CCNA1-1 Chapter 1

Chapter 1Chapter 1

Living in aLiving in a

Network-Centric WorldNetwork-Centric World

CCNA1-2 Chapter 1

Communicating Communicating in ain a

Network-Centric Network-Centric World World

CCNA1-3 Chapter 1

Global AccessGlobal Access

• The globalization of the Internet has succeeded faster than The globalization of the Internet has succeeded faster than anyone could have imagined. anyone could have imagined.

• The manner in which social, commercial, political and The manner in which social, commercial, political and personal interactions occur is rapidly changing to keep up personal interactions occur is rapidly changing to keep up with the evolution of this global network.with the evolution of this global network.

CCNA1-4 Chapter 1

Networks – Behind the ScenesNetworks – Behind the Scenes

• Networks are more than just connecting cables.Networks are more than just connecting cables.• They are a complex and sophisticated combination of They are a complex and sophisticated combination of

protocols, softwareprotocols, softwareand hardware.and hardware.

• Security and PrivacySecurity and Privacy• 24 x 7 availability24 x 7 availability• Quality of ServiceQuality of Service• Video on DemandVideo on Demand• Voice over IPVoice over IP• Redundancy and backupRedundancy and backup• Mission critical applications and user expectationsMission critical applications and user expectations• WirelessWireless

CCNA1-5 Chapter 1

Networks – The Early DaysNetworks – The Early Days

• Early communication relied on face-to-face conversations.Early communication relied on face-to-face conversations.• The telephone was used for voice and the post office The telephone was used for voice and the post office

delivered most of the written communications. delivered most of the written communications. • Video communication was one-way using the television.Video communication was one-way using the television.

CCNA1-6 Chapter 1

Networks – The Early DaysNetworks – The Early Days

• Early networks were limited to character based information.Early networks were limited to character based information.• Communications between computers was not easy and Communications between computers was not easy and

required a host (no pun intended) of resources to accomplish required a host (no pun intended) of resources to accomplish the simplest data transfer.the simplest data transfer.

CCNA1-7 Chapter 1

Networks – TodayNetworks – Today

• Today’s networks carry multiple types of information through Today’s networks carry multiple types of information through many types of devices - many types of devices - SIMULTANEOUSLYSIMULTANEOUSLY..

• Voice, Video, Audio, Text, graphicsVoice, Video, Audio, Text, graphics

Silver and Diamond Cell Phone $1.3Million

Wind Energy Cell Phone Charger

CCNA1-8 Chapter 1

Networks – Today – A Global CommunityNetworks – Today – A Global Community

CCNA1-9 Chapter 1

Networks Supporting The Way We LiveNetworks Supporting The Way We Live

• The Internet has quickly become an integral part of our daily The Internet has quickly become an integral part of our daily routines.routines.

• Data networks that were once only used to transport Data networks that were once only used to transport business information are now used to improve our quality of business information are now used to improve our quality of life no matter where we live.life no matter where we live.

CCNA1-10 Chapter 1

Networks Supporting The Way We LiveNetworks Supporting The Way We Live

• In the course of the day,In the course of the day,Internet resources canInternet resources canhelp you.help you.

• IMIM - Instant Messaging: - Instant Messaging:• Internet Relay Chat (IRC) Internet Relay Chat (IRC)

• BlogsBlogs (Weblogs): (Weblogs):• Personal opinions on any conceivable subject.Personal opinions on any conceivable subject.

• PodcastingPodcasting::

Sharing recordings with a wide audience (Apple iPods)Sharing recordings with a wide audience (Apple iPods)• WikisWikis::

• A collaboration tool. Gives people the opportunity to work A collaboration tool. Gives people the opportunity to work together on shared documents.together on shared documents.

CCNA1-11 Chapter 1

Networks Supporting The Way We LearnNetworks Supporting The Way We Learn

• E-LearningE-Learning

CCNA1-12 Chapter 1

Networks Supporting The Way We LearnNetworks Supporting The Way We Learn

• Online discussions and access to resources.Online discussions and access to resources.

