Which device acting as a translator is used to connect two networks or applications from Layer 4 up to Layer 7
of the ISO/OSI Model?

A.
Bridge

B.
Repeater

C.
Router

D.
Gateway

Explanation:
A gateway works at OSI Application layer, where it connects different types of networks; performs protocol and
format translations.
Incorrect Answers:
A: A bridge works at the data link layer, not the application layer.
B: A repeater works at the physical layer, not the application layer.
C: A router works at the transport layer, not the application layer.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 623