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Sidevõrgud IRT 0020

loeng 2 18. sept. 2005

Avo Otstelekommunikatsiooni õppetoolraadio- ja sidetehnika instituut

avots@lr.ttu.ee

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Backbone network design layers

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Layering

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Ülemise ja alumised kihidLower three layers are hop-by-hopNext two layers are end-to-endApplication

Transport

Network

Datalink

Physical

Application

Transport

Network

Datalink

Physical

Network

Datalink

Physical

Physical medium

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Andmeülekanne (loogiline)

applicationtransportnetwork

linkphysical

applicationtransportnetwork

linkphysical application

transportnetwork

linkphysical

applicationtransportnetwork

linkphysical

networklink

physical

data

data

data

transport

transport

ack

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Andmeülekanne (füüsiline)

applicationtransportnetwork

linkphysical

applicationtransportnetwork

linkphysical application

transportnetwork

linkphysical

applicationtransportnetwork

linkphysical

networklink

physical

data

data

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Sõnumiülekanne

datagram

applicationtransportnetwork

linkphysical

applicationtransportnetwork

linkphysical

source destinationMMMM

HtHtHnHtHnHl

MMMM

HtHtHnHtHnHl

messagesegment

frame

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VahekihidTelnet FTP

packetradio

coaxial cable

fiberoptic

HTTP

HTTPTelnet FTP

packetradio

coaxial cable

fiberoptic

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Funktsioonijaotus• The application knows the requirements

best, place functionality as high in the layer as possible

• If the application can implement a functionality correctly, implement it at a lower layer only as a performance enhancement

• Think twice before implementing a functionality that you believe that is useful to an application at a lower layer

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Töökindlus

• Solution 1: make each step reliable, and then concatenate them

• Solution 2: end-to-end check and retry

L1

L2

L1

sender receiver

L1

L2

router

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Töökindluse tagamine

• The receiver has to do the check anyway!• Thus, full functionality can be entirely

implemented at the upper layer; no need for reliability from lower layers

• Is there any need to implement reliability at lower layers?

L1

L2

L1

sender receiver

L1L2

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Routed Backbone

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Collapsed backbone

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Central Parking’s collapsed backbone

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ATM Virtual Circuits

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ATM Encapsulation

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Protokollidhttp://www.private.org.il/tcpip_rl.htmlhttp://www.eix.co.uk/Ethernet/

http://www.mfaforum.org/education/atm_presentations.shtml

http://www.mfaforum.org/education/atm_cs.shtml

http://www.mfaforum.org/tech/superdemo_2004.pdf

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ISO OSI vs DoD mudel

Process/Application

Host-to-HostInternet

Network Access

7654321

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T

T G T

T R R

T T

T

Võrkude ja teenuste ühendamine

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N. AmericaN. America

Central & S. AmericaCentral & S. America

W. & E. EuropeW. & E. Europe

Middle East &Middle East & AfricaAfrica

APACAPAC2.5 & 5.8 GHz2.5 & 5.8 GHz

2.5, 3.5 & 5.8 GHz2.5, 3.5 & 5.8 GHz

3.5 & 5.8 GHz3.5 & 5.8 GHz

3.5 & 5.8 GHz3.5 & 5.8 GHz

3.5 & 5.8 GHz3.5 & 5.8 GHz

Licensed Bands• 2.5GHz (2.3-2.4; 2.5-2.7)• 3.5GHz (3.3-3.7)

Unlicensed Band• 5.8GHz (5.25-5.85)

Spectrum Usage

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Kihtide vahelised seosed

rakendus

esitlus

seanss

transport

võrk

kanal

füüsiline

Võrguteenus

Võrgurakenduse teenus

Transporditeenus

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Mudeli täiendused

DiffServ

7 Application

6 Presentation

5 Session

4 Transport

3 Network

2 Data Link

1 Physical

e. g. Workflow

G.711 / G.723.1 / G.729

H.323 / H.450 / RTP

TCP / UDP

IP

MAC

Transmission Medium

802.1 D

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Simple Mail Transfer Protocol• RFC0821 (august 1982) J. Postel,

RFC2821 (aprill, 2001)

• Sõnumite töökindlaks saatmiseks• Klient-server mudel• Ühendusele orienteeritud ja kinnitustega

protokoll• TCP port 25

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Lõpulingid• Kõik RFC-d:

http://www.ietf.org/iesg/1rfc_index.txt• Infotehnoloogia reeglid Eesti keele ja

kultuuri keskkonnas EVS 8:2000http://www.eki.ee/itstandard/sisukord.html

• www.ieee.org

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Kihid

7654321 Füüsiline (ühendus)

Kanal

Võrk

Transport

Seanss

Esitlus

Rakendus Application

Presentation

Session

Transport

Network

Data link

Physical

SSL, WSP

RFC 791 IP,RFC 792 ICMP

TCP RFC 793, UDP RFC 768

WAE, HTTP, RFC821,822

ISO 8859-15

IEEE 802.11a

Cat5, RS-232D

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Physical Network

Transmission NetworkCPE CPE

Physical Network Physical Network

Transmission Network

SwitchingNetwork

Application

Layer

Service

Layer

Transmission

Layer

Physical

Layer

PhysicalInterface

LogicalInterface

UNI UNI

NNI NNI

NNI

NNI NNI

ServiceAccessPoint

APP APP

SwitchingNetwork

SwitchingNetwork

ServiceNetwork

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Service

Access

Service Logic

ServiceIndependent

Block

Service Switch

Service

Control

Service

Switching

Service

Access

ServiceIndependent

Block

Service Switch Service Switch Service Switch

Service Logic

Service

Access

Service

Access

Service

Access

Service

Access

Service

Components

ServiceIndependent

Block

ServiceIndependent

Block

ServiceIndependent

Block

Call/

Session

Call/

Session

Call/

Session

Call/

Session

Call/

Session

Call/

Session

Call/

Session

Session Control

(Circuit

Switching control)

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Transmission

Network

Packet

Switching Network

ISP

Applications

CPE CPETransmission

Network

Transmission

Network

Packet

Switching Network

ISP

Applications

ISP

Applications

Application

Layer

Network

Layer

Transmission

Layer

PhysicalInterface

LogicalInterface

IP IPIP

NNI NNI

ServiceAccessPoint

APP APPServer Server Server

ServerClient

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ATerminal

B Terminal

APortal B

Portal

TransmissionAccess Access

Session Service

Control Service

A Home Service B Home ServiceA User Service Management

B User ServiceManagement

TransmissionAccess Service Access Service

Terminal TerminalTelecom basic service/call control

Off-line customer management

Extended call control and IN charging

Linear Service Architecture in Legacy Network: Static Services

Two-Dimension Service Architecture in NGN: Active Services

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Link• http://www.mmwave.com/pdf/

Alvarion.pdfKõik RFC-d:http://www.ietf.org/iesg/1rfc_index.txt

• Infotehnoloogia reeglid Eesti keele ja kultuuri keskkonnas EVS 8:2000http://www.eki.ee/itstandard/sisukord.html

• www.ieee.org