CCNA1-13 Chapter 1

Networks Supporting The Way We LearnNetworks Supporting The Way We Learn

• Tools - Packet TracerTools - Packet Tracer

CCNA1-14 Chapter 1

Networks Supporting The Way We WorkNetworks Supporting The Way We Work

• Business networks evolved to enable the transmission of Business networks evolved to enable the transmission of many different types of information services, including e-mail, many different types of information services, including e-mail, video, messaging, and telephony.video, messaging, and telephony.

• Different companies use different types of networks.Different companies use different types of networks.

CCNA1-15 Chapter 1

Networks Supporting The Way We WorkNetworks Supporting The Way We Work

CCNA1-16 Chapter 1

Networks Supporting The Way We WorkNetworks Supporting The Way We Work

CCNA1-17 Chapter 1

Networks Supporting The Way We PlayNetworks Supporting The Way We Play

• The entertainment and travel industries have made use of the The entertainment and travel industries have made use of the Internet to provide online gaming, music and movie Internet to provide online gaming, music and movie downloads, online travel bookings, hotel and car reservations downloads, online travel bookings, hotel and car reservations and much, much more.and much, much more.

CCNA1-18 Chapter 1

Networks Supporting The Way We PlayNetworks Supporting The Way We Play

• Some of the most innovative developments in network Some of the most innovative developments in network technology have come from the increasing demand for technology have come from the increasing demand for entertainment.entertainment.

CCNA1-19 Chapter 1

Communications – What is it?Communications – What is it?

• Communications can take many forms and occurs in many Communications can take many forms and occurs in many different environments.different environments.

• We establish rules, We establish rules, or protocolsor protocols, for communicating with each , for communicating with each other:other:

• Identify the sender and receiver.Identify the sender and receiver.• Agree on the method.Agree on the method.• Common language.Common language.• Speed and delivery of the message.Speed and delivery of the message.• Confirmation that the message was received.Confirmation that the message was received.

• Communications between individuals is successful if the Communications between individuals is successful if the meaning of the received message is the same as the meaning of the received message is the same as the meaning of the message that was sent.meaning of the message that was sent.

CCNA1-20 Chapter 1

Communications - QualityCommunications - Quality

• For data networks, we use the same basic criteria to judge For data networks, we use the same basic criteria to judge successful communication.successful communication.

• However, there are However, there are external factorsexternal factors that can affect the that can affect the message.message.

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

• The number of times the message has to The number of times the message has to change formchange form or or be be redirectedredirected or or re-addressedre-addressed..

• The number of The number of other messagesother messages being transmitted being transmitted simultaneously on the communication network.simultaneously on the communication network.

• The The amount of timeamount of time allotted for successful allotted for successful communication.communication.

CCNA1-21 Chapter 1

Communications - QualityCommunications - Quality

• There are also There are also internal factorsinternal factors that can affect successful that can affect successful communication.communication.

Message SizeMessage SizeMessage Message

ComplexityComplexity

Message Message ImportanceImportance

CCNA1-22 Chapter 1

Communications - QualityCommunications - Quality

• It is also more difficult to deliver a large, bulky package It is also more difficult to deliver a large, bulky package successfully and without damage than it is to deliver several successfully and without damage than it is to deliver several smaller packages.smaller packages.

CCNA1-23 Chapter 1

Network As A PlatformNetwork As A Platform

• All networks have All networks have 44 basic elements in common: basic elements in common:

Rules (protocols) Rules (protocols) to govern the handling of the message.to govern the handling of the message.

Messages Messages that travel from one device to another.that travel from one device to another.

Medium Medium that is used to interconnect devices and can that is used to interconnect devices and can transport the messages from one device to another.transport the messages from one device to another.

Devices Devices on the network that exchange messages.on the network that exchange messages.

CCNA1-24 Chapter 1

Network As A PlatformNetwork As A Platform

MessagesMessages take many forms. take many forms.

CCNA1-25 Chapter 1

Network As A PlatformNetwork As A Platform

Media Media on a network can be varied.on a network can be varied.

CCNA1-26 Chapter 1

Network As A PlatformNetwork As A Platform

Devices Devices on a network – Common Symbolson a network – Common Symbols

CCNA1-27 Chapter 1

Network As A PlatformNetwork As A Platform

Rules Rules on a network seem almost endless – but they’re not.on a network seem almost endless – but they’re not.

