Network And Internet
Network
A network is defined as a system of computers connected together through a single transmission technology.
The connected computers can communicate with each other through receiving or sending information.
Internet
The internet is defined as a set of networks, connected by routers which manage traffic between different computers.
Classification of Networks
The network can be classified by following: 1. Size 2. Connectivity 3. Medium 4. Mobility
By Size
According to the size, there are 2 classifications.
1. LAN
(Local Area Network): It covers a small area such as a building.
2. WAN
(Wide Area Network): It covers large areas such as cities or countries.
By Connectivity
According to connectivity, there are 2 classifications. 1. Point-to-Point 2. Broadcast
Point-to-Point
This comprises of 2 topologies. 1. Star: In this topology, computers are connected to a central hub. 2. Tree: In this topology, computers are connected in such a way that the structure appears like a tree.
Broadcast
This comprises of 2 technologies 1. Satellite or Radio: In this technology, computers are connected through satellite through radio waves. 2. Ring: In this technology, computers are connected in a ring structure.
By Medium
By medium, network are classified as such: 1. Copper Wire 2. Co-axial cable 3. Optical Fiber 4. Radio Waves
These can differ from each other depending on following parameters: - speed - range - topology - Installation and maintenance cost
By Mobility
There are 2 types of networks. 1. Fixed networks 2. Mobile networks
Issues
- Location and Tracking
- Semi persistent connections
- Complex administration
- Billing as devices
- Users move across the networks
Networks in Daily Life
network is being used in daily life as follows:
Business
- Advertisements
- Production
- Shipping
- Planning
- Billing
- Accounting
Homes
network can be used to control home appliances through phone.
Government
Following use network for communication. 1. Federal 2. Local 3. Military
Education
We have libraries or LMS systems which we can access from home.
Complexity of Network Systems
Following are the reasons why network are complex,
Many Technologies Exist
There are multiple standards developed by multiple companies which result into incompatible technologies.
No Single Underlying Theory or Model
Instead of having a theory, we have similarities or differences between the network hardware and software.
Models Are either way Too Simple or Complex
Either the models are way to simple that it is hard to spot differences or either they are way too much complicated and are not simplified enough.
No Simple or Uniform Terminology
There is no uniform terminology used for same features.
Different technologies with similar features use different terminologies.
Mastering of Complexity
Concentrate on Understanding the Concept
An example is: instead of looking at how different protocols handle congestion, look at what congestion itself is.
Learning the Network Terminology
Focus on the breath, not the depth.
Understand the illustrations.
New terminology is introduced with new concepts so learning those can make life easier.