network standards & protocols

Network Protocol & StandardsNETWORKING ECE2225

VIZIONEER STUDIOS

Sub-Topics Covering Today

What Is The OSI Model Layers Of The OSI Model The Purpose Of The Layered Model Seven Layers Of The OSI Model in Details Questions

What Is The OSI Model?SECTION 1

OSI Model

Breaking Down The Acronym OSI Stands ForOpen System Interconnect

OSI Model

Why Mention The OSI Model? The Description For The OSI Model Is Both A

Layered And Abstract Description For Communications And Computer Network Protocol Design.

In Case You’re Wondering, Abstract In Computer Language Is The Separation Of Ideas From Specific Instances At Work

OSI Model

In The Acronym OSI, The I Stands For Interconnect.

Reason Being Model Is A Set Of Standard Specifications That Allows Various Computer Platforms To Communicate With Each Other Openly.

Hence Open Is A Part Of The Acronym

OSI Model

OSI Means Interconnecting Computer Systems In An Open Manner But With Certain Standards In Place.

It Is Concerned With The Way The Systems Exchange Information And Not With The Internal Functions Of The Particular System

OSI ModelsQUESTIONS?

Layers Of The OSI ModelSECTION 2

Layers Of The OSI Model

The Layers Of The Open System Interconnect Models

1. Physical

2. Data Link

3. Network

4. Transport

5. Session

6. Presentation

7. Application


It Is Important to note that Each of these different layers has its own set of functions

And only communicates with the layers directly above and below and with its opposite layer on other computers.

Layers Of The OSI ModelQUESTIONS WILL BE POINTED OUT IN LATER SECTIONS

The Purpose Of The Layered ModelSECTION 3

The Purpose Of The Layered Model

There Are 5 Main Reasons Why The OSI Model Is Used.

Change Design Learning Troubleshooting Standards

The Purpose Of The Layered Model | Change

A Concern In Technology Is Usually How One Affects The other.

When changes are made to one layer, the impact on the other layers is minimized.

However, If on the other hand, the model consists of a single, all-encompassing layer, any change affects the entire model.

The Purpose Of The Layered Model | Design

A Layered Model Defines Each Layer Separately.

The Thing Is, Long As The Interconnections Between Layers Remain Constant, Then Protocol Designers Can Specialize In One Area/Layer Without Worrying About How Any New Implementations Affect Other Layers.

The Purpose Of The Layered Model | Learning

The layered approach reduces complexityThough Many Persons are tech whiz it

doesn’t mean they do well with complex stuff.

Topics, activities, and actions are reduced into several smaller, interrelated groupings.

This makes learning and understanding the actions of each layer and the model generally much easier.

The Purpose Of The Layered Model | Troubleshooting

The protocols, actions, and data contained in each layer of the model relate only to the purpose of that layer.

This makes stuff easier because now, troubleshooting efforts to be pinpointed on the layer that carries out the suspected cause of the problem.

That Makes The Target Easy To Identify and The Kill Clean

The Purpose Of The Layered Model | Standards

Possibly the most important reason for using a layered model is that it establishes a prescribed guideline for interoperability(exchange) between the various vendors developing products that will perform different data communications tasks.

This Prevents Them From Doing Cunning Things Like Sneaking Into Your Business Or Watching Your Conversations.

The Purpose Of The Layered Model | Standards

Remember, though, that layered models- not excluding the OSI model- provide only a guideline and framework,

What Does This Mean?It Means It Does not provide a rigid standard

that manufacturers can use when creating their products.

The Purpose Of The Layered ModelQUESTIONS?

Seven Layers Of The OSI Model in DetailsSECTION 4


The Layers Of The Open System Interconnect Models

1. Physical

2. Data Link

3. Network

4. Transport

5. Session

6. Presentation

7. Application

Seven Layers Of The OSI Model in Details | Physical

First Of All, The Physical Layer Is The Lowest Layer (Or First Layer) Of The OSI Model.

It Contains The Physical Networking Medium, I.E. Cabling, Connectors, And Repeaters.


The Physical Layer Defines The Physical Network Structures

It Also Defines The Mechanical And Electrical Specifications For Using The Transmission Medium

And Also Bit Transmission Encoding And Timing Rules


Though The Main Focus Is Physical Attributes, The Physical Layer Does Not Include A Description Of The Medium And Does Not Provide Any Sort Of Error Correction.