• Other Application Protocols:Other Application Protocols:• DNS, DHCP, FTPDNS, DHCP, FTP

• Some Other Protocols:Some Other Protocols:• TCP/IP Protocol Suite, Ethernet, Routing ProtocolsTCP/IP Protocol Suite, Ethernet, Routing Protocols

CCNA1-28 Chapter 1

Putting It all TogetherPutting It all Together

1. Converted to Binary.1. Converted to Binary.

2. NIC generates signals.2. NIC generates signals.

3. Passed among LAN devices.3. Passed among LAN devices.

4. Exit the local area (router).4. Exit the local area (router).

CCNA1-29 Chapter 1

Putting It all TogetherPutting It all Together

The many interconnected The many interconnected devices worldwide are often devices worldwide are often

represented by a cloud.represented by a cloud.

5. Bits are transmitted to 5. Bits are transmitted to devices that interconnect devices that interconnect the networks.the networks.

CCNA1-30 Chapter 1

Putting It all TogetherPutting It all Together

6. Passed among local 6. Passed among local devices at the destination.devices at the destination.

7. The destination device converts 7. The destination device converts the bits into human readable form.the bits into human readable form.

CCNA1-31 Chapter 1

Putting It all TogetherPutting It all Together

11 22 33 44

55

66 77

At each of these steps, there are At each of these steps, there are protocols that define the rules for protocols that define the rules for

device communication.device communication.

CCNA1-32 Chapter 1

Putting It All TogetherPutting It All Together

• Of course, it always helps to know what you’re doing.Of course, it always helps to know what you’re doing.

CCNA1-33 Chapter 1

Converged NetworksConverged Networks

• Traditional telephone, radio, television, and computer data Traditional telephone, radio, television, and computer data networks each have their own individual versions of the four networks each have their own individual versions of the four basic network elements. basic network elements.

CCNA1-34 Chapter 1

Converged NetworksConverged Networks

• Technology advances are enabling us to consolidate these Technology advances are enabling us to consolidate these disparate networks onto disparate networks onto one platformone platform..

• A platform defined as a A platform defined as a converged networkconverged network. .

CCNA1-35 Chapter 1

Converged NetworksConverged Networks

CCNA1-36 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

• The term The term Network ArchitectureNetwork Architecture::• Technologies that support the Technologies that support the infrastructureinfrastructure• Programmed services and protocolsProgrammed services and protocols that move the that move the

messages across that infrastructure.messages across that infrastructure.• There are There are 4 basic characteristics4 basic characteristics for networks in general to for networks in general to

meet user expectations:meet user expectations:• Fault toleranceFault tolerance• ScalabilityScalability• Quality of Service (QoS)Quality of Service (QoS)• SecuritySecurity

CCNA1-37 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

Fault ToleranceFault Tolerance

CCNA1-38 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

• Fault Tolerance:Fault Tolerance:• The Internet, in its early inception, was the result of The Internet, in its early inception, was the result of

research funded by the United States Department of research funded by the United States Department of Defense (DoD).Defense (DoD).

• Fault toleranceFault tolerance was the focus of the initial internetwork was the focus of the initial internetwork design.design.

• Early network researchers looked at the existing Early network researchers looked at the existing communication networks, which were primarily for the communication networks, which were primarily for the transmission of voice traffic, to determine what could be transmission of voice traffic, to determine what could be done to improve the fault tolerance level.done to improve the fault tolerance level.

CCNA1-39 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

Circuit Switched – Connection-Oriented NetworksCircuit Switched – Connection-Oriented Networks

CCNA1-40 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

Packet Switched – Connectionless NetworksPacket Switched – Connectionless Networks

CCNA1-41 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

Circuit SwitchedCircuit Switched Packet SwitchedPacket Switched

Connection-orientedConnection-oriented ConnectionlessConnectionless

Dedicated CircuitDedicated Circuit Shared CircuitShared Circuit

Guaranteed level of serviceGuaranteed level of service

(Bandwidth, QoS)(Bandwidth, QoS)Messages divided into packetsMessages divided into packets

Inefficient use of MediumInefficient use of Medium Efficient use of MediumEfficient use of Medium

Single path, no redundancySingle path, no redundancy Fault TolerantFault Tolerant, multiple possible , multiple possible pathspaths

CCNA1-42 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

ScalabilityScalability

CCNA1-43 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

• A good example of A good example of scalabilityscalability is the Tier architecture of the is the Tier architecture of the Internet.Internet.

