01 - Cac Khai Niem Can Ban

7/30/2019 01 - Cac Khai Niem Can Ban

1/13

BM MMT Khoa CNTT Trng H KHTN Tp. HCM 1

Cc khi nim cbnv mng my tnh

Trng Th M Trang

Email: [email protected]

Thng 9 / 2007


Ni dung

1. Mng my tnh l g?

2. Lch s

MMT3. Cc khi nim cbn

4. M hnh mng5. hnh mng6. Cc thnh phn trong mng my tnh

7. Cc ng dng mng


Mng my tnh l g?

Mng my tnh (computernetwork):

Nhiu my tnh k

t n

i v

inhau bng thit b truyn

dn Lin lc v chia s ti

nguyn


Mng my tnh l g? (tt)

Internet: Mng ca mng

L mng kt ni nhiumng my tnh vinhau thnh mt mngc kh nng truy cpton cu


2/13


Mng my tnh lm c g? - 1

Lin lc, trao i thng tin ng tin cy (reliable) Cng bng (fair) Hiu qu (efficient) T 1 ng dng n cc ng dng khc

Chia s ti nguyn Tp tin, th mc,

My in, my fax,


Mng my tnh lm c g? - 2

T pht hin v sa li H d liu Mt d liu D liu truyn b trng D liu n ch khng ng th t

T tm ng i ti u n ch


Phn loi mn g - 1

Theo phm vi (a hnh): Mng cc b (LAN Local Area Network)

Kch thc nh (to nh, phng my, cng ty, ..) Tc cao, t li

R tin Mng th (MAN - Metropolean Area Network)

Nhiu mng LAN kt hp li C phm vi trong 1 qun, huyn, thnh ph Chm, nhiu li, chi ph cao hn LAN

Mng din rng (WAN - Wide Area Network) Nhiu LAN, MAN kt hp vi nhau Phm vi quc gia, chu lc, quc t

Chm, nhiu li, chi ph cao hn LAN, MAN


Phn loi mn g - 2

Theo phm vi hot ng: intranet

extranet internet VPN


3/13


Phn loi mn g - 3 Theo chc nng:

Server Client (Server based): Mt my c th l Client hoc Server Client: yu cu dch v Server: phc v cc yu cu t Client. Thng l my c cu

hnh mnh Thun li: bo mt tp trung, d truy xut, backup Bt li: server t tin, ph thuc vo qun tr mng

Peer to peer: Mt m yva l Client va l Server Khng cn server Thun li: r tin, d thit lp, bo tr Bt li: d liu b phn tn, kh nh v ti nguyn, tnh bo mt

thp


Phn loi mng 4

Theo hnh mng (topology) Bus Ring Star Mesh


Phn loi mn g 5

Theo phng tin truyn dn: C dy

Khng dy Infrastructure Ad-hoc


Ni dung

1. Mng my tnh l g?2. Lch s MMT

3. Cc khi nim cbn4. M hnh mng5. hnh mng6. Cc thnh phn trong mng my tnh7. Cc ng dng mng


4/13


Lch s MMT

tng mm mng ut in lca J.C.R.Licklider (MIT)"a network of such [computers], connected toone another by wide-band communication lines"which provided "the functions of present-daylibraries together with anticipated advances ininformation storage and retrieval and [other]symbiotic functions. -J.C.R. Licklider


Lch s MMT (tt)

Khi u l mng ARPANET nm 1969 Xut pht t vic pht minh ra cng ngh

chuyn mch mch gi ca Leonard Kleinrock(MIT)

J.C.R. Licklider v Lawrence Robert 21/11/1969, mng ARPANETu tin kt

ni 2 ni: Trng H California, Los Angelesv Vin nghin cu Stanford


Lch s MMT (tt)

T 1970s n 1980s: ALOHAnet

Telenet CyclaBITNET CSNET NSFNET .


Lch s MMT (tt)

1990s: nm bng n ca Internet 1990, ARPANETng 1995, NSFNETng Rt nhiu ng dng ra i

Email Web Instant message, ICQ Peer-to-peer file sharing

2000s: P2P, wireless, sensor, gridcomputing, VoIP,


5/13


Ni dung

1. Mng my tnh l g?2. Lch s MMT3. Cc khi nim cbn4. M hnh mng5. hnh mng6. Cc thnh phn trong mng my tnh

7. Cc ng dng mng


Kiu truyn

Unicast T 1 im n 1 im

Broadcast T 1 im n tt c

cc im Multicast

T 1 im n 1 s im

qui nh trc

A

B

A

A B

C


Giao thc - 1

Con ngi

HiHi

Got thetime?2:00

My tnh

TCP connectionreq.

