Tài Liệu Công Nghệ Internet Tiếng Việt

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Mc lc Cc cng ngh Internet ....................................................................................................... 15

i vi c gi .................................................................................................................... 15

iu kin tin ................................................................................................................. 15

Tng quan v Internet ......................................................................................................... 15

Internet ............................................................................................................................ 15

Qu trnh pht trin ......................................................................................................... 16

Cc li th ...................................................................................................................... 17

Cc bt li ...................................................................................................................... 19

Tng quan v Intranet ......................................................................................................... 21

Intranet ............................................................................................................................ 21

Cc li ch ....................................................................................................................... 22

Giao tip ................................................................................................................... 22

Tit kim thi gian .................................................................................................. 22

S cng tc .............................................................................................................. 22

Nn tng c lp ln nhau (Platform Independency) ....................................... 22

Hiu qu v chi ph ................................................................................................. 23

Nng sut cng vic ............................................................................................... 23

Qun l kinh doanh ................................................................................................. 23

Bo mt .................................................................................................................... 23

Nhng ngi dng ring bit................................................................................ 23

Cp nht lin tc ..................................................................................................... 23

Cc vn ..................................................................................................................... 23

Cc ng dng ................................................................................................................. 24

Cc ng dng lin quan ti cng b ti liu ....................................................... 25

Cc ng dng ngun in t ................................................................................ 25

Cc ng dng thng tin tng tc ....................................................................... 25

H tr cho cc ng dng Internet ........................................................................ 25



S khc nhau gia Internet v Intranet ........................................................................... 26

Tng quan v Extranet ........................................................................................................ 26

Extranet .......................................................................................................................... 26

S thc thi ............................................................................................................... 27

Cc li ch ....................................................................................................................... 28

Cc vn ..................................................................................................................... 29

Hosting ...................................................................................................................... 29

Bo mt .................................................................................................................... 29

Cc vn v truy cp .......................................................................................... 30

Kh nng tng tc b gim st ........................................................................... 30

So snh Extranet v Intranet ........................................................................................... 30

Cc m hnh tham chiu trn Internet ................................................................................. 30

M hnh tham chiu ........................................................................................................ 30

M hnh OSI ................................................................................................................... 31

Tng vt l (Physical Layer) .................................................................................. 31

Tng lin kt d liu ............................................................................................... 32

Tng mng ............................................................................................................... 32

Tng truyn ti ........................................................................................................ 32

Tng phin (Session Layer) .................................................................................. 32

Tng trnh by (Presentation Layer) .................................................................... 32

Tng ng dng ........................................................................................................ 33

M hnh TCP/IP .............................................................................................................. 33

Tng ng dng ........................................................................................................ 34

Tng truyn ti ........................................................................................................ 34

Tng lin mng (Internet) ...................................................................................... 34

Tng Host-to-Network ............................................................................................ 34

H thng tn min (DNS) .................................................................................................... 35

Tng quan ...................................................................................................................... 35

a ch IP ........................................................................................................................ 35



Uniform Resource Locator (URL) .................................................................................... 35

Cc kiu URL........................................................................................................... 35

S khc nhau gia URL quan h v URL tuyt i .......................................... 36

Cu trc H thng tn min ............................................................................................ 37

Cc Tn min .......................................................................................................... 37

Khng gian tn min .............................................................................................. 39

Tn Server ............................................................................................................... 39

Cc khu vc (zones) .............................................................................................. 39

Cch DNS lm vic ........................................................................................................ 41

Cc dch v Internet ............................................................................................................ 41

Cc dch v giao tip ....................................................................................................... 42

Cc dch v thu thp thng tin ......................................................................................... 43

Cc dch v web ............................................................................................................. 43

World Wide Web (WWW) ............................................................................................... 44

Hi ngh truyn hnh (Video Conferencing) ...................................................................... 44

Cc ch ca Hi ngh truyn hnh .................................................................. 44

Kt ni Internet .................................................................................................................... 45

Cc Nh cung cp dch v Internet (ISP) ........................................................................ 45

Cc kiu ISP ............................................................................................................ 45

Cc kiu kt ni .............................................................................................................. 46

Kt ni Dial-up ......................................................................................................... 47

ISDN .......................................................................................................................... 47

DSL ........................................................................................................................... 48

Kt ni truyn hnh cp lin mng ....................................................................... 49

Kt ni Internet dng v tinh nhn to ................................................................ 50

Kt ni Internet khng dy .................................................................................... 51

Cc giao thc Internet ......................................................................................................... 51

Transmission Control Protocol (TCP) .............................................................................. 51

Cc dch v TCP ..................................................................................................... 52



Internet Protocol (IP) ....................................................................................................... 53

User Datagram Protocol (UDP) ...................................................................................... 54

Giao thc truyn ti file (FTP) .......................................................................................... 55

Trivial File Transfer Protocol (TFTP) ................................................................................ 56

S khc nhau gia FTP v TFTP ................................................................................... 57

Telnet.............................................................................................................................. 57

Giao thc truyn ti siu vn bn (HTTP) ....................................................................... 57

Yu cu HTTP ......................................................................................................... 58

Phn hi HTTP ........................................................................................................ 58

Tng quan v Emai ............................................................................................................ 58

Email .............................................................................................................................. 58

a ch th in t .................................................................................................. 58

Cc thnh phn ca thng bo th in t ..................................................................... 59

Header th in t ................................................................................................. 59

Cc li th ...................................................................................................................... 61

ng tin cy ............................................................................................................. 61

Tin li ...................................................................................................................... 61

Tc ....................................................................................................................... 61

R .............................................................................................................................. 61

C th in c......................................................................................................... 61

Tnh ton cu ........................................................................................................... 62

Tnh tng qut ......................................................................................................... 62

Cc nhc im ............................................................................................................. 62

C th gi mo ........................................................................................................ 62

Qu ti ...................................................................................................................... 62

iu hng sai ........................................................................................................ 62

Th rc ..................................................................................................................... 62

Khng c s phn hi ............................................................................................ 62

Cc giao thc trong Email ................................................................................................... 62



SMPTP ........................................................................................................................... 63

Cc lnh SMTP ....................................................................................................... 63

IMAP .............................................................................................................................. 65

Cc lnh IMAP ........................................................................................................ 65

POP................................................................................................................................ 66

Cc lnh POP .......................................................................................................... 67

So snh gia POP v IMAP ........................................................................................... 68

Trnh lm vic ca Email ..................................................................................................... 69

H thng th in t ....................................................................................................... 69

Mailer ........................................................................................................................ 69

Mail Server ............................................................................................................... 69

Mailboxes ................................................................................................................. 69

S lm vic ca th in t ............................................................................................ 70

Cc hot ng trn Email .................................................................................................... 71

To ti khon th in t ................................................................................................ 71

Son v gi th in t .................................................................................................. 73

c th ........................................................................................................................... 74

Th p .......................................................................................................................... 74

Chuyn tip th in t .................................................................................................. 74

Xa th in t ............................................................................................................... 75

Cc tnh nng ca Email ..................................................................................................... 75

nh km ........................................................................................................................ 75

Tp a ch ...................................................................................................................... 75

Cc kiu MIME ............................................................................................................... 76

Quy tc ng x trong Email ................................................................................................ 77

Bo mt th in t ............................................................................................................ 78

