ethernet and switches, was Re: [rescue] Mozilla Firefox

Eric Dittman dittman at
Fri Apr 23 14:35:53 CDT 2004

> > Not when it was known as SASI.  As for the protocol itself, look at the
> > problems with multiple LUNs, vendor-specific extensions for non-disk
> > devices, etc. that cause incompatibilities and the need for blacklists
> > and whitelists in the driver and application code.  Even though there
> > are better storage methods available, we still use SCSI because it 
> > works
> > despite the workarounds that sometimes are necessary.
>    True, but SASI was the crufty, proprietary Shugart-designed 
> interconnect.  When they grabbed it and turned it into SCSI, a fair 
> number of changes were made, such that SCSI is largely incompatible 
> with SASI.  They are related, but we can't really say they're the same 
> thing.

Yes, but look at where Ethernet actually started (even before DIX).  The
working groups have made a lot of changes to Ethernet over the years and
GigE is vastly changed from the original spec.  I think it's fair to say
that GigE is no longer the CSMA/CD network of old.

It's gone from a shared radio link with a small number of nodes to a
switched copper or fibre link with a huge number of nodes.  There are
some very basic concepts that are still there, but to judge the latest
Ethernet based on the original Ethernet does do an injustice.  They are
both Ethernet in name only.  You can make the GigE work in a reduced-
feature mode for backward compatibility, but that's like using a 64-bit
133MHz PCI card in a 32-bit 33MHz PCI slot.  You can do it, but it's
not the ideal way to operate.  If you are using a GigE card connected
to a 10M hub it will work but it will be much slower than using the
GigE card connected to a GigE switch that supports Jumbo packets.
Eric Dittman
dittman at

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