TCP connectionreply.


Giao thc - 2

Giao thc: nh dng d liu trao i

Th

t

thng tin truyn nh

n gi

a cc th

cth trn mng

Cc hnh ng c th sau mi thng tintruyn i hoc nhn c

VD: HTTP, TCP, IP, PPP, Do cc t chc v h ip hi x y dng:

IEEE, ANSI, TIA, EIA, ITU-T


6/13


Bng thng Bng thng (bandwidth):

Lng thng tin c th truyn i trn 1 kt ni mngtrong 1 khong thi gian

L tng n v tnh: bit/s (bps), Mbps, Gbps,

Thng lng (throughput): Bng thng thc t Nh hn nhiu so vi bng thng l thuyt Cc yu t nh hng:

Thit b lin mng Topology mng S lng user trn mng My tnh ca user, server


tr - 1

L thi gian tr ca 1 gi tin Cc nguyn nhn gy ra tr:

Tr do tc truyn (transmission delay) Tr trn ng truyn (propagation delay) X l ti nt (nodal processing) Hng i (queuing delay)


tr - 2

Tr do tc truyn (transmission delay): L thi gian cn thit chuyn mch ht gi tin lnng truyn

Dtrans = L/R (s) R = bng thng ca ng truyn (bps) L = chiu di gi tin (bit)

V d: gi tin c chiu di L = 100bytes. ng truync bng thng R = 10 Mbps Dtrans = 100*8/(10*10242) s


tr - 3

Tr trn ng truyn (propagation delay) Thi gian truyn 1 bit t ni gi n ni nhn Dprop = d/c

d = chiu di ng truyn c = tc truyn (~ 2x10^8 m/sec - 3x10^8 m/sec)

X l ti nt (nodal processing): Dproc L thi gian x l header ca 1 gi tin v quyt nh

chuyn mch gi tin theo hng no Kim li bit Xc nh ura ( v dda trn a ch n.)

Thng rt nh


7/13


tr - 4

Hng i: Dqueue L thi gian gi tin chc y ln ng

truyn Ph thuc: s lng gi tin n trc n

Tng tr khi truyn 1 gi tin:D = Dproc + Dqueue + Dtrans + Dprop


tr - 5 V d 1: tnh thi gian truyn tin t node A sang node B bit:

Khong cch t A n B: 100km tc ng truyn 360.000km/h Trung bnh mi gi tin c kch thc 2MB Bng thng ca ng truyn: 100Mbps Mi gi tin cn 0.01s x l

Tnh: Thi gian gi 1 gi tin. Gi s, ti thi im ang xt, hng i ca A

l rng Thi gian truyn ht 6 gi tin ang chtrong hng i T=0, hng i ca A rng, v bt u nhn 3 gi tin cng lc. T=1(s), A

nhn thm 2 gi tin na. Hi, ti t=0.1(s), bit u tin ca gi tin thnht ang v tr no v thi im B nhn ht gi tin th 5.


tr - 6

Cc lnh dng kim tra thi gian tr Ping Tracert Pathping netstat


Ni dung

1. Mng my tnh l g?2. Lch s MMT

3. Cc khi nim cbn4. M hnh mng5. hnh mng6. Cc thnh phn trong mng my tnh7. Cc ng dng mng


8/13


M hnh mn g - 1

DistributionLayer

Core Layer

Access

Layer


M hnh mn g 2

Tng truy cp mng: cung cp kt ni cho ngi dng cui truy cp

mng

Access Layer


M hnh mn g - 3 Tng phn tn:

Tch hp nhiu tng truy cp mng nh tuyn lung d liu Phn mng thnh nhiu vng broadcast/multicast chuyn mch i tn hiu gia cc loi mng Cung cpc c dch v bo mt, lc d liu, truy cp t xa

Distribution Layer


M hnh mn g - 4

Tng li: khung sn kt ni cc thit b tng phn

tn Nhanh Khng thao tc trn cc gi tin

Core Layer


9/13


M hnh mn g - 5

Khi thit k mng my tnh: Phm vi Thi gian Vn tnh ton Kinh ph Nhn lc


Ni dung


7. Cc ng dng mng


hnh mn g - 1 hnh mng (network topology):

cch thc b tr ng truyn ni ktccntmng Phn loi:

hnh vt l : M t cch b tr ng truyn tht s

hnh logic: M t con ng m d liu tht s di chuyn. Cc kiu hnh mng:

Bus: cc thit b ni trc tipv o mt ng mng chung Star: cc thit b ni trc tipv o mt thit b chung Ring: cc thit b ni vi nhau to thnh vng trn Mesh: 2 thit b bt k c ni trc tip vi nhau Tree: cc thit b ni vi nhau thnh nhiu tng


hnh mn g - 2

Dng bus: cc node chia s chung 1 ng truyn


10/13


hnh mn g - 3

Dng sao (star) Cc node lin kt vi nhau qua 1 node trung

tm


hnh mn g - 4

Dng vng (ring


hnh mn g - 5

Dng li (mesh) Gia tng tin cy ca h thng C 2 loi:

mesh 1 phn (bn phn) mesh ton phn


hnh mn g - 6

Dng cy (tree)


11/13


System is expensive to install

because it uses a lot of cabling.

System provides increasedredundancy and reliability as well

as ease of troubleshooting.

Mesh

If the centralized point fails, thenetwork fails.

Modifying system and adding newcomputers is easy. Centralizedmonitoring and management arepossible. Failure of one computerdoes not affect the rest of the

network.

Star

Failure of one computer can impact

the rest of the network. Problemsare hard to isolate. Networkreconfiguration disrupts

operation.

System provides equal access for

all computers. Performance iseven despite many users.

Ring

Network can slow down in heavytraffic.Problems are difficult to isolate.Cable break can affect many users

Use of cable is economical. Mediais inexpensive & easy to workwith.System is simple and reliable.Bus is easy to extend.

Bus


Ni dung


7. Cc ng dng mng


Cc thnh phn MMT

Bn ngoi mng: Cc thit b u cui Cc phng tin

truyn dn Cc thit b mng Cc ti nguyn mng:

tp tin, my in,


Cc thnh phn MMT (tt)

Bn trong mng: Giao thc Phng thc truyn d liu:

chuyn mch mch (circuit-switching): mi cuc gi chim dng ht vng bng thng c

cp. VD: mng in thoi PSTN

chuyn mch gi (packet-switching) d liu chuyn mch trn mng ri rc theo tng

khc, gi l gi (packet)

VD: mng my tnh


12/13


Chuyn mch mc h - 1

Chim trc ti nguyn cho mtcuc gi Yu cu thit lp ng dn trc

Bng thng, kh nng chuynmch mch

Ti nguyn dnh ring cho tngcuc gi- khng chia s

Nhiu cuc gi c t h nhpchung (multiplexed) trn cngmt ng truyn

m bo khng b nghn mch Khng s dng bng thng hiu

qu nu d liu ri rc (hoc dyc nhng bit rate khng u)

C 2 k thut: FDMA, TDMA


Chuyn mch mc h - 2

FDMA

4 cuc gi

TDMA

Tn s

Thi gian

Tn s

Thi gian


Chuyn mch g i - 1

Mi lung d liu c chia nhthnh cc gi

Cc gi tin chia s chung ti

nguyn mng Mi g i s dng ton b bng

thng Yu cu ti nguyn s dng va Mi gi c thm phn header

lm tng kch thc d liutruyn

Bng thng b chia nh

Cp pht ti nguyn

ng k trc ti nguyn


Chuyn mch g i -2

Cc dng chuyn mch gi: Lu v chuyn mch tip (store and forward) Ct-chuyn mch (cut-through) Fragment-free


13/13


Chuyn mch gi vs chuyn mch mch

chuyn mch gi cho php nhiu ngi dng ngthi hn

Rt p h hpchod liu tc thi Chia s ti nguyn (statistical multiplexing) n gin, khng thit lp trc ng truyn

Tt nghn: lm tr hay mt gi tin Cn nghi thc truyn d liu tin cy, iu khin xungt tt nghn.


Ni dung


7. Cc ng dng mng


Cc ng dng mng

DNS (Domain Name System): RFC1034,RFC1035

FTP (File Transfer Protocol): RFC959

Mail: RFC1521, RFC1522, RFC821,RFC1939

Remote Login, TELNET: RFC854 www (World Wide Web) Instant Message


01 - Cac Khai Niem Can Ban

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