Netwoking

SPM1012SPM1012TELECOMMUNICATION & NETWORKINGTELECOMMUNICATION & NETWORKING

Session 2007 /2008 (II)Session 2007 /2008 (II)

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORK

“ although computers can be operated in stand-alone mode, but to improve the performances of task / output, it must be networked or communicate with others “

Eg : Computer network at PSZ, Interactive lab, etc..

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKToday discussion will be on :

Computer networking ; just an introduction The importance of networking Data communication. Introduction to networking

• devices & equipments• Software

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKWhat you can conclude from this picture ??

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORK????

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORK

home

cable headend

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKWhat is computer networking?

Computer networking is connecting a computer with other computers or devices to enable them to communicate with each other.

The collection & distribution of the electronics data (bits) representation of information from remote location.

This type of communication either via wired or unwired medium

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKWhat is computer networking?

The information can be appear in variety formats (eg : multimedia elements).

It can be : • Computer devices or equipments• Software

• Transmission media to send / control the data / signals,

• Communication devices to transmit / send data from sources to destinations

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKActivities…

List out devices that can be connected by computer network

1. ??2. ??3. ??4. …

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKExample?

Using RJ-45 UTP cable to make a connection into Internet @ Laptop Zone, PSZ

Data Transmission ModeData Transmission ModeTypes of Data Transmission Modes:

Parallel transmission Separate line for each bit

Serial transmission All the bits transmitted on a single line

What you can conclude from this two types of transmission mode?

Data Transmission ModeData Transmission ModeParallel transmission & Serial transmission

Communication SignalCommunication SignalTypes of Signal In Data Transmission :

Analogue signal Eg: voice wave

Digital signal Binary codes (1 / 0)

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKTypes of basic computer networking based on

geographic coverage :

LAN – Local Area Network WAN - Wide Area Network

Others? MAN - Metropolitan Area Network CAN – Campus Area Network

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKMind Activity

What the different between NETWORK & COVERAGE?

INTRODUCTION INTO NETWORKINTRODUCTION INTO NETWORKNetworking components can be categorize into :

Terminals, Workstations, Computers & other related devices (eg : PC, laptop, server, printer)

Transmission Media (for transmitting data and control signals) (eg : RJ-45 cable, Wifi UTM)

Network ComponentsNetwork Components

Network electronics (intermediate devices for routing data from source to destination) (eg : Hub)

Software to control data transmission (eg : Windows NT 4.0)

Network Architecture Standards (Standards to enable devices made by different companies to work/communicate with each other.

Terminal & WorkstationsTerminal & Workstations

Normally refers to data sources and destinations. Eg :

• Personal computers• Terminals• Workstations• Computers• Automatic teller machines

Transmission MediaTransmission Media

The physical media used to transmit data in a networked environment.

To Transmit signal / electrical pulse through a

medium.

2 types : bounded / guided or unbounded / unguided

(wired) (unwired)

Transmission MediaTransmission Media

Bounded Media Unbounded Media (air or a vacuum)

- Twisted pair wire - AM & FM (Radio frequency)

- Co-axial cable - TV broadcasting- Fiber optic cables - Satellite communication

- Microwave oven & radio

- Infrared signals

Network Electronic DevicesNetwork Electronic Devices

Devices that controls data transmission from sources to destinations,

It also act as interface between different transmission media or communication protocol

Network Electronic DevicesNetwork Electronic Devices Network Electronic Devices. Example ;

- Bridges - Concentrators- Routers - Front End Processors - Private Branch - Switches Exchange (PBX) - Hubs- Multiplexers - Gateways

SoftwareSoftware At the nodes : involve techniques and protocols

which determine the procedure how to transmitted, terminated, transfer and display the data and also controlling the data.

Software for the network devices is to controlling or make sure the data reach right target / destination

Eg : Key in e-mail address in Outlook in the way to send the mail.

Network Architecture StandardsNetwork Architecture Standards

Architecture: blueprint of standards for a network consisting / include of items such as choice of media (cable), media interfaces (NIC), encoding methods (software / packet), transmission protocols, routing protocols, etc.

Network Architecture StandardsNetwork Architecture Standards

Transmission Control Protocol is the transport protocol that manages the individual conversations between web servers and web clients. TCP divides the HTTP messages into smaller pieces, called segments, to be sent to the destination client. It is also responsible for controlling the size and rate at which messages are exchanged between the server and the client

Network Architecture StandardsNetwork Architecture Standards

Needed to ensure interoperability between various devices and equipment made by different vendors.

Using of NetworkUsing of Network

Resource sharing (information/data/devices) borderless

No time constrain –accessible @ anytime @ anywhere

High reliability

Using of NetworkUsing of Network

Scalability• Computer networks provide an effective

mechanism to scale up and provide services to more users at more locations where needed and when needed.

