Answer:
In a broadcast network such as radio network for example a walkie talkie, the broadcasted transmission is received equally by all receivers indiscriminately which may lead to dissemination of classified information to an unauthorized receiver, therefore, the network layer is required is needed to ensure proper routing of the information
Similarly, when the all the broadcasters in one location are each trying to send messages to different receivers at another given location, there would be potential for network congestion and it would be difficult to send information through the network
When there is need for priority service the presence of a network layer is needed in the network
However, when the above functions performed by the network layer is not required, then, the network layer can be excluded, such as the communication between layers 4 - 7 of the OSI model
Explanation:
