Lesson 3 - Computer Networking

Assalamualaikum and greetings.
Starting from today's update, some of the blog's update will be using English to enhance my English skills and preventing from misunderstanding the terms used. :)

In today's update, I will explains about some topics in Computer Networking such as:

A. Definition of Computer Network

B. Type of Network

C. Network Component

D. Networking Architecture

E. Network Topology

A. Definition of Computer Network

A computer network is a group of computer systems and other computing hardware devices that are linked together through communication channels to facilitate communication and resource-sharing among a wide range of users electronically.

B. Type of Network

1. Personal Area Network (PAN)

- Network of personal devices

- Example: Computer > Printer, Connection between mobile devices.

2. Local Area Network (LAN)

- Covers relatively small geographical area

- Example: at home, school, office

- Allows emails, accessing the internet, file exchange or printer sharing

3. Wide Area Network (WAN)

- Covers large geographical area

- Consists of two or more LAN connected using communication technology

- This mode of telecommunication allows a business to effectively carry out its daily function regardless of location. 

4. Metropolitan Area Network (MAN)

- Network designed to service a metropolitan area, a city or a country 

- Owned or provided by a city or network provider 

C. Network Component

1. Hots/End Nodes

- The data source and the data destination

- Examples: Personal Computers, Terminals, Workstations

2. Transmission Media

- For data transmission and control signals

- 2 ways: Bounded (wired) or unbounded (wireless)

3. Network Electronic Device

- Provide interface between different media transmitter or for different protocol

- To connect multiple network together or to connect computer or network to the internet 

- Example: Bridges, Routers, Hubs, Switches

4. Applications/Software

- Software in the network functions to ensure data is delivered at respective destination 

- The applications at the end nodes normally involves technique and protocols

- The protocol determines the rules and procedure to send data, terminate data, interpret data, present data and control mistakes

D. Network Architecture & Protocol

- Ensure interoperability between various devices and equipment made by different vendors

- Enable devices made by different companies to work or communicate with each other

- 2 types: 

Client/Server Networks:

- Client: Computers that request or utilize network resources

- Server: Processing the request by client

- Download: Retrieves file from server

- Upload: Transfer from client to server

Peer to Peer Networks:

- Have direct access to other devices attached to the network

- No central server

- Example: Infrared/Bluetooth between phones, iTunes

E. Network Topology

- The arrangement or mapping of the elements of a network, especially the physical (real) and logical (virtual) interconnections between nodes

- 2 types:

Physical:

1. Linear bus:

- Consists of central cable to which all devices are connected with a terminator at each end

- Data transmitted through the bus line from one device to the other

- Network cannot function when the bus line fails

- All nodes are connected to the linear cable

2. Ring:

- Each of the systems is connected to its respective neighbour forming a ring

- The main difference between the bus and ring is that the ring topology does not require termination

- The systems are connected all together in a loop, there is no beginning and end point as there is with the bus topology

- No terminator and no bounce back signal

3. Star:

- All networked devices are connected directly to the central device

- Data on a star network passes through the hub or concentrator before continuing to it destination

- The hub or concentrator manages and controls all functions of the network

4. Tree 

- Can incorporate structures such as ring, star and bus network in one large network

- It consists of groups of star-configured workstations connected to a linear bus backbone cable

- Allow for the expansion of an existing network, and enable schools to configure a network to meet their needs

5. Mesh

- Redundant physical connections to one another

- When the mesh network is a WAN or LAN that is divided into multiple subnets, routers make decisions about which of the multiple available paths will be taken

Logical

- The way that the data passes through the network from one device to the next without regard to the physical interconnection of the devices

- 2 ways:

a. Shared Media

- All the systems have the ability to access the physical layout whenever they need it

- Advantage: The systems have unrestricted access to the physical media

- Disadvantage: If two systems send information out on the wire at the same time, the packets collide and kill both packets

b. Token Based

- When a system needs to send out packets, it grabs token off of the wire, attaches it to the packets that are sent, and sends it back out on the wire

- As the token travels around the network, each system examines the token

- When the packets arrive at the destination systems, those systems copy the information off of the wire and the token continues its journey until it gets back to the sender

- When the packets arrive at the destination systems, those systems copy the information off of the wire and the token continues its journey until it gets back to the sender

- The ring topology best facilitates this requirement

That's all for lesson 3 contents update. In lesson 4, I will share about Cabling & Hardware. Mucha Gracias :)