Manageability• Networks allow remote resources to be managed

effectively (eg., remote control of telescopes or other resources).

Using of NetworkUsing of Network

Cost - Effectiveness• Networks allow effective implementation of

complex distributed systems that must work together (cooperate). Eg : combination of mainframes, workstations, PC’s, networked storage & printers.

• Provide access to needed resources from anywhere at anytime.

• Support collaborative group work independent of location

Using of Network (Individual)Using of Network (Individual)

Database access• Bank/ other institution• Online shopping.• Online News paper• On line job/Telecommuting (e-services)• Digital libraries.

Using of Network (Individual)Using of Network (Individual)

Online communication• E-mail• Video conferencing.• New group / online forum / chat• E-learning / virtual learning.

Using of Network (Individual)Using of Network (Individual)

Interactive entertainment.• multimedia games.• video on demand (VOD):

order movies or television shows of choice at anytime from anywhere (IpTV)

interactive movies and shows

Network ; The importantNetwork ; The important

The importance of computer networks:1. …2. …3. …4. …

Flow of Network CommunicationFlow of Network Communication

Communications network can provide many types ofservice

Simplex One way all the time Duplex Two way

• Half Duplex Two ways in Two times• Full Duplex Two ways in One times

Multiplexing More than one device transmitted the data through single line at the same time

Flow of Network CommunicationFlow of Network Communication

Simplex :

One way communications One device transmits data, and the other device

receives data. Eg : ????

Flow of Network CommunicationFlow of Network Communication

Half Duplex :

One way communication in a time Queue delaying to transmit the data Eg : ????

Flow of Network CommunicationFlow of Network Communication

Full Duplex :

Two Way communication in one time Eg : ????

Flow of Network CommunicationFlow of Network Communication

Multiplex :

Flow of Network CommunicationFlow of Network Communication

1. Duplex links are classified as either full duplex or half duplex (also known as two way alternate), depending upon whether both local and remote nodes may simultaneously transmit.

2. Whether one must wait for the other to finish before starting transmission.

(A telephone line is capable of full duplex transmission, although most human users choose to adopt a half duplex procedure to listen to what the remote person has to say)

Flow of Network Flow of Network CommunicationCommunication

3. (A telephone line is capable of full duplex transmission, although most human users choose to adopt a half duplex procedure to listen to what the remote person has to say)

Networks Devices : Local Area NetworkNetworks Devices : Local Area Network

NIC (Network Interface Card) : Media (Network cable) Hub/Repeaters Server Workstations

Networks Devices : Local Area NetworkNetworks Devices : Local Area Network

Software :

NOS (Network operating Software) – Server

Eg : Windows NT 4.0, Windows Advance Server

NCS (Network Client Software) – Workstation

Eg : Windows XP, Windows ME

Networks PerformanceNetworks Performance

Networks Performance depends on its bandwidth

Bandwidth : Maximum speed at which a particular communication can transfer or carry the data.

For example, an analog phone line accommodates a bandwidth of 3,000 hertz (Hz), the difference between the lowest (300 Hz) and highest (3,300 Hz) frequencies it can carry.

In digital communications, bandwidth is expressed in bits per second (bps).

Networks PerformanceNetworks PerformanceActivities

1 bit = 1 / 0 ; 8 bits = 1 byte

Networks PerformanceNetworks Performance

Bandwidth. Example :

Dial-Up Bandwidth 56Kbps (maximum data transfer rate per second)

Broadband 1Mbps (maximum data transfer rate per second)

Dial-Up vs BroadbandDial-Up vs Broadband

Dial-up via modem• up to 56Kbps direct access to router (often less)• Can’t surf and phone at same time: can’t be

“always on”

ADSL: asymmetric digital subscriber line• up to 1 Mbps upstream (today typically < 256 kbps)• up to 8 Mbps downstream (today typically < 1

Mbps)• Bandwidth :

50 kHz - 1 MHz for downstream 4 kHz - 50 kHz for upstream 0 kHz - 4 kHz for ordinary telephone

Networks PerformanceNetworks Performance

Latency :

Amount of time to transmit a unit of data

Latency is sometimes referred to as propagation delay.

Cooper (dawai tembaga) = 3 * 10^8 m/sec

Networks PerformanceNetworks Performance

Packet Loss :

Occur when packets fail to reach correct destination.

Due to network traffic

Eg : ?????

Networks PerformanceNetworks PerformancePacket Loss :packets queue in router buffers packet arrival rate to link exceeds output link

capacity packets queue, wait for turn

A

B

packet being transmitted (delay)

packets queueing (delay)free (available) buffers: arriving packets dropped (loss) if no free buffers