internetworking concepts overview_2

8/9/2019 Internetworking concepts overview_2

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2000, Cisco Systems, Inc. 2-1

Chapter 2

InternetworkingConcepts Overview


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2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a2-2


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ObjectivesObjectives

On completion of this chapter, you will be ableto perform the following tasks:

Describe how data traffic is exchanged between

source and destination devices Identify the roles and functions of a hub, switch, and

router, and where they best fit in the network

Select the appropriate Cisco equipment for a given

set of network requirements


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Defining Componentsof the Network

Defining Componentsof the Network

Main OfficeBranch Office

HomeOffice

MobileUsers

Internet


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Floor 2

Floor 1

Server Farm

Defining the Componentsof a Network (cont.)

Defining the Componentsof a Network (cont.)

BranchOffice

Telecommuter

ISDN

Remote Campus


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Network Structure Defined byHierarchy

Network Structure Defined byHierarchy

DistributionLayer

Core Layer

AccessLayer


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Access Layer CharacteristicsAccess Layer Characteristics

End station entry point to the network

Access Layer



Distribution LayerCharacteristics

Distribution LayerCharacteristics

Access LayerAggregation Point

Routes traffic Broadcast/Multicast

Domains

Media Translation Security

Possible point for remote access

Distribution Layer



Core Layer CharacteristicsCore Layer Characteristics

Fast transport to enterprise services

No packet manipulation

Core Layer



OSI Model OverviewOSI Model Overview

Application(Upper)Layers

Session

Presentation

Application



OSI Model OverviewOSI Model Overview

Data FlowLayers

Transport Layer

Data Link

Network Layer

Physical

Application(Upper)Layers

Session

Presentation

Application



Role of Application LayersRole of Application Layers

TelnetFTP

User Interface

EXAMPLES

Application



TelnetFTP

ASCIIEBCDICJPEG

User Interface

How data is presentedSpecial processingsuch as encryption

EXAMPLES

Presentation

Application




TelnetFTP

ASCIIEBCDICJPEG

Keeping differentapplicationsdata separate

User Interface


Operating System/Application Access

Scheduling

EXAMPLES

Session

Presentation

Application




Keeping differentapplicationsdata separate

User Interface


TelnetFTP

ASCIIEBCDICJPEG

Operating System/Application Access

SchedulingTransport Layer

Data Link

Network Layer

Physical

EXAMPLES

Session

Presentation

Application




Role of Data Flow LayersRole of Data Flow Layers

EIA/TIA-232V.35

EXAMPLES

Physical

Move bits between devices Specifies voltage, wire speed and

pin-out cables



802.3 / 802.2HDLC

EIA/TIA-232V.35

EXAMPLES


Data Link

Physical

Combines bits into bytes and

bytes into frames Access to media using MAC address Error detection not correction


