OSI Reference Model

5/24/2018 OSI Reference Model

1/48

OSI Reference Model

V1.0

Data Customer Service Dept.


2/48

For Internal

Use Only

Internal Use Only

Course Objectives

Grasp the basic knowledge of network

Understand network evolution history and classification ofnetwork

Know standardization organizations in data communication

field Grasp OSI model and each layers function

Grasp the function of different kind of network devices and itsposition


3/48

For Internal

Use Only

Internal Use Only

Course Outline

Chapter I Network Overview

Chapter II OSI Reference Model


4/48

For Internal

Use Only

Internal Use Only

Course Contents


Section 1 Definition and Evolution History of Network

Section 2 Classification of Network

Section 3 Network Topology

Section 4 International Standardization Organizations


5/48

Internal Use Only

Definition of Network

Computer network refers to interconnect the separately distributedcomputers and external communication lines to form a system for

easy info exchanging and resource sharing among multiple pieces of

computers.

IP HotelMobile

Server SOHO


6/48

Internal Use Only

Network Evolution History

Phase 270s 80s

Phase 4 80s till now

Phase 1 50s 60s


7/48

For Internal

Use Only

Internal Use Only

Course Contents







8/48

Internal Use Only

Classification of Network

Local Area Network (LAN)

Metro Area Network (MAN)

Wide Area Network (WAN)


9/48

Internal Use Only

LAN

LAN usually covers an area of several kilometers and integrated

several independent data devices to enable users to share

network resources.

Features: short distance, low latency, high data-transmitting rate

and reliable transmission.

The infrastructures of LAN include servers, clients, network

equipments and communication media.


10/48

Internal Use Only

MAN

MAN usually covers an area of several kilometers to

hundreds of kilometers

Data transmission rate ranged from several Kbit/s to several

Gbit/s

Optical fiber is the best transmission media of MAN


11/48

Internal Use Only

WAN

WAN is mainly used to connect LANs, and provide data

communication within wide areas.

WAN covers an area of hundreds to thousands of

kilometers.

Classification of WAN:

ISDN

DDN

X.25 packet switching networkFrame Relay

ATM


12/48

For Internal

Use Only

Internal Use Only

Course Contents







13/48

Internal Use Only

Network Topology

Star Topology

Tree Topology

Distributed Topology

Ring Topology

Bus Topology

Hybrid Topology


14/48

For Internal

Use Only

Internal Use Only

Course Contents







15/48

Internal Use Only

Standardization Organizations

International Organization for Standardization (ISO)

International Telecommunications Union (ITU)

Institute of Electrical and Electronics Engineering (IEEE)

American National Standard Institute (ANSI)

Electronic Industries Association/ Telecommunication

Industry Association (EIA / TIA)

Internet Engineering Task Force (IETF)Internet Architecture Board (IAB)

Internet Assigned Numbers Authority (IANA)


16/48

For Internal

Use Only

Internal Use Only

Course Contents


Section 1 OSI Model Overview

Section 2 Physical Layer

Section 3 Data-link Layer

Section 4 Network Layer

Section 5 Transport Layer

Section 5 Session/Presentation/Application Layer


17/48

Internal Use Only

OSI Reference Model Overview

Data Transmission

between Networks

Transport Layer

Data-link Layer

Network Layer

Physical Layer

Data Transmission

between HostsSession Layer

Presentation Layer

Application Layer

OSI RMOpen System Interconnection Reference Model


18/48

Internal Use Only

Functions of Each Layer

1

2

3

4

5

6

7Provide communication between

application programs

Process data format and encryption

Establish, maintain and manage sessions

Establish end-to-end connection

Addressing and routing

Provide media access and linkmanagement

Bit stream transmission

Transport Layer

Data-link Layer

Physical Layer

Session Layer

Presentation Layer

Application Layer

Network Layer


19/48

Internal Use Only

Relationship between Each Layer of OSI Model

Only peer layers with same protocol are able to communicate.

