[Simh] Comments WRT to IP vs ISO and OSI model

[Clem Cole]

On Tue, Oct 6, 2015 at 8:36 PM, Johnny Billquist <bqt at softjar.se> wrote:

> Right. I suspect Rich was actually thinking of the 7 layer OSI model,
> which DEC tried really hard to implement.
>
​insert >>eventually<< in there and I agree.

In the first few generations of DECnet, as Rich points out, DEC was no
different than anyone else and had a closed networking system and it was
not that clean.  By DECnet phase III many lessons had been learn and it
really was a nice subsystem.  However, I've always felt that one of the
failures of DECnet was the dogged adherence to ISO protocol later made them
ignore the "IP" part of the the Internet protocol for too long - because in
fact OSI did not really have it in its model.

By the time the ISO guys added intra-networking (network of networks - or
what I referred to as "Dave Clark's observation"), Metcalfe's law (the
value of a communications network is exponentally proportional to the
number of things connected to it)​ it was too late.   And by then the US
Gov had paid for enough IP/TCP implementations and there were so many on
the Internet that even IBM and Microsoft could not catch up (although they
too tried).




> (And no, TCP/IP do *not* follow the 7 layer OSI model.)
>
​Amen, not by a >>long<< shot.   You could sort of map it, and we all tried
to explain the IP stack in those terms, but you are so right.

That said, one of the problems with the OSI model was it did not do a good
job with the "network of network" concept which was what made the Internet
take off because it enabled Metcalfe's law to be in effect.

It seems to obvious today, but at the time, it was not so clear.  A lot of
very smart people believed in closed networks.

Clem​
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20151006/198329b6/attachment.html>