chuongiv_mang lan

8/14/2019 ChuongIV_Mang LAN

1/90

Chng 4. MNG LAN


2/90

11/4/2008 Mng LAN 2

Khi nim

Mng cc b (LAN - Local Area Network) l

mt h thng mng dng kt ni cc my

tnh trong mt phm vi nh. Cc my tnh

trong mng LAN c th chia s ti nguyn

(d liu, my in, my qut,) vi nhau


3/90

4.1.Tng quan v mng LAN

4.1.1.c trng mng LAN4.1.2.Topo mng LAN4.1.3.Phng php iu khintruy nhp ng truyn4.1.4.Thit b


4/90

11/4/2008 Mng LAN 4

4.1.1.c trng

Quy m nh, thng l bn knh di vi km

Mng c th kt ni t hai cho ti hng trm my tnh thngqua cc cp mng hoc ng truyn v tuyn (mng LANkhng dy).

Cc my tnh trong mng LAN thng chia s cp mngchung

Trong mt mng LAN n khng cn c h thng trung

chuyn (routing/switching).

L s hu ca mt t chc


5/90

11/4/2008 Mng LAN 5

c trng(t)

Tc truyn cao, t li

Nhiu chun mng LAN c pht trin trong Ethernet v FDDI l ph bin nht. Ngi tathng gi chung h cc chun mng LAN lIEEE 802.

Tc thng thng trn mng LAN l 10, 100Mb/s v ti nay vi Gigabit (Ethernet).


6/90

11/4/2008 Mng LAN 6


7/90

11/4/2008 Mng LAN 7

4.1.2.Topology mng LAN


8/90

11/4/2008 Mng LAN 8

a. Mng hnh sao

B tr hnh sao gm:

Cc nt: trm u cui, my tnh, thit b mng khc. B kt ni trung tm: iu phi mi hot ng trong mng

B tp trung Hub

B chuyn mch Switch

Hot ng: Mi my tnh u pht tn hiu r a b kt ni trung tm v b

kt ni trung tm pht li tn hiu vo n tt c cc u ra.


9/90

11/4/2008 Mng LAN 9

Mng hnh sao (t)

u im

My tnh kt ni khng cn dng chung ngtruyn cp, trnh c cc yu t gy ngng trmng.

Thit b ti nt b hng, mng vn hot ng

Cu trc n gin, thut ton iu khin n nh

D dng m rng v thu hp


10/90

11/4/2008 Mng LAN 10

Mng hnh sao (t)

Nhc im Kh nng m rng mng hon ton ph thuc

vo kh nng ca thit b kt ni trung tm.

Khi trung tm c s c th ton mng ngng hotng.

Mng yu cu ni c lp ring r tng thit b cc nt thng tin n trung tm.

Khong cch t my n trung tm rt hn ch.


11/90

11/4/2008 Mng LAN 11

b) Mng hnh tuyn

B tr hnh lang:

Cc my tnh v cc thit b khc-cc nt, u c ni nmt trc ng dy cp chung/chnh chuyn ti tn hiu.

Pha hai u dy cp c bt bi mt thit b gi lterminator

Hot ng:

D liu khi truyn i dy cp mang theo a chca ni n


12/90

11/4/2008 Mng LAN 12

Mng hnh tuyn (t)

u im: Dng t dy cp, d lp t, gi thnh r.

Nhc im: S n tc giao thng khi di chuyn d liu vi lu

lng ln.

Khi c s hng hc on no th rt khpht hin, mt s ngng trn ng dy sacha s ngng ton b h thng.


13/90

11/4/2008 Mng LAN 13

c) Mng dng vng

B tr

Khng c thit b trung tm ng dy cp to thnh mt vng khp kn, ng kt nimng i t my ny ti my khc

Thc t c mt on cp ngn ni my tnh ti vng

Hot ng: Tn hiu chy quanh vng theo mt chiu no . Mi thi im chc mt nt c truyn d liu. D liu

truyn i phi c km theo a chc th ca mi my tipnhn.


14/90

11/4/2008 Mng LAN 14

Mng dng vng (t)

u im:

Mng c th ni rng ra xa, tng ng dy cnthit t hn so vi hai kiu trn.