Transport Layer

Data-link Layer

Network Layer

Physical Layer

Session Layer

Presentation Layer

Application LayerAPDU

Bits

Frame

Packet

Segment

SPDU

PPDU

Transport Layer

Data-link Layer

Network Layer

Physical Layer

Session Layer

Presentation Layer

Application Layer


20/48

Internal Use Only

Upper Layer Data

Upper Layer DataTCP Header

IP Header

LLC Header

0101110101001000010

MAC Header

Segment

Packet

Bits

Frame

PDU

FCS

FCS

Data Encapsulation

Transport

Layer

Data-link Layer

Physical

Layer

Network

Layer

Presentation LayerApplication Layer

Session Layer

Upper Layer Data

Upper Layer Data

Upper Layer Data


21/48

Internal Use Only

Upper Layer Data

LLC Hdr + IP + TCP + Upper Layer Data

IP + TCP + Upper Layer Data

TCP+ Upper Layer Data

Upper Layer Data

0101110101001000010

Transport Layer

Data-link Layer

PhysicalLayer

NetworkLayer

Presentation Layer

Application Layer

Session Layer

Data De-encapsulation


22/48

For Internal

Use Only

Internal Use Only

Study Contents









23/48

Internal Use Only

Physical Layer

EIA/TIA-232V.35Physical Layer

Moves bits between devices

Specified voltage, rate and pin-out cables

Physical Layer is the first and bottom layer of OSIReference Model.

Physical Layer mainly provides bit stream transmission.


24/48

Internal Use Only

Physical Layer also defines:

Media Type

Connector Type

Signal Type

Function of Physical Layer

Ethernet

8

02.3

V.3

5

Physical

Layer

EIA/TIA-232


25/48

Internal Use Only

HUB

Host

Host

10Base2Ethernet thin-wire

10Base5Ethernet thick-wire

10BaseTTP

Ethernet/802.3


26/48

Internal Use Only

HUB works on Physical Layer

The work stations connected via HUB are physically Star

Topology but Bus Topology logically.

All devices are in one Collision Domain

The more terminals, the more collisions

All devices share the bandwidth

Collision Domainan assembling of all the workstations on the

same cable or of all the nodes on the same physical segment or a

group of nodes contending the same bandwidth.

HUB


27/48

For Internal

Use Only

Internal Use Only

Study Contents









28/48

Internal Use Only

802.3 / 802.2

HDLC

EIA/TIA-232

V.35

Data-link Layer

Data-link

Layer

Combines packets into bytes and bytes to

frames

Provides access to media using MAC address

Performs error detection not correction

Physical

Layer


Specified voltage, rate and pin-out cables

Data-link Layer is the second layer of OSI Reference Model

Mainly responsible to precisely transmit the data packet to Network

Layer of destination host.


29/48

Internal Use Only

Data-link Layer defines:

Physical source and destination addresses

Associate SAP (service access point) to upper layer protocols

Define network topology

Control of frame order

Flow Control

data-

EIA/TIA-232

v.35

802.2

802.3

Function of Data-link Layer

Data-link

Physical

EIA/TIA-232

v.35

FR802.2

802.3


30/48

Internal Use Only

DataSource

addressFCSLength

Destination

address

Variable Length266 4

00.d0.d0 xx.xx.xx

Distributed bymanufacturer

The manufacturercode assigned by

IEEE

Preamble

Ethernet II uses

Type in this

field.

MAC address

8# Bytes

MAC Address


31/48

Internal Use Only

Layer 2 Switch and Bridge work on Data-link Layer

Each network segment connected to each port is an

individual Collision Domain

All network segments are in one Broadcast Domain

Broadcast Domainassembly of nodes that receive same

broadcast message, able to be classified into one logical network

segment with other broadcast nodes.

