Chapter 1 content

Question 1

What is network communication?

Answer 1

Communication between terminal devices through a computer network, e.g. computer-computer, file transfer connected using router, computer downloads file from server

Question 2

Describe the information transfer process

Answer 2

1. Information is sent via a terminal device
2. The data is then capsulated by a header/footer to form a new packet(data/information)
3. The data is sent through the gateway router(router connects computer to internet) which connects the 4. router to the internet
4. To the gateway router of the device, the data is being sent to, and this data is decapsulated
5. And the data then gets to the other terminal device (i.e.computer), and get payload out(packet)

Question 3

What is a data communication network made up of and what is its function?

Answer 3

Routers, switches, switches, firewalls, access controllers (ACs), access points (APs), PCs, network printers and servers and all function to implement data communication

Question 4

What is a switch?

Answer 4

-Layer 2 device
-Closest device to end users,
-Used to access network and switch data frames

Question 5

What is a router? What are its functions?

Answer 5

-Layer 3 device
-Forward packet from one subnet to another
-Isolate broadcast domains, maintain routaing table and running routing protocols
-Select routes and forward IP packets
-Implement WAN access and network address translation
-Connect layer 2 networks established through switches

Question 6

What are firewalls and what are their functions?

Answer 6

A network security device ensures communication between two networks.

Functions:
-Isolate networks of different security levels
-Access control via security policies
-User Identity authentification
-Remote access
-Data encryption and VPN services
-Network address translation

Question 7

Categorize networks into their categories.

Answer 7

-LAN (Local area network): Is a network that consists of computers, network devices and servers within a geographical area, typically an office or home

-MAN (Metropolitan area network): Is a network that consists of computers, network devices and servers within a municipality or government provincial private lines

-WAN (Wide area network): This network consists of computers, network devices and servers within a country or globally, typically the internet.

Question 7

What is a wireless device?

Answer 7

Wireless network, typical is network:
-First is Fat AP, usually for homes, in router there is Fat AP (Access points), and there is a lot of management
-Second is AC (Access controls) to control AP and these provide signals for many users and not much management

Question 8

What is network topology?

Answer 8

The structure of the network, how they are connected

Question 9

Draw and describe the different network topologies and their disadvantages.

Answer 9

-Star network, central node which other nodes are directly connected to
-Bus network, end devices are connected to the bus, if two devices communicate then the bus is full, and other nodes cannot communicate
-Ring network, one link is corrupted, many hubs need to be used for communications, if two links are corrupted, then the whole network will be shut down
-Tree network, if links at the top are disconnected then the network is disrupted
-Full Mesh network, very reliable, any two nodes have a link, so if one link is corrupted then you can communicate with another,too many links
-Partial sorts the issue of the full mesh
-Combined network topology, which combines all the system