Chapter1 Mang May Tinh Gioi Thieu

8/6/2019 Chapter1 Mang May Tinh Gioi Thieu

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Chng 1.Mng my tnh v nhng khi nim m u

Chapter 1. Introduction to Computer Network, OSI, TCP/IP Reference Model 2

Ch1. Mng my tnh v nhng khi nim m u

1.1 - Mng my tnh v ng dng trong i sng.

1.2 - Phn loi mng (network taxonomy).

1.3 - Giao thc mng (software).

1.4 - Cc m hnh tham chiu (reference models).

1.5 - Chun mng my tnh (network standards).1.6 - H iu hnh trong mi trng mng.

1.7 - Mng Internet.


1.1. Mng my tnh v ng dng trong i sng

Mng my tnh (computer network) l h thng bao gmnhiu h my tnh n l (nt mng) c kt nivi nhautheo kin trc no v c kh nng trao i thng tin. Kt ni (interconnected): dy (wire), sng (wave)

Kin trc (architecture): cch thc kt ni v trao i thng tin.

Nt mng (node): host, workstation, network component

Li ch ca mng: Chia s, trao i thng tin.

Tng cng sc mnh ca h thng (distributed system, parallelsystem).


ng dng ca mng my tnh trong i sng

Mng ni b (cquan, to nh) Chia s ti nguyn (my in, cng, chng trnh).

Lin lc trong mng ni b cquan (local mail).

Cung cp dch v (m hnh client/server).

Web, Email, search engine, tin tc. Thng mi in t (ecommerce electronic commerce).

People online communication.

Chatting, conference

B GD hp qua mng v tuyn sinh 2005, 12/2004.

in thoi (PSTN, Mobile).

Chnh ph in t (egovernment)


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Chia s ti nguyn my in

CS before 2003 CS since 2003


Cc yu t ca mng my tnh

ng truyn vt l (physical media) Truyn tn hiu gia cc h thng.Hu tuyn (cable) v v tuyn (wireless).Di thng (bandwidth):

Di tn s cho php truyn. i khi c s dng m ch lng d liu cho php truyn

(throughput)!?

Tc (speed) hay thng lng (throughput): S lng bit truyn c trong mt giy (bps). S lng thay i tn hiu trong mt giy (baud).

Kin trc mng (network architecture)Hnh trng mng (topology).Giao thc (protocol).







1.5 - Chun mng my tnh (network standards).

1.6 - H iu hnh trong mi trng mng.

1.7 - Mng Internet.


1.2. Phn loi (network classification, taxonomy)

Theo topo mng Broadcast: Truyn qung b.

Point-to-point (switched): Truyn im-im.

Theo k thut truyn (transmission technique)

Circuit-switched Packet-switched

Message-switched

Theo quy m (scale)

LAN

MAN

WAN


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Topology (broadcast & point-to-point)


Circuit switching

Khi hai nt mun traoi thng tin thitlp knh (circuit).

Knh c gi ringcho hai nt cho ti khikt thc phin trao

i. VD: Mng in thoi.


Cc giai on ca circuit switching

circuit

establishment

DATA

datatransmission

circuittermination

Host 1 Host 2Node 1 Node 2

propagation delayfrom Host 1to Node 1

propagation delayfrom Host 2To Host 1

processing delay at Node 1


Packet switching

D liu c chia thnh cc gi tin (packet).Mi gi u c phnthng tin iu khin (header, trailer) cho bit ngun gi, ch nhn

Cc gi tin c th n v i theo nhng ng khc nhau dnknh (multiplexing), c lu tr ri chuyn tip khi i qua nttrung gian (store & forward).

Header Data Trailer

101001.1010001101011011110.11001

packet


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Packet switching: Datagram & Virtual Circuit

Host A

Host B

Host E

Host D

Host C

Node 1 Node 2

Node 3

Node 4

Node 5

Node 6 Node 7

Virtual-Circuit packet switching

Vd: ATM Network


Taxonomy summary

circuit-switchednetworks

(vd. telephone)

communicationnetworks

switchednetworks

broadcastnetworks(vd. Radio,

Broadcast TV)

packet-switchednetworks

datagramnetworks

(vd. Internet)

virtual circuit-switchednetworks

(vd. ATM)

FDM TDM









1.7 - Mng Internet.


1.3. Network Software (Protocol)

Giao thc (protocol): Tp hp cc quy tc giao tip giacc h my tnh.

M hnh giao thc mng hin nay tun theo kin trc phntng (layer architecture).

Mi tng m nhn nhng chc nng nht nh. Ch c tng dui cng l giao tip trc tip vi nhau.

