1.3.3 Networks

Question 1

Network

Answer 1

The name given to two or more computers connected together with the ability to transmit data between each other.

There are two main types of networks:
-Local area network
-Wide area network

Question 2

Local Area Network (LAN)

Answer 2

The name given to a network which is spread over a small geographical area or a single site.

Question 3

Wide Area Network (WAN)

Answer 3

A network which is spread over a large geographical area.

Question 4

Two types of network

Answer 4

Physical topology - the physical layout of the wires and components which form the network. (bus, star and mesh)

Logical topology - the layout which shows how data flows.

Question 5

Physical Bus topology

Answer 5

In a bus topology all terminals (devices) are connected to a backbone cable , the ends which are plugged into a terminator which absorbs the signals when they reach the end, to prevent interference.

Advantages:
-Relatively inexpensive to setup
-does not require any additional hardware

Disadvantages:
- If backbone cable fails all the terminals(devices) get disconnected. The entire network gets disconnected
- As traffic increases performance decreases
-All computers can see the data transmitted making it not secure..

Question 6

Physical Star topology

Answer 6

Star topology uses a central node usually a switch to direct data through the network. MAC address which are unique to each device are used to identify each device on the network.

Advantages:
-Performance stays consistent even with heavy network traffic
-If one cable fails only the terminal that was connect to it will disconnect to the network
-Transmits data faster giving better performance than bus topology.
-Easy to add new stations(devices to the network by adding cable)
-No data collisions

Disadvantages:
-Expensive due to switch and cabling
-If the central switch fails the rest of the network fails.

Question 7

Physical mesh topology

Answer 7

In a mesh topology every node is connected to every other node. Mesh topology is usually found in wireless technology such as wi-fi.

Advantages:
-If using a wireless network there is no cable cost
-As the number of nodes increases the reliability and speed of network becomes better.
-Nodes are automatically incorporated
-Nodes do not go through a central node which increases the speed.

Disadvantage:
-If using a wireless network, devices
with wireless capability (which
increases cost) must be purchased
-If using a wired network, a large
quantity of cable is required
compared to other network
topologies like bus and star. This is
expensive
-Maintaining the network is difficult

Question 8

Protocols

Answer 8

A protocol is a set of rules defining how two computers communicate with each other.
Protocols are standard so that all devices have a designated method of communicating
with each other, regardless of manufacturer.