pin-out cables



802.3 / 802.2HDLC

EIA/TIA-232V.35

IPIPX

EXAMPLES


Network

Data Link

Physical




pin-out cables

Provide logical addressing whichrouters use for path determination



TCPUDPSPX

802.3 / 802.2HDLC

EIA/TIA-232V.35

IPIPX

EXAMPLES


Transport

Data Link

Physical

Reliable or unreliable delivery Error correction before retransmit




pin-out cables

NetworkProvide logical addressing whichrouters use for path determination



TCPUDPSPX

802.3 / 802.2HDLC

EIA/TIA-232V.35

IPIPX

Presentation

Application

SessionEXAMPLES


Reliable or unreliable delivery Error correction before retransmit




pin-out cables

Transport

Data Link

Physical

NetworkProvide logical addressing whichrouters use for path determination



Encapsulating DataEncapsulating Data

Transport

Data Link

Physical

Network

Upper Layer Data

Upper Layer DataTCP Header

DataIP Header

DataLLC Header

0101110101001000010

DataMAC Header

Presentation

Application

Session

Segment

Packet

Bits

Frame

PDU

FCS

FCS



Upper Layer Data

De-encapsulating DataDe-encapsulating Data

LLC Hdr + IP + TCP + Upper Layer Data

MACH

eader

IP + TCP + Upper Layer Data

LLCHe

ader

TCP+ Upper Layer Data

IPHead

er

Upper Layer Data

TCPH

eader

0101110101001000010

Transport

Data Link

Physical

Network

Presentation

Application

Session


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Application

Presentation

Session

Transport

Network

Data Link

Physical

OSI Model PDU Functional Responsibilities Examples

Written Exercise: OSI ModelWritten Exercise: OSI Model


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Physical Layer FunctionsPhysical Layer Functions

Defines

Media type

Connector type

Signaling type

Eth

erne

t

802.3

V.35

Physic

al

EIA/TIA

-232


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Physical Layer: Ethernet/802.3Physical Layer: Ethernet/802.3

Hub

Hosts

Host

10Base2Thin Ethernet

10Base5Thick Ethernet

10BaseTTwisted Pair


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Hubs Operate at Physical layerHubs Operate at Physical layer

A B C D

Physical

All devices in the same collision domain

All devices in the same broadcast domain

Devices share the same bandwidth


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Hubs: One Collision DomainHubs: One Collision Domain

More end stations means

more collisions CSMA/CD is used


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Data Link layer FunctionsData Link layer Functions

Defines

Physical source anddestination addresses

Higher layer protocol(Service Access Point)associated with frame

Network topology

Frame sequencing Flow control

Connection-orientedor connectionless

DataL

i nk

Physical

EIA/TIA-232v.35

Eth

erne

t

Fram

eR

elay

HDLC

802.2

802.3


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DataSource add FCSLengthDest add

Variable266 4

0000.0C xx.xxxx

Vendorassigned

IEEE assigned

MAC Layer - 802.3

Data Link Layer Functions (cont.)Data Link Layer Functions (cont.)

Preamble

Ethernet IIuses Typehere and

does not use802.2.

MAC Address

8# Bytes


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DataDest

SAP

Source

SAP

DataSource add FCSLengthDest add

Variable11

802.2 (SAP)

MAC Layer - 802.3

Data Link Layer Functions (cont.)Data Link Layer Functions (cont.)

Ctrl

1 or 2

3 2

Preamble

DataDest SAP

AASource SAP

AA

Variable11

802.2 (SNAP)

Ctrl

03

1 or 2

OR

OUIID

Type

# Bytes

# Bytes

S i h d B id OS it h d B id O t


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Each segment has its own collision domain

All segments are in the same broadcast domain

Data Link

Switches and Bridges Operateat Data Link Layer

Switches and Bridges Operateat Data Link Layer

OR1 2 3 1 24


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SwitchesSwitches

Each segment has itsown collision domain

Broadcasts areforwarded to allsegments

Memory

Switch


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Network Layer FunctionsNetwork Layer Functions

Defines logicalsource anddestination

addressesassociated with aspecific protocol

Defines pathsthrough network

Interconnectsmultiple data links

Networ k

IP, IPX

DataLi n

k

Physic

al

EIA/TIA-232v.35

Ethe

rne

t

Fram

eR

elay

HDLC

802.2

802.3


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DataSource

address

Destination

address

IP

Network Layer Functions (cont.)Network Layer Functions (cont.)

Header

172.15.1.1

NodeNetwork

LogicalAddress

Network Layer End Station Packet


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1111111111111111 0000000000000000

1010110000010000 0111101011001100

BinaryMask

inaryddress

172.16.122.204 255.255.0.0

172 16 122 204

255

Address Mask

255 0 0

Network Host


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Routing Table

NET INT Metric

124

S0S0E0

100

1.0 4.0

1.3

E0

4.3

S0

2.2

E0

2.1

S0

4.1

4.2

1.1

1.2

Routing Table

NET INT Metric

124

E0S0S0

001

Logical addressing allows for hierarchical network Configuration required

Uses configured information to identify paths to networks


OR O h


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Routers: Operate at theNetwork Layer