Hack th in t ............................................................................................................. 78

Spam ......................................................................................................................... 78

Virus .......................................................................................................................... 78



Phishing .................................................................................................................... 78

Spam th in t v cc Th rc ................................................................................... 79

Chn spam ............................................................................................................... 79

Dn sch v lu gi th in t ...................................................................................... 79

Cc nh cung cp dch v Email ......................................................................................... 80

Tng quan v Website ........................................................................................................ 81

Cc website tnh ............................................................................................................. 81

Cc website ng ........................................................................................................... 82

Cc trang web ng trn Server .......................................................................... 82

Trang web ng trn Client ................................................................................... 82

Cc kiu Website ................................................................................................................ 82

Din n trc tuyn ........................................................................................................ 82

Blog ................................................................................................................................ 83

Cc thut ng lin quan ti Blog.......................................................................... 84

Blog v ch g .................................................................................................... 84

E-commerce (Thng mi in t) ................................................................................ 85

Cc tnh nng .......................................................................................................... 86

Portfolio (H s nng lc) ............................................................................................... 87

Phn loi................................................................................................................... 87

Thit k Website ................................................................................................................. 87

Wireframe ....................................................................................................................... 88

Cc cng c thit k web ................................................................................................ 89

Phn tch trang web ........................................................................................................ 91

Khi ........................................................................................................................... 91

Logo .......................................................................................................................... 91

iu hng .............................................................................................................. 91

Ni dung ................................................................................................................... 91

Chn trang (footer) ................................................................................................. 92

Khong trng trng ................................................................................................. 92



Cc li thit k web ......................................................................................................... 92

Pht trin Web .................................................................................................................... 93

Pht trin web ................................................................................................................. 93

Tin trnh pht trin web .................................................................................................. 94

Cc cng c pht trin web ............................................................................................. 96

Cc tnh nng .......................................................................................................... 96

Cc k nng cn thit ...................................................................................................... 96

y Website ln mng ........................................................................................................ 97

Cc yu cu u tin ...................................................................................................... 97

Phn mm pht trin web...................................................................................... 97

Kt ni mng ............................................................................................................ 97

Web Server .............................................................................................................. 97

ng k URL ...................................................................................................................... 97

Cc ui min ................................................................................................................. 98

ng k tn min ............................................................................................................ 98

Cc t chc qun l ng k tn min ............................................................................ 99

Hosting cc Website ......................................................................................................... 100

ng quan ...................................................................................................................... 100

Cc kiu Hosting ........................................................................................................... 100

Cc Cng ty cung cp dch v Hosting .......................................................................... 101

Ch bo mt Website .................................................................................................. 102

Nghin cu tnh bo mt .............................................................................................. 103

Phn mm c cp nht ................................................................................... 103

SQL Injection ......................................................................................................... 103

Cross Site Scripting (XSS) .................................................................................. 103

Cc thng bo li .................................................................................................. 103

Tnh hiu lc ca d liu ..................................................................................... 103

Mt khu ................................................................................................................. 103

Ti cc file ln ........................................................................................................ 103



SSL .......................................................................................................................... 103

Ti u phng tin tm kim ............................................................................................. 104

SEO l g? .................................................................................................................... 104

Cc loi SEO ......................................................................................................... 104

Cc yu t quan trng ca mt SEO ng quy cch .................................................... 105

Tm kim t kha .................................................................................................. 105

Pht trin ni dung ................................................................................................ 106

Pht trin web ........................................................................................................ 106

Xy dng cc lin kt ........................................................................................... 106

Cc cng c Webmaster ..................................................................................... 106

Nhng g SEO nn thc hin v khng nn thc hin .................................................. 107

Nn thc hin ........................................................................................................ 107

Khng nn thc hin ............................................................................................ 107

To tin t Website ........................................................................................................... 108

Cc phng thc kim tin .......................................................................................... 108

Hin th qung co ................................................................................................ 108

Lin kt tip th ...................................................................................................... 108

Dn d khch hng (Lead Generation) ............................................................. 108

Cho thu th in t (Email Rental) .................................................................. 108

WWW - Tng quan ........................................................................................................... 108

Tng quan .................................................................................................................... 108

Qu trnh pht trin ....................................................................................................... 109

Cu trc WWW ............................................................................................................ 110

B k t v nh danh (Character Set v Identifiers) ...................................... 111

C php .................................................................................................................. 111

Trao i d liu ..................................................................................................... 111

Php phn loi (Taxonomies) ............................................................................. 112

Cc bn th lun (Ontologies) ............................................................................ 112

Cc quy tc ............................................................................................................ 112



Bng chng (Proof) .............................................................................................. 112

Mt m hc ............................................................................................................ 112

Giao thc ngi s dng v cc ng dng .................................................... 112

Hot ng WWW ......................................................................................................... 112

Tng lai ...................................................................................................................... 113

Giao thc ngi s dng .................................................................................... 113

Cng ngh .............................................................................................................. 113

Cu trc .................................................................................................................. 114

Cc trang Web .................................................................................................................. 114

Trang Web.................................................................................................................... 114

Trang web tnh ...................................................................................................... 114

Trang web ng .................................................................................................... 115

Cc ngn ng Scripting ................................................................................................ 115

Client-side Scripting .............................................................................................. 115

Server-side Scripting ............................................................................................ 117

Trnh duyt Web ............................................................................................................... 118

Trnh duyt Web ........................................................................................................... 118

Cu trc .................................................................................................................. 119

Bt u vi Internet Explorer .............................................................................. 120

Truy cp web ......................................................................................................... 122

iu hng ............................................................................................................ 123

Lu trang ................................................................................................................ 124

Lu cc yu t web .............................................................................................. 125

Favourites............................................................................................................... 126



......................................................................................................................................... 129

Web Server ...................................................................................................................... 129

Tng quan .................................................................................................................... 129

Trnh lm vic ............................................................................................................... 129

Cu trc ........................................................................................................................ 130

Concurrent Approach ........................................................................................... 131

a tin trnh ........................................................................................................... 131

a threaded ........................................................................................................... 131

Hn hp .................................................................................................................. 131

Cc v d ...................................................................................................................... 131

Server y nhim (Proxy Server) ........................................................................................ 132

Tng quan .................................................................................................................... 132



Mc ch ca cc Server y nhim ............................................................................... 133

Gim st v lc ...................................................................................................... 133

Ci thin hiu sut ................................................................................................ 133

Transalation ........................................................................................................... 133

Truy cp vo cc dch v di dng n danh .................................................. 134

Bo mt .................................................................................................................. 134

Cc kiu y nhim ........................................................................................................ 134

y nhim chuyn tip ........................................................................................... 134

y nhim m ......................................................................................................... 134

y nhim o chiu .............................................................................................. 134

Cu trc ........................................................................................................................ 135

Giao din ngi s dng y nhim ................................................................... 136

Proxy server listener ............................................................................................. 137

B qun l kt ni ................................................................................................. 137

Qun l b nh n ................................................................................................ 137

Qun l log ............................................................................................................. 137

nh cu hnh ........................................................................................................ 138

Cc phng tin tm kim ................................................................................................ 138

Gii thiu ...................................................................................................................... 138

Cc thnh phn ca phng tin tm kim ................................................................... 139

Web crawler ........................................................................................................... 139

C s d liu ......................................................................................................... 139

