1.introduction to data communication and networks

7/31/2019 1.Introduction to Data Communication and Networks

1/39

Computer Networks -Introduction

Presentation by

A.Jawahar

SSN College of Engineering


2/39

Objective

At the end of this section students will be

able to understand The concept of Data Communication

Networking Protocols and Standards


3/39

Data Communication

Exchange of data between two devices via

some form of transmission medium Effectiveness of data communication

depends on Delivery Accuracy

Timeliness Jitter


4/39

Components of Data Communication Message

Sender Receiver

Transmission medium Protocol


5/39

Components of Data Communication


6/39

Data Representation

Text

Numbers

Images

Audio Video


7/39

Data flow Simplex

Half Duplex Full Duplex


8/39

Data flow - Simplex


9/39

Data flow Half duplex


10/39

Data flow Full Duplex


11/39

Networks A network is a set of devices (called nodes)

connected by communication links. A node maybe a computer, printer or any other devicecapable of sending and/or receiving datagenerated by other nodes in the network.

Distributed Processing

Network Criteria

Physical Structures

Categories of Networks


12/39

Distributed Processing Most networks use distributed processing,

in which a task is divided among multiplecomputers.


13/39

Network Criteria Performance

Reliability Security


14/39

Physical Structures

Type of connection Point to Point Multipoint


15/39

Point to Point


16/39

Multipoint


17/39

Physical Topology


18/39

Physical Topology - Mesh


19/39

Physical Topology - Star


20/39

Physical Topology - Bus


21/39

Physical Topology - Ring


22/39

Network Models OSI model seven layered

Internet model five layered


23/39

Categories of Networks


24/39

LAN


25/39

LAN


26/39

MAN


27/39

WAN


28/39

Protocols and StandardsProtocols

Standards

Standards Organizations

Internet Standards


29/39

Protocols Syntax

Semantics Timing


30/39

Standards De facto by fact

De jure by law


31/39

Standard Organizations ISO

ITU-T CCITT

ANSI EIA

Forums Regulatory Agencies - FCC


32/39

Internet Standards An internet standard is a thoroughly

tested specification that is useful to andadhered to by those who work with theinternet.

Internet draft

Request for comment (RFC)


33/39

Summary Data communications are the transfer of

data from one device to another via someform of transmission medium.

Accurate and timely transmission.

Components message, sender, receiver,medium, protocol

Data forms image, text, audio, video

Data flow simplex, half duplex, fullduplex


34/39

Summary A network is a set of communication

devices connected by media links.

Topology mesh, star, bus, ring

Network categories LAN, MAN, WAN

An internet is a network of networks. An internet is a collection of many

separate networks

There are logical, regional, national andinternational Internet Service Providers.


35/39

Summary Protocol set of rules that govern data

communication

Standards ensure that products fromdifferent manufacturers can work together


36/39

Review Questions In a _______ connection, more than two devices can

share a single link.

A) Point-to-point B) Primary C) Multipoint D)

Secondary Communication between a computer and a keyboardinvolves ______________ transmission.

A) Full-duplex B) Half-duplex C) Simplex D)

Automatic The information to be communicated in a data

communications system is the _______.

A) Medium B) Protocol C) Transmission D) Message

Frequency of failure and network recovery time after afailure are measures of the _______ of a network.

A) Performance B) Security C) Reliability D) Feasibility


37/39

Review Questions In a network with 25 computers, which topology would

require the most extensive cabling?

A) Star B) Mesh C) Bus D) Ring Which topology requires a central controller or hub? A)

Star B) Mesh C) Bus D) Ring

The _______ is the physical path over which a messagetravels.

A) Protocol B) Medium C) Signal D) All the above

Which organization has authority over interstate andinternational commerce in the communications field?A) ITU-T B) IEEE C) ISO D) FCC


38/39

Review Questions In _______ transmission, the channel capacity is shared

by both communicating devices at all times.A) Full-duplex B) Simplex C) Half-duplex D) Half-simplex

An unauthorized user is a network _______ issue.A) Performance B) Reliability C) Security D) All theabove

Which topology requires a multipoint connection?A) Mesh B) Star C) Ring D) Bus

A television broadcast is an example of _______

transmission.A) Half-duplex B) Full-duplex C) Simplex D)Automatic


39/39

Review Questions A _______ connection provides a dedicated link between

two devices.

A) Multipoint B) Point-to-point C) Primary D)Secondary

A cable break in a _______ topology stops all

transmission.A) Mesh B) Star C) Primary D) Bus

1.introduction to data communication and networks

Documents