1. networking konsep

7/21/2019 1. Networking Konsep

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2000, Cisco Systems, Inc. 2-1

InternetworkingConcepts Overview


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2000, Cisco Systems, Inc. www.cisco.com ICND v1.12-2

Objectives

On completion of this chapter, you will beable to perform the following tasks:

Describe how data traffic is exchangedbetween 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 agiven set of network requirements.


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Defining Componentsof the Network

Main OfficeBranch Office

HomeOffice

MobileUsers

Internet


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Floor 2

Floor 1

Server Farm

Defining Components ofthe Network (cont.)

BranchOffice

Telecommuter

ISDN

Remote Campus


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Network Structure Defined byHierarchy

DistributionLayer

Core Layer

AccessLayer


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Access Layer Characteristics

End-station entry point to the network

Access Layer


7/44 2000, Cisco Systems, Inc. www.cisco.com ICND v1.12-7

Distribution LayerCharacteristics

Access layeraggregation point

Traffic routingBroadcast/multicastdomains

Media translationSecurity

Possible point for remote access

Distribution Layer



Core Layer Characteristics

Fast transport to enterprise services

No packet manipulation

Core Layer



OSI Model Overview

Application(Upper)Layers

Session

Presentation

Application



OSI Model Overview

Data FlowLayers

Transport

Data-Link

Network

Physical

Application(Upper)Layers

Session

Presentation

Application



Role of Application Layers

TelnetFTP

User Interface

Examples

Application



TelnetFTP

ASCIIEBCDICJPEG

User Interface

How data is presented

Special processingsuch as encryption

Examples

Presentation

Application




TelnetFTP

ASCIIEBCDICJPEG

Keeping differentapplicationsdata separate

User Interface



Operating System/Application Access

Scheduling

Examples

Session

Presentation

Application




Keeping differentapplications dataseparate

User interface



TelnetFTP

ASCIIEBCDICJPEG

Operating System/Application Access

SchedulingTransport

Data-Link

Network

Physical

Examples

Session

Presentation

Application




Role of Data Flow Layers

EIA/TIA-232

V.35

Examples

PhysicalMove 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 framesAccess to media using MAC address

Error detection not correction

Move bits between devices


pin-out cables



802.3 / 802.2HDLC

EIA/TIA-232V.35

IPIPX

Examples


Network

Data Link

Physical






pin-out cables

Provide logical addressing thatrouters 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 thatrouters 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



Error detection, not correction


Specifies voltage, wire speed, andpinout cables

Transport

Data-Link

Physical

NetworkProvide logical addressing thatrouters use for path determination



Encapsulating 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 Data

LLC Hdr + IP + TCP + Upper-Layer Data

MACHeader

IP + TCP + Upper-Layer Data

LLCHeader

TCP+ Upper-Layer Data

IPHeader

Upper-Layer Data

TCPHeader

0101110101001000010

Transport

Data-Link

Physical

Network

Presentation

Application

Session



Application

Presentation

Session

Transport

Network

Data-Link

Physical

OSI Model PDU Functional Responsibilities Examples

Written Exercise 1: OSI Model


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Physical Layer Functions

Defines

Media type

Connector type

Signaling type

Eth

erne

t

802.3

V . 3

5

Physical

EIA

/TIA

-232


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Physical Layer: Ethernet/802.3

Hub

Hosts

Host

10Base2Thin Ethernet

10Base5Thick Ethernet

10BaseTTwisted Pair


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Hubs Operate at Physical Layer

A B C D

Physical

All devices are in the same collision domain.

All devices are in the same broadcast domain.

Devices share the same bandwidth.


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Hubs: One Collision Domain

More end stations means

more collisions.CSMA/CD is used.


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Data-Link Layer Functions

Defines:

Physical source anddestination addresses

Higher-layer protocol(service access point)associated with frame

Network topology

Frame sequencingFlow control

Connection-orientedor connectionless

Data-Link

Physical

EIA/TIA-232V.35

Eth

erne

t

F r a m

e R

e l a

y

HDLC

802.2

802.3


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DataSource Address FCSLengthDestination Address

Variable266 4

0000.0C xx.xxxx

VendorAssigned

IEEE Assigned

MAC Layer802.3

Data-Link Layer Functions (cont.)

Preamble

Ethernet IIuses Typehere and

does not use802.2.

MAC Address

8Number of Bytes


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DataDestination

SAP

Source

SAP

DataSourceAddress

FCSLengthDestinationAddress

Variable11

802.2 (SAP)

MAC Layer802.3

Data-Link Layer Functions (cont.)

Control

1 or 2

3 2

Preamble

DataDestinationSAP

AA

Source SAP

AA

Variable11

802.2 (SNAP)

Control

03

1 or 2

OR

OUIID

Type

Number of Bytes

Number of Bytes

S ih dBid O


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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

OR1 2 3 1 24


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Switches

Each segment is itsown collision domain.

Broadcasts areforwarded to allsegments.

Memory

Switch


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Network Layer Functions

Defines logicalsource anddestination

addressesassociated with aspecific protocol

Defines pathsthrough network

Interconnectsmultiple data links

Network

IP, IPX

Data-Link

Physical

EIA/TIA-232V.35

Ethe

rne

t

F r a m e

R e

l a y

HDLC

802.2

802.3


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DataSource

Address

Destination

Address

IP

Network Layer Functions (cont.)

Header

172.15.1.1

NodeNetwork

LogicalAddress

Network Layer End-Station Packet


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11111111111111110000000000000000

10101100000100000111101011001100

BinaryMask

BinaryAddress

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 INTMetric

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 is required.

Configured information identifies paths to networks.



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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

Internet

Telecommuter

Branch Office

Modem or ISDN Terminal Adapter

Mobile User

Main Office


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Transport Layer Functions

Distinguishes betweenupper-layer applications

Establishes end-to-end

connectivity betweenapplications

Defines flow control

Provides reliable orunreliable services fordata transfer

Network

IPXIP

Trans

port

SPXTCP UDP

RliblT tL


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Reliable Transport LayerFunctions

Synchronize

Acknowledge, Synchronize

Acknowledge

Data Transfer

(Send Segments)

Sender Receiver

Connection EstablishedConnection EstablishedConnection EstablishedConnection Established


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Network Device Domains

Hub Bridge Switch Router

Collision Domains:

1 4 4 4

Broadcast Domains:

1 1 1 4


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Product SelectionConsiderations

Functionality and features you need today

Capacity and performance

Easy installation and centralized managementNetwork resiliency

Investment protection in existing infrastructure

Migration path for change and growthSeamless access for mobile users andbranch offices

P d Sl i


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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.)

Costper

Month

Usage

Leased Line, T1

Modem/ISDN

Frame Relay

0

P d Sl i


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Product SelectionConsiderations (cont.)

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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Summary

After completing this chapter, you should beable to perform the following tasks:

Describe how data moves through a network.

Identify the roles and functions of routers,switches, and hubs, and specify where eachdevice best fits in the network.

Select the appropriate Cisco equipment for anetwork that combines switching, routing, andremote access requirements.

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