Chapter 01_Living in a Network-Centric World

7/27/2019 Chapter 01_Living in a Network-Centric World

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Chapter 1- Living in a Network Centric World

CCNA Exploration 4.0



Objectives

• Describe how networks impact our daily lives.

• Describe the role of data networking in the human network.

• Identify the key components of any data network.

• Identify the opportunities and challenges posed by

converged networks.• Describe the characteristics of network architectures: fault-

tolerance, scalability, quality of service and security.

• Install and use IRC clients and a Wiki server.



Communication in a

Network-Centric World



How Networks Impact Daily Life

• Communication is almost as important to us as our reliance on air,

water, food, and shelter.• The communication method changes and evolves constantly.

• Early data network: limited to exchanging character-based informationbetween connected computer systems.

• Current networks have evolved to carry voice, video streams, text, and

graphics between many different types of devices.




The way we live




Some popular communication media:

• Instant messaging: Real time communicationbetween 2 or more people based on typed text

• Weblogs (Blogs): Web pages created by an

individual, easy to update and edit• Wikis: Web pages created by anyone, likes weblogs

but more public

• Podcasting: Website that contains audio filesavailable for downloading

• Collaboration Tools: give people the opportunity to

work together on shared documents.




The way we learn

• Communication, collaboration, and engagement are

fundamental building blocks of education. The learning

materials include interactive activities, assessments, and

feedback.

• Traditional learning methods: student can obtain

information only from the textbook and the instructor.

• E-learning courseware: contain voice, data, and video; any

time, anywhere; online discussion. Combine instructor-led

classes with online courseware.

• Access to high quality instruction.

• Removed geographic barriers




• The Cisco Networking Academy Program is an example of

a global online learning experience.• Online courseware and delivery offer many benefits:

– Current and accurate training materials.

– Availability of training to a wide audience.

– Consistent quality of instruction. – Cost reduction.




The way we work

• Many different types of information services: e-mail, video,messaging, and telephony.

• Intranets for private, extranets for suppliers, vendors, and

customers.




The way we play

• Supported by services delivered by the data network



Communication –

An essential Part of Out Lives



Communication

• Basic characteristics of communication

– Rules or agreements are 1st established

– Important information may need to be repeated

– Various modes of communication may impact the

effectiveness of getting the message across.



Quality of Communications

• Communication is successful when the meaning of the message

understood by the recipient matches the meaning intended by thesender.

• Many factors can prevent the message from reaching the recipient or

distort its intended meaning: external and internal.

External Factors

• The quality of the pathway between the sender and the recipient

• The number of times the message has to change form

• The number of times the message has to be redirected or readdressed

• The number of other messages being transmitted simultaneously on

the communication network

• The amount of time allotted for successful communication

Internal Factors

• The size of the message

• The complexity of the message

• The importance of the message



Quality of Communications



The Network as a Platform



Data Networking Role

• Data or information networks: used for delivering of the

millions of messages; vary in size and capabilities, but have

four basic elements in common: Rules, The messages,

Medium, Devices



Data Networking Components

• Devices: these are used to communicate with one another • Medium: this is how the devices are connected together

• Messages: information that travels over the medium

• Rules: governs how messages flow across network



The Elements of a Network

• Common devices:

– Switch – Firewall

– Router

– Wireless Router

– Cloud

– Serial Link




Network Connections




• Human beings often seek to send and receive a variety of

message using computer applications; these applicationsrequire services be provided by the network.

• Protocols are the rules that the networked devices use to

communicate with each other.



Sending an Instant Message: Example



Converged Networks

• Multiple networks:

each service has itsown individual

version of four basic

network elements

• Converged networks:

can carry voice, video

& data over the same

network



Converged Networks

• Intelligent Information Networks: offer so much more

than basic connectivity and access to applications.

• Planning for the Future



The Architecture of the Internet



Network Architecture Characteristics

•

Network architecture: refers to both the technologies that support the infrastructure and the programmed

services and protocols that move the messages

across that infrastructure. Four basic characteristics that

the underlying architectures need to address in order to

meet user expectations: fault tolerance, scalability,quality of service, and security.



Four Characteristics



Fault Tolerant Network Architecture

• DoD (the United States Department of Defense): research a

communications medium that could withstand the destruction of numerous sites and transmission facilities without disruption of

service fault tolerance.

• Circuit switched Connection-oriented Network: telephone systems



Fault Tolerant Network Architecture

• Packet Switched Connectionless Networks



Scalable Network Architecture

• The Internet: is able to expand, has a hierarchical layered

structure for addressing, for naming and for connectivityservices. Maintain peering relationships with other at the

same level.



Quality of service



Quality of service

• Quality of Service (QoS): to prioritize which types of data

packets must be delivered at the expense of other types of packets that can be delayed or dropped. Two steps:

Classification and Assigning priorities



Quality of service

• Examples of priority decisions: time-sensitive; non time-

sensitive; high importance; undesirable communication.



Network Security

• The network infrastructure, services, and the data are

crucial personal and business assets. Compromising theintegrity of these assets could have serious business andfinancial repercussions.

• Consequences of a network security breach could include:

–

Network outage that prevents communications andtransactions occurring, with consequent loss of business

– Misdirection and loss of personal or business funds

– Company intellectual property (research ideas, patents

or designs) that is stolen and used by a competitor – Customer contract details that become known to

competitors or made public, resulting in a loss of marketconfidence in the business



Network Security



Network Security

• Ensure confidentiality:

– User authentication

– Data encryption

• Maintain communication integrity:

–Digital signatures

• Ensure availability:

– Firewalls

– Redundant network

architecture – Hardware without a

single point of failure



Trends in Networking



Trends in Networking

– Increasingnumber of mobileusers

–

Proliferation of network capabledevices

– Expanding rangeof services

• There are three major trends that are contributing to the

future shape of complex information networks:



Networking Career Opportunities

• Information Technology and networking careers are growing and

evolving as fast as the underlying technologies and services. Asnetworks increase in sophistication, the demand for people with

networking skills will continue to grow.

• Traditional IT positions like programmers, software engineers, data

base administrators and network technicians are now joined by new

titles, such as network architect, e-Commerce site designer,information security officer, and home integration specialist.

Opportunities for forward thinking entrepreneurs are unlimited.

• Even non-IT jobs, like manufacturing management or medical

equipment design, now require a significant amount of knowledge

about network operation in order to be successful.• Chief Technology Officers in many large organizations list the lack of

qualified personnel as the primary factor delaying the implementation

of innovative new services.

S



Summary

Documents

Chapter 01_Living in a Network-Centric World