Tier 2: Tier 2: Pay Tier 1 providers for Pay Tier 1 providers for connectivity and provide connectivity and provide

regional service. regional service.

Tier 1: Tier 1: ISPs provide national and international connections. (Verizon, Sprint, AT&T, NTT, cable systems, etc.)

Internet Internet BackboneBackbone

Tier 3: Provide service to end Tier 3: Provide service to end users and are usually connected users and are usually connected

through Tier 2 providers.through Tier 2 providers.

CCNA1-44 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

• Additional providers can be added relatively easily with no Additional providers can be added relatively easily with no disruption of current services. disruption of current services. THAT is scalability!THAT is scalability!

Internet Internet BackboneBackbone

CCNA1-45 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

Quality of Service (QoS)Quality of Service (QoS)

CCNA1-46 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

Quality of Service (QoS)Quality of Service (QoS)

CCNA1-47 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

Quality of Service (QoS)Quality of Service (QoS)

CCNA1-48 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

SecuritySecurity

CCNA1-49 Chapter 1

The Architecture of the InternetThe Architecture of the Internet

SecuritySecurity

Ensure Confidentiality: Ensure Confidentiality: Strong authentication and Strong authentication and

appropriate encryptionappropriate encryption

Communication Integrity: Communication Integrity: Digital Signatures, Hashing Digital Signatures, Hashing

Algorithms, ChecksumAlgorithms, Checksum

Ensuring Availability: Ensuring Availability: Combating virus attacks, Combating virus attacks,

Firewalls, Redundant Firewalls, Redundant ArchitectureArchitecture

CCNA1-50 Chapter 1

Trends in NetworkingTrends in Networking

• Increasing number of mobile usersIncreasing number of mobile users• Proliferation of network capable devicesProliferation of network capable devices• Expanding range of servicesExpanding range of services

CCNA1-51 Chapter 1

CareersCareers

• Information Technology and networking careers are growing Information Technology and networking careers are growing and evolving as fast as the underlying technologies and and evolving as fast as the underlying technologies and services. As networks increase in sophistication, the demand services. As networks increase in sophistication, the demand for people with networking skills will continue to grow. for people with networking skills will continue to grow.

CCNA1-52 Chapter 1

““IT” is not the Network – it IS the users.IT” is not the Network – it IS the users.

• The IT (Information The IT (Information Technology) department is not Technology) department is not the network.the network.

• The network is the users and The network is the users and their:their:

• NeedsNeeds• ExpectationsExpectations• RequirementsRequirements• UsesUses

If IT doesn’t find a way, If IT doesn’t find a way, the users will!the users will!

CCNA1-53 Chapter 1

A Shift in AttitudeA Shift in Attitude

• Old school IT doesn’t workOld school IT doesn’t workany more.any more.

• We don’t support MACs.We don’t support MACs.• We can’t allow that applicationWe can’t allow that application

on our network.on our network.• We can’t give them accessWe can’t give them access

on our network.on our network.• We have too much to do already.We have too much to do already.• We don’t support that.We don’t support that.• You don’t know about networks, so we can’t do that.You don’t know about networks, so we can’t do that.• That would breach our securityThat would breach our security

CCNA1-54 Chapter 1

Technical and Soft SkillsTechnical and Soft Skills

• Networking professionalsNetworking professionalsneed more knowledge andneed more knowledge andskills today than ever before.skills today than ever before.

• Tomorrow’s IT professionalsTomorrow’s IT professionalswill need even more.will need even more.

• Just as important, andJust as important, andsometimes even moresometimes even moreimportant, are the soft skills:important, are the soft skills:

• AttitudeAttitude• EnthusiasmEnthusiasm• Communications skillsCommunications skills• Professionalism and EthicsProfessionalism and Ethics