Networking Concepts and Applications

Week 1 Homework : Questions

Question 7: How do local area networks (LANs) differ from metropolitan area networks (MANs), wide area networks (WANs), and backbone networks (BNs)?

One of the key differences between different network types is their geographical scope. A local area network, or LAN, is made up of a smaller group of computers linked together and located in the same small area such as a room, a floor or a building. A backbone network, or BN, is a larger network which connects multiple LANs, WANs, MANs or other BNs together and can range from a few hundred feet to miles in size. Metropolitan area networks, or MANs, normally range in size from a few miles up to thirty miles and LANs and BNs from different areas to each other as well as to WANs. Wide area networks, or WANs, can be hundreds or thousands of miles in size and connect MANs and BNs across these distances.

Question 14: Explain how a message is transmitted from one computer to another using layers.

The message is first created at the application layer using a software application. This software translates the message based on the protocol being used to transfer the message and places the necessary information along with the message into a Protocol Data Unit (PDU) which is also known as a ‘packet’. This packet is then passed on to the Transport Layer.
The transport layer, using its own Transmission Control Protocol, or TCP, takes the packet from the application layer and places it in a TCP packet along with whatever additional data the TCP segment requires, and passes it along to the Network Layer.
The Network Layer, as with the previous layers, has its own protocols. In this case we’ll use the Internet Protocol, or IP. IP determines the next destination as the message is routed through the network, places the TCP packet inside an IP packet along