Routers: Operate at theNetwork Layer

Broadcast control

Multicast control

Optimal pathdetermination

Traffic management

Logical addressing

Connects to WANservices


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Using Routers to ProvideRemote Access

Using Routers to ProvideRemote Access

Internet

Telecommuter

Branch Office

Modem or ISDN TA

Mobile User

Main Office


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Transport Layer FunctionsTransport Layer Functions

Distinguishes betweenupper layer applications

Establishes end-to-end

connectivity betweenapplications

Defines flow control

Provides reliable orunreliable services fordata transfer

Networ

k

IPXIP

Trans

port

SPXTCP UDP

R li bl T t LR li bl T t L


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Reliable Transport LayerFunctions

Reliable Transport LayerFunctions

Synchronize

Acknowledge, Synchronize

Acknowledge

Data Transfer

(Send Segments)

Sender Receiver

Connection EstablishedConnection EstablishedConnection EstablishedConnection Established


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Network Device DomainsNetwork Device Domains

Hub Bridge Switch Router

Collision Domains:

1 4 4 4

Broadcast Domains:

1 1 1 4


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Choosing a Cisco ProductChoosing a Cisco Product

DistributionLayer

Core Layer

AccessLayer

SP d S l i


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Product SelectionConsiderations

Product SelectionConsiderations

Provides functionality and features you need today

Capacity and performance

Easy installation and centralized management

Provides network resiliency

Investment protection in existing infrastructure

Migration path for change and growth

Seamless access for mobile users andbranch offices

P d t S l tiP d t S l ti


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First select WANtechnology solutionsbased on the following:

Availability of service

Bandwidth requirement

Cost

Second, choose productsthat support selected WANsolutions

Product SelectionConsiderations (cont.)


Costp

er

Month

Usage

Leased Line, T1

Modem/ISDN

Frame Relay

0

Prod ct SelectionProduct Selection


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1544

128

64

56

19.2

9.6

4.8

Determine applications that you want to run

ISDN,ISDN,Frame RelayFrame Relay

Old ModemOld Modem Telnet

New ModemNew Modem

Web Browsing

Voice

Video, Multimedia

E-Mail, File Transfer

Leased Line,Leased Line,Frame Relay,Frame Relay,XDSLXDSL

kbps


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Selection Issues:

Need for 10 Mbps or 100 Mbps on media

Port density

Need for management console

Easy Operations

Cisco 1500Micro Hub

CiscoFastHub300

Cisco 1528Micro Hub 10/100

CiscoFastHub400

CiscoFastHub200

CiscoFastHub100

Cisco Hub ProductsCisco Hub Products


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Selection Issues:

Need for 10 Mbps, 100 Mbps, or 1000 Mbps onmedia

Need for trunking and inter-switch links

Workgroup segmentation (VLANs)

Port density needs

Different user interfaces

Desktop/WorkgroupSolutions

WiringCloset/Backbone

Solutions

Cisco 1548 MicroSwitch 10/100

Catalyst3000 series

Catalyst 2900series XL

Catalyst1900/2820 series

Catalyst2900 series

Catalyst

5000 series

Catalyst8500 series

Catalyst Switch ProductsCatalyst Switch Products

D N t D l t O fl T tD N t D l t O fl T t


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Do Not DeleteOverflow Texton Notes Page



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Selection Issues:

Scale of the routing features needed

Port density/variety requirements

Capacity and performance Common user interface

Cisco700/800Series

Cisco1600/1700

Series

Cisco2500

Series

Cisco3600Series

AS

5000Series

Small Office Solutions

Branch Office Solutions

Central Site Solutions

Cisco

12000 GSRSeries

Cisco4000

Series

Cisco7000

Series

Home Office Solutions

Cisco2600Series

Cisco Router ProductsCisco Router Products

D N t D l t O fl T tD N t D l t O fl T t


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Visual ObjectiveVisual Objective

Use the product selection tool to

select Cisco Equipment


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