Switch/Bridge


32/48

Internal Use Only

HUB Bridge Switch Router

Number ofCollision

Domain: 1 4 4 4

Number of

Broadcast

Domain:1 1 1 4

Collision Domain and Broadcast Domain


33/48

For Internal

Use Only

Internal Use Only

Study Contents









34/48

Internal Use Only

Network Layer

EIA/TIA-232

V.35

IP

IPX

Network

Layer

Provides logic addressing which

routers use for path determination

Data-link

Layer

Combines packets into bytes and bytes to

frames



Physical

Layer


Specifies voltage, rate and pin-out cables

802.3 / 802.2

HDLC


35/48

Internal Use Only

Defines Logical

Address

Addressing andRouting

Network

LayerIP, IPX

Data-link

Layer

Physical

LayerEIA/TIA-232

v.35

HDLC

802.2

802.3

Functions of Network Layer

FR


36/48

Internal Use Only

Network Layer address is globally unique, constituted

by two parts: Network address and Host address.

IP

address

IPXaddress

Network address Host address

10. 8.2.48

Network addressHost address

1aceb0b1. 0000.0c00.6e25

Logical Address(1)


37/48

Internal Use Only

11111111 11111111 00000000 00000000

10101100 00010000 01111010 11001100

Binary Mask

Binary Address

172.16.122.204 255.255.0.0

172 16 122 204

255

Address Mask

255 0 0

Network Host

Logical Address(2)


38/48

Internal Use Only

Functions:Logical routing

Select best routing path

Broadcast control

Multicast Control

Flow Control

Connected to WAN

Router


39/48

For Internal

Use Only

Internal Use Only

Course Contents









40/48

Internal Use Only

TCP

UDP

SPX

802.3 / 802.2

HDLC

EIA/TIA-232

V.35

IP

IPX

Transport Layer

Transport

Layer

Provides reliable or unreliable delivery

Performs error correction before

retransmit

Network

Layer

Provides logical addressing,

which routers use for path determination

Data-link

Layer

Combines packets into bytes and bytes into frames



Physical

Layer


Specifies voltage, rate, and pin-out cables


41/48

Internal Use Only

Functions:

Segment Upper Layer Data

Establish end-to-end connection between application programs

Flow control

Connection-oriented and connectionless Communication

Network

Layer IPXIP

Transport

LayerSPXTCP UDP

Function of Transport Layer


42/48

Internal Use Only

Synchronizing

Acknowledgement, Synchronizing

Acknowledgement

Data Transmission

Sender Receiver

Connection Established

Connection-oriented Session


43/48

For Internal

Use Only

Internal Use Only

Course Contents









44/48

Internal Use Only

Session Layer

Transport

Layer


Performs error correction before retransmit

Network

Layer



Data-link

Layer

Combines packets into bytes and bytes into frames

Provides access to media using MAC address Performs error detection not correction

Physical

Layer



Keeps different applications data separateSession

Layer


45/48

Internal Use Only

Presentation Layer

Presents data Handles processing such as encryption

PresentationLayer

TransportLayer


Performs error correction before retransmit

Network

Layer



Data-linkLayer

Combines packets into bytes and bytes into frames Provides access to media using MAC address


Physical

Layer




Layer


46/48

Internal Use Only

Provides a user interfaceApplication

Layer

Presents data

Handles processing such as encryption

Presentation

Layer

Transport

Layer

Provides reliable or unreliable delivery Performs error correction before retransmit

Network

Layer



Data-link

Layer

Combines packets into bytes and bytes into frames Provides access to media using MAC address


Physical

Layer


Specifies voltage, wire speed, and pin-out cables


Layer

Application Layers


47/48

Internal Use Only

Summary

Definition of Network

Network Evolution History

Classification of Networks

Network Topology Standardization Organizations in Data

Communication Field

OSI Model and Functions of Each Layer

Common Network Devices


48/48

Date post:	14-Oct-2015
Category:	Documents
Upload:	matthew-carter
View:	31 times
Download:	0 times

OSI Reference Model

Documents