Mt tng t tng 2 trln ch giao tip vi nhiu nht hai tng(k trn, k di).

Thng tin truyn t tng N ca h thng 1 sang tng N ca hthng 2 phi truyn qua cc tng N-1N-21 ca hthng 1 v cc tng 12N-1 ca h thng 2.


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Mailing system

Letter

Letter AddressedEnvelope

Addressed

Envelope


Philosopher-Translator-Secretary Layers


Unix Operating System Layers

Applications

Libraries

System Calls

Kernel


M hnh trao i dliu gia cc tng {1}


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M hnh trao i dliu gia cc tng {2}

Data

Data

(N+1) PDU

(N+1) PCI

(N) PCI

User

(N+1) Layer

(N) Layer

PCI Protocol Control Information

PDU Protocol Data Unit


Connectionless v connection-oriented

Giao thc truyn thng c chia lm hai loi:

Truyn tin c lin kt (connection-oriented): 3 giai on Thit lp lin kt (handshaking).

Truyn d liu (data transferring). C cc cch kim sot li

Hu b lin kt (terminating).

Truyn thng khng lin kt (connectionless): ch c giai

on truyn d liu. Thng s dng cho cc tng thp, ng truyn c tin cy

cao.









1.7 - Mng Internet.


1.4. Cc m hnh tham chiu (Reference Models)

Open System Interconnection Reference Model

(OSI Reference Model)

a ra bi ISO (International Organization for Standardization)nm 1984.

M hnh tham chiu l thuyt cho cc h thng mni chung.

7 tng: Physical, Data Link, Network, Transport, Session,Presentation, Application.

TCP/IP Reference Model

S dng cho mng Internet.

4 tng: Host-to-network, Internet, Transport, Application.


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OSI layers

Application

Presentation

Session

Transport

Network

Data Link

Physical

ng dng

Trnh din

Phin

Giao vn

Mng

Lin kt d liu

Vt l

011010100011001111

System #1 H thng#2

7

6

5

4

3

2

1

All

People

Seem

To

Need

Data

Processing


Layer 1: The Physical Layer

Ch c tng vt l ca hai h thng c kt nivtruyn thng trc tip vi nhau (wire/wireless).

Cc c t vt l (in, in t) nhm m bos kt ni v truyn tn hiu gia hai h thng.

Mt s yu t:Cp truyn (Cable).

Mc in th (voltage levels).Thi gian bin thin hiu in th.

Chu k tn hiu, khong cch


Layer 2: The Data Link Layer

Bin d liu th nhn c t tng vt l thnh d liu ccu trc logic c th hn. Framing.

001101010 Khung (frame) c cu trc.

Physical Addressing.

D liu n t u? My tnh no gi n? D liu cn phi gi tip i u?

m bo s tin cy ca tn hiu truyn gia hai tng vt l. Kim sot li (error control).

Kim sot lung (flow control).

Bao gm hai tng con (LLC v MAC).


Layer 3: The Network Layer

Chn ng i gia cc nt mng (path-selection).

iu khin lung mng con (subnet flow control).

Ct hp d liu (fragmentation & reassembly).

Kt ni cc mng c kin trc khc nhau.


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Layer 4: The Transport Layer

Tng trn cng ca qu trnh truyn d liu.

m bo d liu c truyn thng sut v tin cygia hai h thng (2 end-systems).Ct/hp d liu (fragmentation/reassembly).

Kim sot li, kim sot lung (error detection andrecovery, information flow control).

Thit lp, qun l cc knh lin lc (virtual circuits).Dn knh (multiplexing).


Layer 5: The Session Layer

Tng di cng trong s cc tng thao tc trn dliu nhn v (application).

Thit lp v qun l cc phin truyn thng giahai h thng.Chng thc (security authentication).

Thit lp lin kt (connection establishment).

Hu b lin kt (connection release).Phn hi (acknowledgement).

Truyn li (data retransmission).


Layer 6: The Presentation Layer

m bo thng tin truyn t ng dng ca h thngtruyn c th c c bi ng dng ca h thngnhn.C php v ng ngha ca d liu (syntax & semantic).

nh dng d liu (data formatting).Chuyn i dnh dng (format exchange).

Nn d liu (data compression).


Layer 7: The Application Layer

Cung cp cc phng tin ngi dng c thtruy cp vo m hnh OSI.Cc giao thc truyn thng ip gia cc chng trnh

ng dng (web, mail).

Cc dch v cho cc ng dng nm ngoi m hnh OSI(Word, Access, SQL Server)


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Ti sao phi phn tng?