Cc giao din tm kim ........................................................................................ 139

Cch phng tin tm kim lm vic ............................................................................. 139

Cu trc ........................................................................................................................ 140

Tin trnh phng tin tm kim .................................................................................... 140

Tin trnh Indexing ................................................................................................ 140

Tin trnh truy vn (Query Process) ................................................................... 141

V d ............................................................................................................................. 141



Tng quan v cng tc trc tuyn ..................................................................................... 142

Chat trc tuyn ............................................................................................................. 142

Quy c Chat ........................................................................................................ 142

Cc dch v Chat trn c s Web ...................................................................... 143

Tin nhn tc thi (IM) .................................................................................................... 144

Internet Relay Chat (IRC) .............................................................................................. 145

Cc lnh IRC ......................................................................................................... 145

Video hi ngh ............................................................................................................... 146

Cc ch ca Video hi ngh ........................................................................... 146

Chia s Video ............................................................................................................... 147

Danh sch gi th trong Email ......................................................................................... 148

Danh sch gi th ........................................................................................................ 148

Cc kiu Danh sch gi th ............................................................................... 148

Cch Danh sch gi th lm vic ................................................................................. 148

Tm kim Danh sch gi th ........................................................................................ 149

ng k Danh sch gi th .......................................................................................... 149

Din n ........................................................................................................................... 150

Usenet (USEr NETwork) .............................................................................................. 150

Phn loi din n ................................................................................................ 150

Cch lm vic ca Usenet ................................................................................... 152

c cc bi vit ..................................................................................................... 153

a mt bi vit ln (post) .................................................................................. 153

Phn hi mt bi vit ............................................................................................ 153

Xa mt bi vit .................................................................................................... 153

Nghi thc mng Usenet ....................................................................................... 153

Danh sch gi th v Din n .................................................................................... 154

o to trc tuyn ............................................................................................................ 155

o to trc tuyn ........................................................................................................ 155

Li ch ..................................................................................................................... 155



Chng ch trc tuyn .................................................................................................... 155

Hi ngh chuyn (Seminar) trc tuyn ...................................................................... 156

Li ch ..................................................................................................................... 156

Webinar ........................................................................................................................ 156

Conferencing ......................................................................................................... 156

Li ch ..................................................................................................................... 156

Mng x hi ...................................................................................................................... 157

Gii thiu ...................................................................................................................... 157

Cc dch v Mng x hi hin c ....................................................................... 157

Tin ch ca mng x hi .............................................................................................. 158

Tip th trc tuyn ................................................................................................. 158

Cng vic trc tuyn ............................................................................................ 158

Tin tc trc tuyn .................................................................................................. 158

Chat ......................................................................................................................... 159

Chia s hnh nh, Audio, Video .......................................................................... 159

Bo mt trn Internet ........................................................................................................ 159

Gii thiu ...................................................................................................................... 159

Internet Security Protocol (IPSec) ...................................................................... 159

Secure Socket Layer (SSL) ................................................................................. 159

Cc nguy c ................................................................................................................. 159

Phishing th in t ...................................................................................................... 160

Nhng g trong mt Phishing email? ................................................................. 160

Mt m ha d liu ........................................................................................................... 161

Gii thiu ...................................................................................................................... 161

Cc kiu Mt m ha ........................................................................................... 161

Hashing ........................................................................................................................ 162

Cc thut ton chc nng Hash ......................................................................... 162

Ch k k thut s ............................................................................................................ 163

Ch k k thut s ........................................................................................................ 163



Cc ng dng ............................................................................................................... 163

S xc nhn .......................................................................................................... 163

Tnh nguyn vn ................................................................................................... 164

Khng th ph nhn ............................................................................................. 164

Tng la bo mt .......................................................................................................... 164

HTML ............................................................................................................................... 165

Gii thiu ...................................................................................................................... 165

Cc phin bn HTML ........................................................................................... 165

Cc th HTML .............................................................................................................. 166

Cc th c bn ............................................................................................................. 166

Cc th nh dng ......................................................................................................... 167

Cc th bng ................................................................................................................ 168

Cc th danh sch ........................................................................................................ 168

Cc Frame.................................................................................................................... 169

Cc form ....................................................................................................................... 170

CSS .................................................................................................................................. 170

Gii thiu ...................................................................................................................... 170

Cc quy tc CSS ................................................................................................... 170

Nhng CSS vo trong HTML ........................................................................................ 171

Inline Style Sheets ................................................................................................ 171

Embedded Style Sheets ...................................................................................... 172

External Style Sheets ........................................................................................... 172

Imported Style Sheets .......................................................................................... 173

JavaScript ......................................................................................................................... 174

Gii thiu ...................................................................................................................... 174

Cc lnh trong JavaScript ............................................................................................. 175

Comment trong JavaScript ........................................................................................... 175

PHP .................................................................................................................................. 176

Gii thiu ...................................................................................................................... 176



S dng PHP ............................................................................................................... 177

Cc nt c trng ......................................................................................................... 177

"Hello World" Script trong PHP: ..................................................................................... 177

Ti liu tham kho v Cng ngh Internet ......................................................................... 178

Cc ng link hu ch v Cng ngh Internet............................................................. 178

Cc cng ngh Internet Internet l s kt ni gia cc mng vi nhau. Trong mng ny, mi my tnh c nhn ra bi

mt a ch duy nht trn ton cu m c bit n vi tn gi l a ch IP. Mt DNS ca mt

my tnh c bit c s dng cung cp tn cho a ch IP m t ngi s dng c th

xc nh v tr ca mt my tnh bi mt tn.

V d, mt DNS Server s phn gii mt tn http://mp3.zing.vn thnh mt a ch IP c th xc

nhn mt cch duy nht my tnh m trn webside ny c t v tr.

Lot bi hng dn ca chng ti da trn ngun ti liu ca: Tutorialspoint

i vi c gi Phn hng dn ny khng nhng c chun b cho nhng sinh vin cng nh cc nh lp trnh

chuyn nghip m cn d hiu vi nhng ngi khc cung cp s hiu bit cng nh xy dng

cu trc kin thc v cc cng ngh Internet.

iu kin tin Trc khi thc hin theo chng trnh hc ca phn hng dn ny, bn nn c mt kin thc c

bn v cc my tnh, m s gip bn trong vic tip thu nhanh v d dng hn vi phn hng

dn ca chng ti.

Tng quan v Internet Internet Internet c nh ngha nh l mt ng truyn thng tin cao tc, truy cp thng tin qua cc

trang web. Ngoi ra, n cng c th c nh ngha vi nhiu cch khc nhau sau:



Internet l mt h thng cc mng my tnh c lin kt vi nhau tri rng ton cu.

Internet s dng Giao thc Internet tiu chun (TCP/IP).

Mi my tnh trong Internet c xc nh bi mt a ch IP duy nht.

a ch IP l mt b cc s duy nht (nh 110.22.33.114) m xc nh mt v tr ca my

tnh.

Mt DNS Server c bit c s dng cung cp tn cho cc a ch IP t ngi

s dng c th xc nh v tr ca mt my tnh bng mt tn.

V d, mt DNS Server s phn gii mt tn http://vnexpress.net thnh mt a ch IP c

th xc nh mt cch duy nht my tnh m trn trang web ny c t.

