Module 4 - Network Models

8/9/2019 Module 4 - Network Models

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Module 4

NETWORKING MODELS

IT Infrastructures & Network Applications (ITINFRA)

Quick Kit

Developed By:

Mr. Peter Abraham T. Solquillo

Mr. Gary R. SorianoFaculty - Computer Applications Program


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Network Models

OSI Model

Open Systems Interconnect / Interconnectivity

Model by ISO (International Standards

Organization)

TCP/IP Model

Transmission Control Protocol / Internet

Protocol

Model by the US Department of Defense (DoD)


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Visual Representation of Layers

Network

Post Office

What is flowing?

Sent Items Different Forms?

Letters, packages, parcels, money orders

Rules

Rules for packaging & attaching postage

Where?

P.O. boxes, offices, trucks, planes,

delivery people


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Why Layer Data?

It was developed to accommodate changes

in technology.

Each layer of a specific network model may

be responsible for a different function ofthe network.

Each layer will pass information up and

down to the next subsequent layer as data is

processed.


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Protocols

A set of rules or an agreement that

determines the format and transmission of

data in a network.

In data communications, data is beingpassed through several phases. During a

phase, data is changed so that the next

process will be able to read that data.


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The OSI Model

Application Layer

Presentation Layer

Session Layer

Transport Layer

Network Layer

Data Link Layer

Physical Layer

This model, released in

1984 was the descriptive

network model that the ISO

created.

It provided vendors with aset of standards that

ensured greater

compatibility and

interoperability among

various network technologies

produced by companies

around the world


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Benefits of the OSI Model

Reduces complexity

Standardizes interfaces

Facilitates modular engineering

Ensures interoperable technology

Accelerates evolution

Simplifies teaching and learning


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THE OSI LAYERS


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The PHYSICAL Layer

Translates communications requests from

the Data Link Layer into hardware-specific

operations to effect transmission or

reception of electronic signals.

Provides an electrical, mechanical, and

procedural interface to the

transmission medium.

Binary Transmission: wires, connectors,voltages, data rates


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Layer 1 Services

Modulation

Line Coding

Bit Synchronization

Bit Interleaving Channel Coding


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The DATA LINK Layer

It responds to service requests from the

Network Layer (Layer 3) and issues service

requests to the Physical Layer (Layer 1).

Provides the functional & procedural meansto transfer data between network entities

and might provide the means to detect and

possibly correct errors that may occur in the

Physical Layer Consists of two sub layers:

LLC (Logic Link Control)

MAC (Media Access Control)


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LLC (Logical Link Layer)

Multiplexing protocols transmitted over the MAC

layer (when transmitting) and demultiplexing

them (when receiving)

Providing flow and error control

MAC (Media Access Control)

Provides addressing and channel access control

mechanisms that make it possible for several

terminals or network nodes to communicate

within a multipoint network

acts as an interface between the

Logical Link Control (LLC) sublayer

and the network's physical layer


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Layer 2 Services & Protocols

SERVICES

Error Detection

Flow Control

PROTOCOLS

Ethernet

Fiber Distributed Data Interface (FDDI) Frame Relay

Point to Point Protocol (PPP)

Serial Line Internet Protocol (SLIP)


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The NETWORK Layer

Responds to service requests from the

Transport Layer and issues service requests

to the Data Link Layer.

Provides the functional & procedural meansof transferring variable length data

sequences from a source to a destination via

one or more networks while maintaining the

quality of service, & error control functions


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Layer 3 Protocols

PROTOCOLS

X.25 (Obsolete)

IPv4

IPv6 Internet Control Message Protocol (ICMP)

Internet Group Management Protocol (IGMP)


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The TRANSPORT Layer

Responsible for delivering data to the

appropriate application process on the host

computers.

Ensures properly sequenced and error freetransmission


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SERVICES

Flow Control

Byte Orientation

Ports

PROTOCOLS

Transmission Control User Datagram

Datagram Congestion Control

Stream Control Transmission


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The SESSION Layer


Presentation Layer (Layer 6) and issues

service requests to the Transport Layer

(Layer 4)

Provides the mechanism for opening, closing

and managing a session between end-user

application processes


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SERVICES

Authentication

Permissions

Session Restoration

PROTOCOLS

Network Basic I/O System (NetBIOS) Password Authentication Protocol (PAP)

Short Message Peer to Peer (SMPP)


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The PRESENTATION Layer


Application Layer and issues service

requests to the Session Layer

Responsible for the delivery and formattingof information to the application layer for

further processing or display.

Relieves the application layer of concern

regarding syntactical differences indata representation within the

end-user systems


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SERVICES

Encryption

Compression

PROTOCOLS

ASCII

EBCDIC


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The APPLICATION Layer

Interfaces directly to and performs common

application services for the application

processes.

Services provide semantic conversionbetween associated application processes.


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SERVICES

Virtual File & Terminal

Job Transfer

PROTOCOLS

Torrents

Telecommunication Network (Telnet) Post Office Protocol (POP, POP3)

File Transfer Protocol (FTP)

HTTP


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The TCP/IP Model

Application Layer

Transport Layer

Internet Layer

Link Layer

Also known as the Internet

Protocol Suite (IPS)

Set of communications

protocols used for the

Internet and other similarnetworks.

Each layer solves a set of

problems involving the

transmission of data, and

provides a well-defined

service to the upper layer

protocols based on using

services from some lower

layers.


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IPS Emergence

A better ARPANET

Introduced by Robert Kahn and Vinton Cerf

Devised a way to make layers simplified

and it should interface with other networks,regardless of architecture.


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IPS Timeline

1975

A test was performed between Stanford and

University College London.

1977

a three-network TCP/IP test was conducted

between the U.S., UK, and Norway

1982

US Department of Defense made TCP/IP thestandard for all military computer networking

January 1, 1983

Full control of TCP/IP over ARPANET


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THE IPS LAYERS


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The LINK Layer

A group of methods, protocols, and

specifications that is closest to the physical

network components used to connect hosts

or nodes in the network.

A suite of methods that operate only on the

link between adjacent network nodes.


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Link Layer Protocols

Address Resolution Protocol (ARP)

Reverse Address Resolution Protocol (RARP)

Neighbor Discovery Protocol (NDP)

Open Shortest Path First (OSPF)


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The INTERNET Layer

It is used to transport datagrams (packets)

from the originating host across network

boundaries.

Responsible in connecting multiple networkswith each other through gateways.


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Internet Layer Protocols

Internet Protocol (IPv4, IPv6)

Internet Control Message Protocol (ICMP)

Internet Group Management Protocol (IGMP)


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The TRANSPORT Layer

Responsible for encapsulating application

data blocks into datagrams (packets)

suitable for transfer to the network

infrastructure for transmission to the

destination host, or managing the reverse

transaction by abstracting network

datagrams and delivering them to an

application


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Link Layer Protocols

Transmission Control Protocol (TCP)

User Datagram Protocol (UDP)

Datagram Congestion Control Protocol

(DCCP) Resource reservation protocol (RSVP)

Explicit Congestion Notification (ECN)


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The APPLICATION Layer

Refers to networking protocols that are used

to support various services such as FTP,

Telnet, and BOOTP.


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Comparison of Models

Application

Presentation

Session

Transport

Network

Data Link

Physical

Application

Transport

Internet

Link

OSI Model IPS Model

Documents

Module 4 - Network Models