You have set up an Internet based FTP server, where people can upload and download files. In terms of the OSI model, what is the highest layer used during the FTP sessions.

A. Application
B. Presentation
C. Session
D. Transport
E. Internet
F. Data Link
G. Physical

Answer: A

Explanation:

The application layer is the highest layer (layer 7) of the OSI model, and is reserved for
end user applications. Since FTP is itself an application, layer 7 is the highest layer used.

Incorrect Answers:

B, C, D, E, F, G. In any given FTP session, all of these layers will be used at some point
but they are incorrect because the question asked for the highest layer used by FTP.