Internet l c th truy cp bi tt c mi ngi s dng trn ton th gii.

Qu trnh pht trin Khi nim v Internet c a ra ln u tin vo nm 1969 v cho n nay tri qua nhiu s

thay i v cng ngh cng nh C s cu trc h tng. Nhng thay i ny l:



Khi ngun ca khi nim Internet bt ngun t Advanced Research Project Agency

Network (ARPANET) - C quan d n nghin cu cao cp.

ARPANET c pht trin bi B quc phng Hoa k.

Mc ch c bn ca ARPANET l cung cp s trao i thng tin gia cc phng ban

ca chnh ph.

Lc u, ch c 4 node, thng c gi l Host.

Vo nm 1972, ARPANET tri rng ton cu vi 23 trm c t v tr ti cc quc gia

khc nhau v v th c bit n nh l Internet.

Cng thi gian, vi pht minh ca cc cng ngh mi nh cc giao thc TCP/IP, DNS,

WWW, cc trnh duyt, cc ngn ng lp trnh, . Internet cung cp mt trung gian

qung b v truy cp thng tin thng qua web.

Cc li th Internet c mt trong mi kha cnh ca i sng, tt c nhng kha cnh c th m chng ta ngh

v. Ti y, chng ta s tho lun mt s li th ca Internet.



Internet cho php chng ta giao tip vi mi ngi m ti v tr rt xa. C mt s ng dng

c sn trn mng m s dng Internet nh l mt trung gian cho s giao tip. Bn c th

tm thy cc trang mng x hi nh:

o Facebook

o Twitter

o Yahoo

o Google+

o Flickr

o Orkut

Bn c th lt qua bt k thng tin no thng qua Internet. Thng tin lin quan n nhiu

ch khc nhau v a dng nh Cng ngh, sc khe v khoa hc, x hi, a l, lch s,

cng ngh thng tin, cc sn phm, Cc thng tin ny c th c truy cp bi mt

cng c tm kim.



Bn cnh vic cung cp vic giao tip v trao i thng tin, Internet cng phc v nh l

mt trung gian gii tr. Di y l cc ch a dng cho gii tr thng qua Internet.

o TV trc tuyn

o Tr chi trc tuyn

o Cc bi ht

o Cc Video

o Cc ng dng mng x hi.

Internet cn cung cp cho chng ta nhiu dch v nh:

o Giao dch ngn hng trc tuyn

o Mi gii hn nhn trc tuyn

o Mua hng trc tuyn

o t v trc tuyn

o Thanh ton trc tuyn

o Chia s d liu

o Th in t.

Internet cung cp khi nim Thng mi in t m cho php cc giao dch kinh t c

thc hin thng qua cc h thng in t.

Cc bt li Mc d, Internet chng minh ngun sc mnh v thng tin ca n trong hu ht cc trng, th

vn cn tn ti nhiu s bt cp nh sau:



Lun lun c nguy c l ra cc thng tin c nhn quan trng nh tn, a ch, m s th tn

dng . V th, bn nn rt cn thn trong khi chia s thng tin. Bn ch nn s dng th

tn dng ca mnh cc trang c cho l tin cy.

Nhc im khc l Spam (vit tt ca Stupid Pointless Annoying Messages). Spam lin

quan ti vic nhn c cc th in t m khng mong mun. Nhng th in t ny

khng phc v mc ch no v l nguyn nhn gy tc nghn ton h thng.

Virus c th d dng tri rng ton b cc my tnh c kt ni ti Internet. Nhng cuc

tn cng ca virut c th lm h thng sp hoc cc d liu quan trng ca bn c th

b xa.

Mt nguy c ln nht trn Internet l cc trang khiu dm. C nhiu cc trang khiu dm

m c th c tm thy, lm cho nhng a tr ca bn khi s dng Internet c th truy

cp v b nh hng trc tip ti cuc sng tm l ca chng.

C nhiu trang m khng cung cp cc thng tin ng tin cy. iu ny gy ra s nhn

thc v hiu sai v mt ci g ca nhiu ngi.



Tng quan v Intranet Intranet Intranet c nh ngha nh l mng ni b ca cc my tnh trong mt t chc vi Server v

tng la ring ca n. Ngoi ra, chng ta c th nh ngha Intranet nh sau:

Intranet l mt h thng m trong nhiu PC c kt ni vi nhau. Cc PC trong mng

ni b khng c sn vi th gii bn ngoi ca mng .

Thng th mi cng ty hoc t chc c mng ni b ring v mi thnh vin/nhn vin ca

cng ty c th truy cp vo cc my tnh trong mng ni b .

Mi my tnh trong Internet c nhn din bi mt a ch IP ring duy nht.

Mi my tnh trong Intranet cng c nhn din bi mt a ch IP, m l duy nht trong

cc my tnh ca mng .



Cc li ch Intranet l mt h thng mng hiu qu v thch hp cho bt k t chc no. N th hin li ch

ca n trong cc kha cnh nh s cng tc, hiu qu v chi ph, bo mt, nng sut v nhiu th

khc na.

Giao tip

Intranet cung cp phng thc giao tip (trao i thng tin) d dng v hiu qu trong mt t chc.

Mi nhn vin c th giao tip vi nhau bi s dng cc cng c nh ni chuyn trc tuyn, th

in t hoc cc blog.

Tit kim thi gian

Thng tin trn Intranet c chia s theo phng thc thi gian thc (real time).

S cng tc

Thng tin c phn phi trong cc thnh vin theo nhu cu v n c th c truy cp bi nhng

ngi s dng c trao quyn, kt qu l nng cao hiu sut cng vic trong team.

Nn tng c lp ln nhau (Platform Independency)

Intranet c th kt ni cc my tnh v cc thit b khc vi cu trc khc nhau.



Hiu qu v chi ph

Cc thnh vin c th thy d liu v cc ti liu khc bi s dng cc trnh duyt thay v phi in

v phn phi cc bn sao cho cc thnh vin trong nhm, iu ny lm gim chi ph.

Nng sut cng vic

D liu lun c sn mi lc v c th c truy cp bi s dng mng ni b cng ty. iu ny

gip cho cc nhn vin lm vic nhanh hn.

Qun l kinh doanh

N cng c th trin khai mt s ng dng m h tr cc hot ng qun l kinh doanh.

Bo mt

Khi thng tin c chia s trn Intranet, n ch c th c truy cp trong mt t chc. V th, s

khng c nhiu nguy c b nh cp thng tin.

Nhng ngi dng ring bit

Intranet c thit lp vi mc tiu ch dnh cho nhng ngi dng c th, ring bit trogn mt t

chc, v th, c th bit c chnh xc ai ang s dng v tng tc.

Cp nht lin tc

Bt c thay i no lin quan n thng tin c phn nh ngay lp tc ti tt c nhng ngi s

dng.

Cc vn Ngoi cc li ch trn ca Intranet, vn cn tn ti mt s vn . Nhng vn ny c ch

trong gin sau:



Cc ng dng Cc ng dng Intranet l ging nh cc ng dng Internet. Cc ng dng mng ni b cng c

truy cp thng qua mt trnh duyt web. S khc nhau ch c ch l, cc ng dng Intranet nm

trong Server ni b trong khi cc ng dng Internet nm trong Server t xa. Ti y, chng ta

thao lun v mt s ng dng sau:



Cc ng dng lin quan ti cng b ti liu

Cc ng dng ny cho php cng b cc ti liu nh cc sch hng dn, phn mm hng dn,

li nhun, m khng cn s dng giy t.

