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

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

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

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

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

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

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

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

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

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