No-layered & Layered

Telnet FTP

packetradio

coaxialcable

fiberoptic

Application

TransmissionMedia

HTTP

HTTPTelnet FTP

packetradio

coaxialcable

fiberoptic

Application

TransmissionMedia

Transport& Network

No-layered

Layered


OSI Summary

Physical: binary transmission signals, media, connectors, voltages

Data Link: access to media bits error control, flow control.

physical addressing, net topology.

Network: address and best path path selection, routing, addressing, internetwork.

Transport: end-to-end transmission data transportation, virtual circuit

error detection and recovery, information flow control

Session: interhost communication session management

Presentation: data representation data format, data syntax

Application: network services to applications


TCP/IP Reference Model

M hnh OSI ch mang tnh cht l thuyt, phc vnghin cu v hc tp.

TCP/IP l m hnh p dng cho mng Internet.TCP = Transmission Control Protocol.

IP = Internet Protocol.

TCP, IP l hai giao thc ph bin trong h giao thcTCP/IP.


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TCP/IP Layers & Protocols

Layers

Protocols

Network Access = Host-to-network = Data link + PhysicalNetwork = Internet


i snh OSI v TCP/IP


TCP/IP to OSI

Application

Presentation

Session

Transport

Network

Datalink

Physical

Internet

NetworkAccess

Transport

Application

IP

LAN Packetradio

TCP UDP

Telnet FTP DNS

OSI TCP/IP Protocols


Cisco Certified Network Associate View

UDP

Cng ngh mng


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1.7 - Mng Internet.


1.5. Network Standardization

OSI:

Ch nu ln chc nng ca tng tng.

Khng ch ra ci t cc tng ny nh th no.

hai h thng giao tip c vi nhau th chng cn: c ci t cc chc nng truyn thng chung.

T chc thnh cng mt tp tng.

Hai tng ng mc phi c chung giao thc.

T , cn phi chun ho (standardization)


Cc t chc v chun thng dng

ISO (International Organization for Standardization) http://www.iso.org

CCITT (Commit Consultatif International pour Tlgraphe etTlphone) Khng ban hnh cc chun m ban hnh cc khuyn ngh (X.25).

ANSI (American National Standard Institute)

NIST (National Institute of Standards and Technology)

IEEE (Institute of Electrical and Electronics Engineers)

IAB (Internet Architecture Board).

RFCs (Request For Comments).

IRTF (Internet Research Task Force).

IETF (Internet Engineering Task Force).

ISOC (Internet Society)


Nhm chun IEEE 802 (LAN)


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1.7 - Mng Internet.


1.6. H iu hnh trong mi trng mng

Khng h trmngDOS

Trm lm vicWindows 9x/NT Workstation/2000/XP

MacOS

Linux

My ch qun l mng, cung cp dch v mng.Windows NT/2000/2003 Server

Novel NetWare

Unix, Linux, Sun Solaris









1.7 - Mng Internet.


1.7. Mng Internet

Hng trm triu nt mng c kt ni khp hnh tinh. Hng triu dch v c cung cp (web, mail). Global network of networks.

Mng xng sng (Internet backbone). http://www.hau1.edu.vn/cs/dxha/courses/0405/ipp/


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Trao i dliu gia hai my tnh trong Internet

Tier 1 ISP

Tier 1 ISP

Tier 1 ISP

NAP

Tier-2 ISPTier-2 ISP

Tier-2 ISP Tier-2 ISPTier-2 ISP

localISPlocal

ISPlocalISP

localISP

Tier 3ISP

localISP

localISP

localISP

localISP


Interconnect network OSI view

Application

Presentation

Session

Transport

Network

Datalink

Physical

Application

Presentation

Session

Transport

Network

Datalink

Physical

Network

Datalink

Physical

Physical medium


Internet Data

applicationtransportnetwork

linkphysical


linkphysical


linkphysical


linkphysical

network

linkphysical

data

data


Network Data Flow Review


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Bi tp

Ly v d v s phn tng trong thc t! Lit k cc tng v nhim v c th. Giao tip gia cc tng (giao thc).

Truy cphttp://www.hau1.edu.vn/cs/dxha/courses/0405/comnet/v vit bo co v website ny.Mc ch?Ni dung? Yu cu?

Trnh by cc tng giao thc trong OSI v TCP/IP, nu tnv vai tr ca mt s giao thc. i chiu hai m hnh ny.

Truy cp a ch sau tm hiu thm v Internethttp://www.hau1.edu.vn/cs/dxha/courses/0405/ipp/

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Chapter1 Mang May Tinh Gioi Thieu