Cc ng dng ngun in t

N cung cp cc ng dng ngun in t nh cc ng dng phn mm, mu v cng c, c

chia s trong mng.

Cc ng dng thng tin tng tc

Nh trn Internet, chng ta c th in t v ni chuyn trc tuyn cng l cc ng dng cho

Intranet, m cung cp mt phng tin thng tin tng tc cho cc thnh vin.

H tr cho cc ng dng Internet

Intranet cung cp mt mi trng trin khai v th nghim cc ng dng trc khi t chng

trn Internet.



S khc nhau gia Internet v Intranet Ngoi mt s im ging nhau trn, cn c mt s im khc bit gia chng. Di y lit k mt

s im khc nhau gia Internet v Intranet:

Intranet Internet

Mng ni b Mng ton cu

Khng c quyn truy cp ti Intranet C quyn truy cp ti Internet

t hn R hn

An ton hn t an ton hn

ng tin cy hn t tin cy hn

Tng quan v Extranet Extranet Extranet lin quan ti lin kt mng trong mt t chc, s dng Internet kt ni vi bn ngoi

trong phng thc c kim sot. N gip kt ni doanh nghip vi khc hng v cc nh cung

cp ca n v v th cho php lm vic trong mt phng thc c s cng tc.



S thc thi

Extranet c thc thi nh l cc Mng ni b o (VPN) bi v n s dng Internet kt ni ti t

chc thuc on th v n cng l mt nguy c ti bo mt thng tin. VPN cung cp mt mng an

ton trong Cu trc h tng mng cng cng.

Cc im chnh:

Gi d liu c ng gi ti bin gii ca cc mng trong cc thit b tuyn IPSEC.



N s dng mt kha mt m ng gi cc gi d liu v cc a ch IP.

Gi d liu ch c gii m bi cc thit b tuyn IPSEC hoc cc Server.

Thng bo c gi qua VPN thng quan cc Tunnel ca VPN v tin trnh ny c bit

nh l tunneling.

VPN s dng Giao thc Internet Protocol Security Architecture (IPSEC) cung cp cc s

truyn ti thng tin c bo mt bi vic thm vo mt Tng bo mt ti giao thc TCP/IP. Tng

ny c to bi vic ng gi gi d liu IP ti mt gi d liu IP mi nh c ch trong gin

di:

Cc li ch Extranet chng minh n nh l mt m hnh thnh cng cho tt c cc doanh nghip d ln hay

nh. Di y l mt s cc li th ca Extranet cung cp cho cc nhn vin, cc nh cung cp,

cc i tc kinh doanh v khch hng:



Cc vn Ngoi nhng li th trn, Extranet cng cn tn ti mt s nhc im. Nhng vn ny c

tho lun di y:

Hosting

Hosting l khng gian trn b mt Server dng t cc dch v Internet. Ti ni cc trang

Extranet s c gi, v d: ai s Host cc trang Extranet. Trong bi cnh ny, c hai la chn:

Host n trn Server ring ca bn

Host n vi mt ISP theo cch tng t nh cc trang web.

Nhng Hosting cc trang Extranet trn Server ring ca bn yu cu mt bng thng kt ni

Internet cao m gi c th rt t.

Bo mt

Tng la (firewall) bo mt c yu cu nu bn Host cc trang Extranet trn Server ring ca

ban m kt qu l mt k thut bo mt phc tp v lm tng lng ti.



Cc vn v truy cp

Thng tin c th khng c truy cp m khng s dng kt ni Internet. Tuy nhin, thng tin c

th c truy cp trong Intranet m khng kt ni Internet.

Kh nng tng tc b gim st

N gim kh nng tng tc trc tip trong doanh nghip m kt qu l s thiu giao tip vi khc

hng, i tc v cc nh cung cp.

So snh Extranet v Intranet Bng di y ch s khc nhau gia Extranet v Internet:

Extranet Intranet

Mng Extranet c th c truy cp t bn

ngoi.

Mng Intranet khng th

c truy cp t bn ngoi.

Extranet l s m rng ca mng Intranet

ca cng ty.

Ch gii hn cho nhng ngi

s dng ca mt cng ty.

Gii hn vi cc giao tip vi bn ngoi ch

vi khch hng, cc nh cung cp v i tc.

Ch dnh cho s giao tip cho

trong mt cng ty.

Cc m hnh tham chiu trn Internet M hnh tham chiu M hnh tham chiu cung cp mt phng thc tiu chun ha m c th chp nhn trn ton th

gii. T khi con ngi s dng mng my tnh thng qua mt phm vi vt l rng v cc thit b

mng ca h c th c cu trc hn hp. cung cp s trao i thng tin gia cc thit b hn

hp , chng ta cn mt m hnh tiu chun ha, v d: mt m hnh tham chiu, m s cung cp

cho chng ta cch cc thit b c th giao tip m khng quan tm n cu trc ca n.

Chng ta c hai m hnh tham chiu nh M hnh OSI v M hnh TCP/IP, tuy nhin, trong khi M

hnh OSI l mt m hnh gi thuyt th M hnh TCP/IP l m hnh hon ton thc tin.



M hnh OSI OSI l vit tt ca Open System Interface Giao din h thng m. M hnh ny c pht

trin bi T chc tiu chun quc t ISO v v th n cng cn c bit nh l M hnh ISO-OSI.

M hnh OSI gm c 7 Tng nh gin di y. Mi Tng c mt chc nng ring bit, tuy

nhin mi Tng cung cp cc dch v ti Tng trn ca n.

Tng vt l (Physical Layer)

Tng vt l chu trch nhim cho cc hot ng sau:

Kch hot, duy tr v tt cc kt ni vt l.

Xc nh mc in p v t l d liu cn thit cho s truyn ti.

Chuyn i cc bit d liu thnh cc tn hiu in t.

Quyt nh c hay khng kt ni l simlex, half duplex hoc full duplex.



Tng lin kt d liu

Tng ny thc hin cc chc nng nh sau:

Thc hin ng b ha v kim sot li cho thng tin m c truyn ti qua Tng vt l.

Kh nng pht hin li v thm cc bt pht hin li ti d liu m c truyn ti.

Tng mng

Di y l cc chc nng ca Tng mng:

nh tuyn cc tn hiu thng qua cc knh khc nhau ti u nhn khc.

Hot ng nh l b iu khin mng bi vic quyt nh d liu s c i theo tuyn

no.

phn chia cc thng bo sp truyn ti ra thnh cc gi d liu v tp hp cc gi d

liu thnh cc thng bo cho cc Tng cao hn.

Tng truyn ti

Tng ny thc hin cc chc nng sau:

N quyt nh nu truyn ti d liu nn din ra trn cc ng truyn song song hoc

ng truyn n.

N thc hin cng vic kt hp (dn) hoc chia nh d liu.

N phn d liu thnh cc n v nh hn m chng c th c kim sot hiu qu

hn bi Tng mng.

Tng truyn ti bo m vic truyn ti d liu t u ny ti u khc.

Tng phin (Session Layer)


Qun l cc thng bo v ng b ha cc trao i thng tin gia hai ng dng khc nhau.

