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<div class="moz-cite-prefix">Am 28.05.2013 18:51, schrieb Bob
Braden:<br>
</div>
<blockquote cite="mid:51A4E09E.5030501@isi.edu" type="cite"><br>
<br>
So what are the poor OSI devotees, who believe in One Network to
Rule them All, to do?
<br>
<br>
</blockquote>
<br>
The point is: The OSI model is a <b>reference model</b>. I
apologize, when I'm carrying cowls to Newcastle here, but it took me
sometime to accept this myself.<br>
<br>
There is no need to fit anything into the OSI model and - vice versa
- the OSI model may differ from reality.<br>
<br>
Sometimes, things are done twice. That's annoying. Sometimes, things
are missing, then it's a "problem".<br>
<br>
<blockquote cite="mid:51A4E09E.5030501@isi.edu" type="cite">We
IETFers are pragmatists, not layer model purists. (as illustrated
by our lack of
<br>
embarassment about splitting the layers with MPLS, IPsec, TLS,
etc.) We became careless and smudged over
<br>
the network/internetwork distinction. So, IETFers generally refer
to the Internetwork layer as the "network layer." Then the
Internet
<br>
protocol stack sort of looks like the OSI stack, and there is an
illusion that the OSI stack has something to do with reality.
<br>
<br>
If IP is the "network layer" (we are too lazy to say "internetwork
layer"), then what is the Ethernet? In IP land, it is a
subnet(work). But
<br>
for those who believe that IP is really our network layer, then
the next layer below IP was dubbed the Link Layer, because it
<br>
seems to correspond to the OSI Data Link Layer. That is the answer
to your question.
<br>
</blockquote>
<br>
However, we have to make sure that mechanism on the "IP
internetworking layer" and the "Ethernet network layer" do not
interfere.<br>
<br>
<br>
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