OSI versus TCP/IP Protocol stack

[jabw]

I'm still studying for my CCNA and in the books I'm using I found some annoying inconsistancy between the number of layers on the TCP/IP protocol stack compared to the OSI Reference Model
From CiscoPress: TCP/IP stack
Layer 1 and Layer 2 are combined into a Network Interface layer.
From McGrawHill (also used a lot by Boson):
Layer 1 = Physical layer and
Layer 2 = Data link layer.

So according to CiscoPress the TCP/IP protocol stack has 4 layers and according to McGrawHill it has 5 layers.

What's correct. (In terms of CCNA Exam criteria).

 

[JOAMON]

The TCP/IP is only four layers and the OSI is seven.

A All Application
P People Presentation
S Seem Session
T To Transport
N Need Network
D Double Data Link
P Pepperoni Physical

TCP/IP
Application is top 3 of OSI Application
Transport is Transport Transport
Internet is Network Innernet
Network is Data and Physical Network

 

[gwildfire]

Also remeber that the osi model is only a theoretical model, ands doesnt really exist. Its simply a guidline for porotocols to follow. Whereas the TCP/IP model is a real model based on that particulat protocol suite.

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