N iu khin s ng nhp hoc ng thot, s nhn din ngi s dng, qun l phin.

Tng trnh by (Presentation Layer)




Tng ny bo m rng thng tin c phn phi trong mt mu m h thng nhn s hiu

v s dng n.

Tng ng dng

Tng ng dng thc hin cc chc nng sau:

N cung cp cc dch v khc nhau nh thao tc thng tin theo nhiu cch, truyn ti li

cc file ca thng tin, phn phi cc kt qu, .

Cc chc nng nh ng nhp, hoc kim tra mt khu c thc hin bi Tng ny.

M hnh TCP/IP M hnh ny l mt m hnh thc tin v c s dng trong Internet. TCP/IP l vit tt ca

Transmission Control Protocol Giao thc kim sot truyn ti v Internet Protocol Giao thc

lin mng.

M hnh ny kt ni hai Tng (Tng vt l v Tng lin kt d liu) vo trong mt Tng, v d:

Tng Host-to-Network. Gin di y ch cc Tng khc nhau ca M hnh TCP/IP:



Tng ng dng

Tng ny l ging nh trong m hnh OSI v thc hin cc chc nng sau:

N cung cp cc dch v khc nhau nh thao tc thng tin theo nhiu cch, truyn ti li

cc file thng tin, phn phi cc kt qu, .

Cc chc nng nh ng nhp hoc kim tra mt khu cng c thc hin bi Tng ng

dng.

Cc giao thc c s dng trong lp ny l: TELNET, FTP, SMTP, DN, HTTP, NNTP.

Tng truyn ti

N thc hin cc chc nng tng t nh Tng truyn ti trong M hnh OSI. Di y l cc

im chnh lin quan n Tng truyn ti:

N s dng giao thc TCP v UDP cho truyn ti end-to-end.

TCP l giao thc ng tin cy v c iu hng kt ni.

TCP cng kim sot dng d liu.

UDP th khng ng tin cy v mt giao thc t kt ni hn cng khng thc hin chc

nng kim sot dng d liu.

Cc giao thc c s dng trong Tng ny l: TCP/IP v UDP.

Tng lin mng (Internet)

Chc nng ca Tng ny l cho php Host chn cc gi d liu vo trong mng v sau lm cho

chng truyn i mt cch c lp ti ch n. Tuy nhin, th t nhn cc gi d liu c th khc

nhau vi dy lin tc m chng c gi.

Cc giao thc c s dng trong Tng ny l: IP.

Tng Host-to-Network

y l Tng thp nht trong M hnh TCP/IP. Host phi kt ni vi mng bi s dng mt s giao

thc, m n c th gi cc gi IP qua n. Giao thc ny l a dng t Host ti Host v mng

ti mng.

Cc giao thc c s dng trong Tng ny l: ARPANET, SATNET, LAN, gi d liu v tuyn

(packets radio).



H thng tn min (DNS) Tng quan Khi DNS khng tn ti, bn phi ti v mt Host file cha tn Host v a ch IP tng ng. Nhng

vi s lng Host ca lin mng tng ln, kch c ca tp Host cng tng. Kt qu l s trao i

c tng ln trong qu trnh ti xung file ny. gii quyt vn ny, h thng DNS c gii

thiu.

H thng tn min (DNS) gip phn gii tn Host thnh mt a ch. N s dng gin t tn c

th bc v d liu c phn phi ca cc a ch IP v cc tn lin kt.

a ch IP a ch IP l mt a ch logic duy nht c ch nh ti mt thit b thng qua mng. Mt a ch IP

trnh by cc thuc tnh sau:

a ch IP l a ch duy nht c ch nh ti mi Host c trn Internet.

a ch IP l 32 bit (4 Byte) di.

a ch IP ca hai thnh phn: Thnh phn mng v Thnh phn Host.

Mi 4 Byte c biu din bi mt s t 0 n 255, c lp bi du chm. V d:

137.170.4.124.

a ch IP l mt s 32 bit trong khi cc tn min l d dng nh. V d, khi chng ta nhp mt

a ch email chng ta lun lun nhp mt dy k hiu nh l vnexpress.net

Uniform Resource Locator (URL) URL lin quan ti mt a ch web m xc nh duy nht mt ti liu thng qua Internet.

Ti liu ny c th l mt trang web, nh, Audio, Video hoc bt c th g c trn web.

V d, www.tutorialspoint.com/Internet_technology/index.jspl l mt a ch URL ti trang index.jspl

m c lu trn Server trang tutorialspoint di th mc Internet_technology.

Cc kiu URL

C hai kiu URL l:

1. URL tuyt i



2. URL quan h.

URL TUYT I

L mt a ch y ca mt ngun trn trang web. a ch y ny bao gm giao thc c

s dng, tn Server, tn ng truyn, v tn file.

V d: http:// www.vietjack.com/internet_technologies/index.jsp. y::

http l giao thc.

vietjack.com l tn Server.

index.jsp l tn file.

Phn giao thc ni cho trnh duyt web bit cch kim sot file. Tng t, chng ta c mt s giao

thc khc m cng c th c s dng to URL l:

FTP

https

Gopher

mailto

news

URL QUAN H

URL quan h l mt a ch cc b ca mt trang web. Khng ging vi URL tuyt i, phn giao

thc v phn Server c b quan trong URL quan h.

Cc URL quan h c s dng cho cc lin kt ni b, v d: to cc lin kt ti file m l mt

phn ca cng website m trn bn ang t lin kt.

V d, kt ni mt nh trn

../internet_technologies/Internet_technology/Internet_reference_models, chng ta c th s dng

URL quan h m c th nhn mu ging nh /Internet_technologies/Internet-osi_model.jpg.

S khc nhau gia URL quan h v URL tuyt i

URL tuyt i URL quan h



c s dng lin kt cc trang

web trn cc website khc nhau

c s dng lin kt ti cc

trang trong cng mt website

Kh qun l D dng qun l

Thay i khi tn Server hoc tn th

mc thay i

Gi nguyn ngay c khi chng ta thay

i tn Server hoc tn th mc

Tn thi gian truy cp Thi gian truy cp nhanh hn so vi

URL tuyt i

Cu trc H thng tn min H thng tn min bao gm cc Tn min, Khng gian tn min, Tn Server m c miu t

di y:

Cc Tn min

Cc tn min l mt chui k hiu lin quan ti mt a ch IP. C mt s tn min c sn; mt s

chng dng chung nh com, edu, gov, net, , trong khi cn mt s tn min cp quc

gia nh au, in, za, us, .

Bng di y ch cc tn min Chung c s dng mc cao (top-level).

Tn min ngha

Com Kinh doanh thng mi

Edu Gio dc

Gov C quan chnh ph US

Int i tng mang tm quc t

Mil Qun i US



Net T chc mng

Org T chc khng v mc tiu li nhun

Bng di y ch cc tn min Quc gia c s dng mc cao.

Tn min ngha

au c

in n

cl Chi L

fr Php

us Hoa K

za Nam Phi

uk Anh

jp Nht Bn

es Ty Ba Nha

de c

ca Canada

ee Estonia

hk Hng Kng



Khng gian tn min

Khng gian tn min ni n h thng c cp bc trong cu trc tn Internet. H thng c cp bc

ny c nhiu mc (t 1 n 127), mt mt gc ti trn u. Gin sau y ch h thng c cp

bc khng gian tn min.

