Computer Networking

1. Introduction to Computer Networks

A computer network is a collection of computers and devices connected together to share data,resources,and information

1.1. Components of Network

1. Computer (nodes)
2. Transmission media (cables or Wireless)
3. Networking devices (routers, switch etc)
4. Network software and protocol

1.2. Network Classification

LAN(Local Area Network)-Covers a small area like a home,office,or school.

MAN(Metropolitan Area Network)-Covers a city or town

WAN(Wide Area Network)-Covers large geographical areas (internet is the best example)

2. Network Topologies

A network topology-is the physical or layout of devices (computers,switches,routers) in a network and how they are connected.

2.1. Common Topologies

1.Bus-All devices share one cable

2.Star-Devices connect to a central switch

3.Ring -Data flows in a circular path

4.Mesh-Devices interconnect with many paths

5.Hybrid-Combination of topologies

2.2. Advantages and Disadvantages

1.Star is easy to manage

2.Mesh is highly reliable but expensive

3.Bus is cheap but unreliable

3. Network Models

A network model is a conceptual framework that explains how data moves from one device to another in a network

3.1. OSI Model (7 Layers)

1.physical-Transmission of bits.

2.Data Link-Error detection

3.Network-Routing and Ip addressing

4.Transport-Reliable delivery

5.Session-Session management

6.Presentation-Data formatting and encryption

7.Application-User interaction

3.2. TCP/IP Model

1.Network Access

2.Internet

3.Transport

4.Application

 Key point- Models help understand how data moves through a network