WEBVTT

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Isn't it a little sad that the Oasis model gets all the love, but this model really has the thanks

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of the Department of Defense when it comes to its creation.

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You see, the TCP IP architecture was worked out by the U.S. Department of Defense long before the Orci

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model was created.

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What the Department of Defense was working on was a way in which to really simplify the network communications

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and build a system that would be able to survive very fast changes, massive changes, potentially.

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What the Department of Defense really was working on was a system of computers that could stay communicating

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during a nuclear holocaust.

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That's right.

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This was during the arms race time.

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This is when the superpowers of the United States and Russia were, you know, attacking each other

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from at least verbally and building up nuclear armaments.

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And the Department of Defense was trying to build a system that could survive such an attack.

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And that gave rise to the modern Internet, of course, and the TCP IP modern architecture that we have

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today.

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Notice their model was very simplified, so it was four total layers.

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So they identified up at the top the application layer that became the application, the presentation

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in the session, layers of the OSA model.

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The host to host is like our transport layer.

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The Internet layer is like our network layer.

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And then they identified the physical and the data link together simply as network access.

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So you have three layers in one and then kind of a 1 to 1 mapping and then two layers in the network

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access layer.

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It can be sometimes beneficial to be able to coordinate these layers to the OCI model as some certification

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exams in our discipline will ask that silliness of you.

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I think that is a bit silly, but suffice it to say, let's know these layers.

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They actually predated the AOC model.