Trong gin trn, mi cy ph biu din mt min. Mi min c th c chia ra thnh cc min

ph v nhng min ph ny c th c tip tc chia ra thnh cc min ph khc, v qu trnh c

th tip tc din ra.

Tn Server

Tn Server cha c s d liu DNS. C s d liu ny cha nhiu tn a dng v cc a ch IP

tng ng ca n. T khi n khng th dng cho mt Server n duy tr c s d liu ton b,

v th, thng tin c phn phi trong nhiu DNS Server.

H thng c cp bc ca Server l tng t nh h thng c cp bc ca cc tn.

Khng gian tn ton b c phn chia thnh cc khu vc.

Cc khu vc (zones)

Khu vc l mt tp hp ca cc trm node (cc min ph) di min chnh. Server duy tr mt

c s d liu c gi l tp khu vc cho mi khu vc.



Nu min khng c phn chia thnh cc min ph, th khi min v khu vc cng ni n mt

th.

Thng tin v cc trm trong min ph c lu gia trong cc Server ti cc mc thp nht, tuy

nhin, Server ban u gi cc thng tin tham chiu ti cc mc thp nht ny.

KIU CA CC TN MIN

Di y l 3 loi Tn Server m qun l H thng tn min:

1. Root Server (Server gc)

2. Primary Server (Server s cp)

3. Secondary Server (Server th cp)

ROOT SERVER

L Server cp trn cng m cha ton b cy DNS. N khng cha thng tin v cc min

nhng y quyn ti cc Server khc.

PRIMARY SERVERS

Lu tr mt file v khu vc ca n. N c thm quyn to, duy tr, v cp nht tp khu vc.



SECONDARY SERVER

Truyn ti thng tin y v mt khu vc t Server khc m c th l s cp hoc th cp.

Server th cp khng c thm quyn to hoc cp nht mt tp khu vc.

Cch DNS lm vic DNS dch tn min thnh a ch IP mt cch t ng. Di y lit k cc bc v tin trnh x l

tn min ca DNS.

1. Khi chng ta nhp www.tutorialspoint.com vo trnh duyt, n hi DNS Server ni b cho

a ch IP ca n.

y DNS ni b l ti u ISP.

2. Khi DNS ni b khng tm thy a ch IP ca tn min yu cu, n chuyn tip yu cu

ti DNS Server gc (root) v sau li yu cu v a ch IP ca n.

3. DNS Server gc phn hi vi s y nhim rng Ti khng bit v a ch IP ca

www.tutorialspoint.com nhng bit v a ch IP ca DNS Server.

4. DNS n b sau hi com DNS Server cng mt cu hi nh th.

5. Server com DNS phn hi ging nh trn l Ti khng bit a ch IP ca

www.tutorialspoint.com nhng bit a ch ca tutorialspoint.com.

6. Sau , DNS ni b hi DNS Server tutorialspoint.com cng cu hi .

7. Sau , DNS Server tutorialspoint.com phn hi vi a ch IP ca www.tutorialspoint.com.

8. By gi, DNS ni b gi a ch IP ca www.tutorialspoint.com ti my tnh m gi yu cu.

Cc dch v Internet Cc dch v Internet cho php chng ta truy cp vo s lng ln thng tin nh vn bn, ha,

m thanh v phn mm qua Internet. Gin di y ch 4 kiu dch v Internet khc nhau:



Cc dch v giao tip C rt nhiu dch v giao tip (trao i thng tin) a dng m cung cp s trao i ca thng tin vi

cc c nhn hoc cc nhm. Bng di y ch cc gii thiu ngn gn v cc dch v ny:

STT Miu t dch v

1 Th in t

c s dng gi thng bo in t qua Internet.

2

Telnet

c s dng ng nhp vo cc my t xa m c kt ni vi

Internet.

3

Nhm thng tin (Newsgroup)

Cung cp mt din n cho mi ngi bn lun v cc ch cng

quan tm chung.

4

IRC Chat chuyn tip Internet

Cho php mi ngi t khp ni trn th gii giao tip trc tip vi

nhau.

5

Danh sch mail

c s dng t chc nhm ngi s dng chia s thng tin

chung thng qua th in t.



6

in thoi Internet (VoIP)

Cho php ngi s dng Internet ni chuyn thng qua Internet ti bt

k PC no c trang b nhn triu hi.

7

Tin nhc nhanh

Dch v cho php hai ngi tr ln ni chuyn trc tuyn vi nhau. V

d: Yahoo messenger, MSN messenger.

Cc dch v thu thp thng tin C mt s dch v thu thp thng tin cho php d dng truy cp ti thng tin c trn Internet. Bng

di y l cc gii thiu ngn gn v cc dch v ny:

STT Miu t dch v

1 Giao thc truyn ti file (FTP)

Cho php ngi s dng truyn ti cc file.

2

Archie

N l c s d liu c cp nht ca cc FTP site cng cng v ni

dung ca chng. N gip tm kim mt file da vo tn ca n.

3

Gopher

c s dng tm kin, thu nhn v hin th cc ti liu trn cc site

t xa.

4

Very Easy Rodent Oriented Netwide Index to Computer Achieved

(VERONICA)

L Gopher da trn c s ngun. N cho php truy cp ti thng tin

ngun c lu gi trn cc Server Gopher.

Cc dch v web Cc dch v web cho php trao i thng tin gia cc ng dng trn web. S dng cc dch v

web, cc ng dng c th d dng tng tc vi nhau.



Cc dch v web c cung cp bi s dng khi nim Utility Computing in ton theo nhu

cu.

World Wide Web (WWW) WWW cng c bit n nh l W3. N cung cp mt cch truy cp cc ti liu dn tri qua

mt s Server thng qua Internet. Nhng ti liu ny c th cha vn bn, ha, Audio, Video v

siu lin kt. Cc siu lin kt cho php ngi s dng iu hng gia cc ti liu.

Hi ngh truyn hnh (Video Conferencing) Hi ngh truyn hnh l mt phng thc ca giao tip Video hai chiu v truyn ti Audio vi s

gip ca cc cng ngh vin thng.

Cc ch ca Hi ngh truyn hnh

POINT-TO-POINT

Ch ny ch kt ni hai v tr.

MULTI-POINT

Ch ny kt ni nhiu hn hai v tr thng qua n v iu khin a im - Multi-point

Control Unit (MCU).



Kt ni Internet Ti trong chng ny, chng ta s tho lun v cch kt ni ti Internet, v d cc nh cung cp

dch v Internet, cc yu cu phn mm v phn cng, nh cu hnh kt ni Internet, .

Cc Nh cung cp dch v Internet (ISP) Internet Service Provider (ISP) l mt cng ty cung cp s truy cp ti Internet. H cung cp

nhiu dch v a dng:

Truy cp Internet (Internet access)

ng k tn min

Truy cp Dial-up

Truy cp cc tuyn c cho thu.

Cc kiu ISP

Theo mt cch i khi, cc ISP c th c chia thnh 6 loi nh gin bn di:



CC NH CUNG CP DCH V TRUY CP

H cung cp s truy cp ti Internet thng qua cc ng dy in thoi, cp wi-fi hoc cp

quang.

CC NH CUNG CP DCH V HM TH (MAILBOX)

H cung cp cc dch v Hosting hm th.

