1. Fundamentals of Computer Networks
Introduction
1/17/2019
Eng.Haya Radwan Ghsoon

2. Network definition
a group of interconnected via cable and/wireless computers {two or more } and peripherals that is capable of sharing software and hardware resources between many users.
The purpose of a network is to enable the sharing of files and information between multiple systems.
1/17/2019
Eng.Haya Radwan Ghsoon

3. Network definition
Computer networks can be connected through cables. Such as : ◊ Ethernet cables. ◊ Phone lines. ◊ Wirelessly. Using wireless networking cards that send and receive data through the air.
1/17/2019
Eng.Haya Radwan Ghsoon

4. Data communication component
1/17/2019
Eng.Haya Radwan Ghsoon

5. The OSI model
An ISO (international standard organization ) that covers all aspects of a network communications is the open system interconnection(OSI) model.
an open system is a model that that allows any two different systems to communicate regardless of their underlying architecture.
the OSI model is not a protocol. It s model for understanding and designing a network architecture that is flexible ,robust and interoperable .
1/17/2019
Eng.Haya Radwan Ghsoon

6. The OSI model
The OSI model describes how information or data makes its way from application programs (such as spreadsheets) through a network medium (such as wire ) to another application program located on another network .
OSI model have 7 layers .
1/17/2019
Eng.Haya Radwan Ghsoon

7. OSI model layers
1/17/2019
Eng.Haya Radwan Ghsoon

8. OSI model layers
Eng.Haya Radwan Ghsoon
1/17/2019

9. Host& media layers
1/17/2019
Eng.Haya Radwan Ghsoon

10. Data flow through a network
Data flow in a network focuses on layers one, two , and three of the OSI model .
1/17/2019
Eng.Haya Radwan Ghsoon