However, Implementations Of Physical Protocols Are Transmission-media-specific


Some Of The Common Medium AreNetwork Interface Boards Hubs, And RepeatersTransmission Media Connectors (Provide The

Mechanical Interface To Interconnect Devices To The Transmission Media I.E. Cables, BNC Connectors, Etc)

Modems And Codec's, Which Perform Digital Analogue Conversions.

Seven Layers Of The OSI Model in Details | Data Link

The Second Layer Of The OSI Model Is The Data Link Layer.

This Controls Communications Between The Network Layer And The Physical Layer.

Its Primary Function Is To Divide Data It Receives From The Network Layer Into Distinct Frames That Can Be Transmitted By The Physical Layer.

Seven Layers Of The OSI Model in Details | Data Link

The Basic Purposes Of The Data Link Layer Protocol Implementations Includes:Organise The Physical Layer’s Bits Into

Logical Groups Of Information (aka Frames)Detect And Correct ErrorsControl Data FlowAnd Identify Computers On The Network

Seven Layers Of The OSI Model in Details | Network

The Primary Function Of Layer Three (Network) Is Moving Data To Specific Network Locations.

By Translating Logical Addresses Into The Appropriate Physical Address

Then Decides On The Best Route For The Data To Take From Sender To Receiver.

Seven Layers Of The OSI Model in Details | Network

Though This May Seem Similar To What The Data Link Layer Accomplishes Through Physical Decide Addressing.

The Data Link Layer Addressing Only Operates On A Single Network.

The Network Layer However, Addressing Only Operates On Multiple Independent Networks (Internetworks).

Seven Layers Of The OSI Model in Details | Transport

This Layer Provides Enhancements To The Services Of The Network Layer.

Its Main Tasks Is To Ensure That Data Sent Form One Computer Arrives Reliably

Meaning In The Correct Sequence And Without Errors At The Receiving Computer.


To Do This, The Transport Layer Builds On The Error Control Mechanism Provided By The Lower Layer.

This Layer Is The Last Chance For Error Recovery.


The Transport Layer Is Also Responsible For Flow Control.

Here Is Where The Rate Of Transmission Is Determined.

Based On How Fast The Receiving Computer Can Accept The Data Packets Being Sent To It.


Data On The Sending Computer Is Broken Down Into Packets That Are The Maximum Size That The Type Of Network Can Handle.

Seven Layers Of The OSI Model in Details | Session

This Layer Is Responsible For Establishing And Maintaining Communication Between Two Nodes On The Network.

The Term Session Refers To A Connection For Data Exchange Between Two Parties;


It Is Most Often Used In The Context Of Terminal And Mainframe Communications, In Which The Terminal Is A Device With Little (If Any) Of Its Own Processing Or Disk Capacity.

That Means It Depends On A Host To Supply It With Applications And Data Processing Services.


Often, This Layer Also Helps The Upper Layers Identify And Connect To The Services That Are Available On The Network.

If A Communication Session Is Broken, The Session Layer Is Tho One That Determines Where To Restart The Transmission Once The Session Has Been Reconnected


Not Only Does This Layer Monitor The Sessions But This Layer Is Also Responsible For Determining The Terms Of The Communication Session

It Will Determine Which Computer Or Node Can Communicate First And For How Long

This Makes It Known As The Traffic Cop

Seven Layers Of The OSI Model in Details | Presentation

The Presentation Layer Serves As A Translator Between The Application And The Network.

At The Presentation Layer, Data Become Formatted In A Schema That The Network Can Understand

This Format Varies With The Type Of Network Used.

Seven Layers Of The OSI Model in Details | Presentation

The Presentation Layer Manages Data Encryption And Decryption, Such As The Scrambling Of System Passwords.

Seven Layers Of The OSI Model in Details | Application

The Top Or Seventh Layer Of The OSI Model Is The Application Layer.

The Application Layer Provides Interfaces To The Software That Enable Programs To Use Network Services.


The Term “Application Layer” Does Not Refer To A Particular Software Application, Such As Microsoft Word, Running On The Network.

Instead, Some Of The Services Provided By The Application Layer Include File Transfer, File Management, And Message Handling For Electronic Mail.


Examples Of Common Functions Include:Protocols For Providing Remote File Services,

I.E. Open, Close, Read, Write, And Shared Access To Files

File Transfer Services And Remote Database Access

Message Handling Services For Electronic Mail Applications


Examples Of Common Functions Include:Global Directory Services To Locate

Resources On A NetworkA Uniform Way Of Handling A Variety Of

System Monitors And DevicesRemote Job Execution

Conclusion