Chapter 1: Questions 7, 14, and 17
Question 7
How do local area networks (LANs) differ from metropolitan area networks (MANs), wide area networks (WANs), and backbone networks (BNs)?
Answer:
A Local Area Network (LAN) is a group of microcomputers or terminals located in the same general area.
A Backbone Network (BN) is a large central network that connects most everything on a single company site.
A Metropolitan Area Network (MAN) encompasses a city or county area.
A Wide Area Network (WAN) spans cities, states, or national boundaries.
Question 14
Explain how a message is transmitted from one computer to another using layers.
Answer: -
When a message is transmitted from one computer to another through these seven layer protocols are wrapped around the data, the layers in the network use a formal language or protocol that is a set of instructions of what the layer will do to the message, these protocols are labeled or encapsulated onto the data. Think of the protocols as layers of paper with a message that only the individual layer understands. The application layer is the application software used by the network user.
The transport layer is responsible for obtaining the address of the end user (if needed), breaking a large data transmission into smaller packets (if needed), ensuring that all the packets have been received, eliminating duplicate packets, and performing flow control to ensure that no computer is overwhelmed by the number of messages it receives.
The network layer takes the message generated by the application layer and if necessary, breaks it into several smaller messages. It then addresses the message(s) and determines their route through the network, and records message accounting information before passing it to the data link layer.
The data link layer formats the message to indicate where it starts and ends, decides when to