Cable Tester Question:

In a computer network, to enable data transmission from one computer to another, the network devices send messages in the form of packets. These packets are then added with the IP header by OSI reference model layer.

The Data Link Layer encapsulates each packet in a frame which contains the hardware address of the source and the destination computer. If a destination computer is on the remote network then the frames are routed through a gateway or router to the destination computer.