On 10/04/2018 11:07 AM, Eric Smith via cctalk wrote:
The Ethernet I and II standards are available from Bitsavers:
     http://bitsavers.trailing-edge.com/pdf/xerox/ethernet/

Cool.

From the preface of _The Ethernet_ Version 2.0: Version 2.0 of the Ethernet specification reflects the experience of the three corporations in designing equipment to the Version 1.0 specification. Version 2.0 includes network management functions and better defines the details of the physical channel signalling.

Okay.  Intriguing.

Version 2.0 is upward compatible with Version 1.0. Equipment designed to the two specifications is interoperable.

My brain is having some trouble unpacking and understanding "upward compatible". - I always think that it should be "new version is /downward/ compatible with the old version" or "the old version is /upward/ compatible with the new version".

It's also stumbling on "the two specifications is interoperable". Is that "the (version) two specification is interoperable (with the version one specification)" or "the two specification(s) /are/ interoperable"? This might not make much difference. But my brain trips on are they truly 100% interoperable (as in extra fields in version 2 that version 1 ignores) or is it a case of version 1 only understand version 1 and version 2 is able to pretend to be version 1 when talking to version 1?

Sort of like a crude diagram:

v1  <--->| v2
v1 |<--->| v2
v1 |<--->  v2

Which of the three is it?

I'll have to check out the documentation on Bitsavers. Thank you for the link.



--
Grant. . . .
unix || die

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