CC NH CUNG CP DCH V HOSTING

H cung cp cc dch v th in t, v cc dch v Hosting khc nh cc thit b o, my,

CC NH CUNG CP DCH V INTERNET O

H cung cp cc dch v truy cp Internet thng qua cc dch v ISP khc.

CC NH CUNG CP DCH V INTERNET MIN PH

H khng nh ph i vi cc dch v Internet.

Cc kiu kt ni C mt s cch kt ni ti Internet. Di y l mt s kiu kt ni c sn:

1. Kt ni Dial-up

2. ISDN

3. DSL

4. Cc kt ni truyn hnh cp lin mng



5. Cc kt ni Internet dng v tinh nhn to

6. Cc kt ni khng dy

Kt ni Dial-up

Loi Kt ni ny s dng ng dy in thoi kt ni PC ti Internet. N yu cu mt modem

(b iu gii) thit lp kt ni dial-up. Modem ny lm vic nh l mt giao din gia PC v

ng dy in thoi.

Cng c mt chng trnh giao tip m ch dn modem to mt cuc gi ti s c th c cung

cp bi mt ISP.

Kt ni Dial-up s dng mt trong cc giao thc sau:

1. Giao thc n tuyn (SLIP)

2. Giao thc im ti im (PPP)

S di y ch s truy cp Internet bi s dng modem:

ISDN

ISDN L vit tt ca Integrated Services Digital Network Mng s tch hp a dch v. N

thit lp kt ni bi s dng cc ng dy in thoi m mang cc tn hiu k thut s thay v cc

tn hiu analog.

C hai k thut phn phi cc dch v ISDN:

1. BRI Giao din tc c bn



2. PRI Giao din tc s cp

Cc im chnh:

BRI ISDN bao gm 3 knh ring bit trn mt ng ISDN n: knh t1o64kbps B (Bear)

v mt knh 16kbps D (Delta hoc D liu).

PRI ISDN bao gm 23 knh B v mt knh D vi cng dung lng hot ng l 64kbps, to

ra mt tc truyn ti ton b l 1.54Mbps.

S di y ch vic truy cp Internet bi s dng kt ni ISDN:

DSL

DSL l vit tt ca Digital Subscriber Line ng dy thu bao dng s. N l mt mu ca kt

ni broadband khi n cung cp kt ni qua cc ng dy in thoi.

Di y l mt s phin bn ca cng ngh DSL c sn ngy nay:

1. DSL khng i xng (ADSL)

2. DSL i xng (SDSL)

3. DSL tc bit cao (HDSL)

4. DSL tc thch nghi (RDSL)

5. DSL tc bit rt cao (VDSL)



6. ISDN DSL (IDSL)

Tt c nhng cng ngh c cp trn khc nhau trong tc ti ln v ti v, tc truyn

ti bit v cp ca dch v.

S sau ch cch chng ta c th kt ni Internet vi cng ngh DSL:

Kt ni truyn hnh cp lin mng

Cable TV Internet c cung cp thng qua cc ng cp TV. N s dng cp ng trc m tc

truyn ti d liu c th cao hn qua ng dy in thoi.

Cc im chnh:

Mt modem cp c s dng truy cp dch v ny, c cung cp bi nh qun l

cung cp cp.

Modem cp ny bao gm 2 kt ni: mt cho dch v Internet v mt cho cc tn hiu Truyn

hnh cp.

T khi cc kt ni truyn hnh cp lin mng chia s mt thit lp s lng bng thng vi

mt nhm khch hng, v th, tc truyn ti d liu cng ph thuc vo s lng khch

hng s dng Internet ti cng mt thi im.



S di y ch cch Internet c truy cp bi s dng kt ni truyn hnh cp:

Kt ni Internet dng v tinh nhn to

Kiu kt ni ny cung cp mt tc kt ni cao ti Internet. C hai kiu kt ni l: kt ni mt

chiu hoc kt ni hai chiu.

Trong kt ni mt chiu, chng ta ch c th ti d liu v nhng nu chng ta mun ti d liu ln,

chng ta cn mt truy cp dial-up thng qua ISP qua ng dy in thoi.

Trong kt ni hai chiu, chng ta c th ti d liu ln hoc xung bi kt ni dng v tinh nhn

to. N khng yu cu bt c kt ni dial-up no.

S sau ch cch chng ta truy cp Internet bi dng kt ni s dng v tinh nhn to:



Kt ni Internet khng dy

Kt ni ny s dng cc tn s v tuyn kt ni ti Internet v cung cp mt tc truyn ti

cao. Kt ni Internet khng dy c th c nhn bi hoc Wifi hoc Bluetooth.

Cc im chnh:

Cng ngh kt ni khng dy Wifi c da trn cc tiu chun IEEE 802.11 m cho php

thit b in t kt ni ti Internet.

Cng ngh kt ni khng dy Bluetooth s dng sng v tuyn bin ngn v gip to

Mng khu vc c nhn (PAN).

Cc giao thc Internet Transmission Control Protocol (TCP) TCP l mt giao thc iu hng kt ni v cung cp s phn phi d liu end-to-end. N hot

ng nh l b khung pha sau ca kt ni. N trnh by cc c trng sau:

TCP tng ng vi Tng truyn ti (vn chuyn) ca M hnh OSI.

TCP l giao thc iu hng (nh tuyn) kt ni v ng tin cy.

TCP cung cp:



o Truyn ti lung d liu

o Tnh ng tin cy

o Kim sot dng d liu hiu qu

o S hot ng Full-Duplex

o S dng k thut dn knh

TCP cung cp s phn phi gi d liu end-to-end.

TCP bo m tnh ng tin cy bi vic xp xp dy th t cc Byte vi mt tin bo nhn

ang chuyn tip m ch ch n ca Byte k tip m ngun mong i nhn.

N truyn ti li cc Byte m khng c nhn bit vi mt qung thi gian c xc

nh.

Cc dch v TCP

TCP cung cp mt s dch v sau ti tin trnh x l ti Tng ng dng.

Dch v phn phi lung d liu

Cc b m gi v nhn

Cc Byte v cc on (mnh) d liu

Dch v Full-Duplex

Dch v nh tuyn kt ni

Dch v ng tin cy

DCH V PHN PHI LUNG

Giao thc TCP l lung d liu c nh hng bi v n cho php tin trnh gi gi d liu

nh l lung cc Byte v tin trnh nhn thu nhn d liu nh l lung cc Byte.

CC B M GI V NHN

N l khng th cho cc tin trnh gi v nhn gi v thu nhn d liu ti cng mt tc , v

th, TCP cn cc b m lu gi d liu ti cc u gi v u nhn.



CC BYTE V CC MNH D LIU

TCP ti Tng truyn ti nhm cc Byte vo trong mt gi d liu. Gi ny c gi l cc mnh

(on) d liu. Trc khi truyn ti cc gi ny, nhng on ny c ng gi vo trong mt IP

d liu nh (datagram).

DCH V FULL-DUPLEX

Vn chuyn d liu trong ch Duplex ngha l dng d liu trong c hai hng ti cng mt thi

im.

DCH V NH HNG KT NI

TCP cung cp dch v iu hng kt ni theo cch sau:

1. TCP ca tin trnh 1 thng bo cho TCP tin trnh 2 v nhn s ph c

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