if necessary I can dedicate
> a Sun-3/60 to it.

This is something I've wanted to do for a very long time, but just
never got around to doing anything about.

Think about it.. All these guys are running around buying high speed,
high expense network cards and switches for their Beowulf clusters in
an  attempt to widen the bandwidth as much as possible.  Meanwhile,
there's already a high volume, high speed device communications method
very likely in use in every node of their cluster.. :)

I've been following these fellows and they seem to be on the ball:


IP Encapsulation in SCSI Driver

Randy Scott, Chris Frantz, and Alan Bork

Submitted to Dr. M. Sebern on 20 February 1997

As today's needs for more bandwidth increase, traditional low-cost
Ethernet devices operating at top speeds of 100Mbps may not be fast
enough. This project is designed to implement a high-speed IP-capable
link that can, with the right equipment, operate at close to 400Mbps
with a hardware cost of only about double that of high speed 100Mbps   
Ethernet (100Base-T, etc.).

This is to be accomplished using SCSI (the Small Computer System
Interface) to encapsulate IP datagrams and transmit the datagrams on
high-speed SCSI busses. This technology is primarily suited for
clusters of high-speed workstations that are in close physical
proximity to each other. Depending on the SCSI standard in use and the
cable type, the distance between workstations may be limited to as
little as 5 meters.
Our implementation focuses on the Linux platform, but the concepts
discussed in this document can easily be used to implement IP
encapsulated in SCSI on nearly any platform available.

Table of Contents

    Project Proposal
    Introduction to SCSI and Encapsulation
    Linux Implementation
        SCSI Driver Portion
        Network Driver Portion
        An Address Resolution Protocol
        User-mode Utilities for Configuring the SCSI Network
        Multiple Host Adapters in a System
        Test Plan and Results
        User's Manual
        Source Code
    Time Management Information

Last Modified: 20 February 1997

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