Upload
nguyen-thanh-tuyen
View
36
Download
0
Embed Size (px)
DESCRIPTION
Tài Liệu Công Nghệ Internet Tiếng Việt online từ cơ bản đến nâng cao
Citation preview
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 1
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 2
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 3
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 4
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 5
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 6
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 7
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 8
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 9
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 10
......................................................................................................................................... 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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 11
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 12
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 13
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 14
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 15
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 16
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 17
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 18
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 19
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 20
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 21
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 .
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 22
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 23
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 24
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 25
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 26
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 27
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 28
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 29
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 30
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 31
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 32
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)
Tng ny thc hin cc chc nng sau:
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 thc hin cc chc nng sau:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 33
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 34
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).
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 35
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 36
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 37
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 38
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 39
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 40
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 41
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 42
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 43
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 44
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).
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 45
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 46
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 47
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
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 48
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)
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 49
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 50
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 51
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:
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 52
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.
http://vietjack.com/internet_technologies/index.jsp Copyright vietjack.com
http://vietjack.com/ Trang chia s cc bi hc online min ph Trang 53
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