Memorize Quickly the OSI and TCP IP Models with Mapped PDU

This lesson will help CISSP candidates (and hopefully others) to understand and memorize quickly the OSI, TCP/IP, and PDU models as presented in the ISC2 CBK Domain 4, Communication and Network Security.

The PDU isn’t really a model, it’s just a reference to the data that goes along with the models. PDU stands for protocol data unit. OSI stands for open systems interconnect. I’m going to assume for this video that you’re somewhat familiar with, and have read, the chapter that deals with the OSI model.

As a refresher, the OSI model is a reference point, it’s not exact science. It’s a concept that was developed to promote something called interoperability.

A mnemonic is simply a word pattern that helps you to memorize something.

It starts with the physical layer – bit pushers, dumb devices like cables and hubs. Then comes the Datalink layer – network cards; think MAC addresses, switches... Then the Network layer – routers; then the Transport layer – think transmission of data; then the Session layer – establishing and maintaining a connection; then the Presentation layer – think of this as the machine readable layer, as in decoding the information, and finally the Application layer – this is the program that uses the information and actually enables users to do what they need.

To memorize the PDU, simple write the phrase “big feet point straight downward”.

[marcosrwr]

Finally I could memorize that! Thanks!

[thisisalotofwork]

What are the N's in your PDU reference for? Network? That makes things more confusing. The rest of them make sense, but I am not sure what those represent.

[kennethsarfo]

This is the worst!!! You are better off understanding the concept and applying it