Mi trm c th t c tc ti a khi truynhp.

Nhc im: ng dy phi khp kn, nu b ngt mt ni

no th ton b h thng cng b ngng.


15/90

11/4/2008 Mng LAN 15

d) Mng hnh li

Mng cho php mi ngy my tnh ni vi

mt my khc trong mng bng mt ngcp ring.

Cc my truyn d liu trc tip vi nhau

khng thng qua mt thit b trung gian cngnh khng cn mt giao thc iu khinvic truyn d liu.


16/90

11/4/2008 Mng LAN 16

Mng hnh li(t)

u im: Cc my tnh c kt ni trc tip nn vic truyn d liu c

thc hin mt cch ng tin cy.

Vic mt dy ni b hng th vic truyn d liu gia hai my udy s c thc hin theo mt con ng khc.

Nhc im: Dng qu nhiu dy do vic ci t tr nn rt tn km.

Kh m rng Dng mng ny thng c trin khai kt hp vi cc kiu phn

b khc to ra mt kiu phn b mng kt hp cho mt khuvc i hi tin cy cao.


17/90

11/4/2008 Mng LAN 17

e) Mng dng kt hp

Kt hp hnh sao v tuyn (Star/Bus

Topology)

Kt hp hnh sao v vng (Star/RingTopology).


18/90

11/4/2008 Mng LAN 18

4.1.3. Phng php iu khin truy nhpng truyn

Mng LAN thng l dng mng truyntheo kiu qung b. Hai my tnh khng th cng truyn d liu trn

cng mt ng truyn

Cch thc xc nh ai c quyn truy nhp knhtruyn ti mt thi im nhm trnh ng


19/90

11/4/2008 Mng LAN 19

Phng php iu khin truy nhp ngtruyn (t)

Ba phng php iu khin truy nhp ng truyn:

Chia knh Truy nhp ngu nhin (Random Access)

Phn lt (Taking-turns).

Cc giao thc thuc ba phng php ny c

gom vo trong mt tng con bn di ca tng linkt d liu, tng con MAC.


20/90

11/4/2008 Mng LAN 20

a) Phng php chia knh

Ti nguyn ca ng truyn s c chia

thnh nhiu phn nh (knh), mi phn sc cp pht ring cho mt trm/mt ntmng. Ti nguyn ca ng truyn c thl thi gian, tn s, m. Chia knh theo thi gian Chia knh theo tn s

Chia knh theo m


21/90

11/4/2008 Mng LAN 21

Chia knh theo thi gian

Mt vng thi gian s c chia u thnh cc khe (slot) thi gian bng nhau,mi trm s c cp mt khe thi gian n c th truyn ht mt gitin.

Nhng trm no ti lt c cp cho khe thi gian ca mnh m khng c dliu truyn th vn chim ly khe thi gian , v khong thi gian b chimny c gi l thi gian nhn ri (idle time).

Cc trm s xoay vng (round) truy nhp ng truyn.


22/90

11/4/2008 Mng LAN 22

Chia knh theo tn s

Ph ca knh truyn c chia thnh nhiu bng tn

(frequency bands) khc nhau. Mi trm c gn cho mt bng tn c nh. Nhng trm no

c cp bng tn m khng c d liu truyn th trongtrng thi nhn ri (idle).


23/90

11/4/2008 Mng LAN 23

Chia knh theo m

Mi trm c quyn pht d liu ln ton b

ph tn ca ng truyn ln ti mi thiim. Cc cuc truy nhp ng truyn xyra ng thi s c tch bit vi nhau bik thut m ha.


24/90

11/4/2008 Mng LAN 24

b) Phng php truy nhpngu nhin

Cc trm t do tranh chp ng truyn chung truyn tngkhung d liu mt. S khng c s phi hp trnh t gia cc

trm. Nu c hn hai trm pht cng mt lc, ng (collision) s

xy ra, cc khung b ng s b h hi. Giao thc truy nhp ng truyn ngu nhin c dng

xc nh: Lm th no pht hin ng . Lm th no phc hi sau ng .

V d v cc giao thc truy nhp ngu nhin: slotted ALOHA vpure ALOHA, CSMA v CSMA/CD, CSMA/CA.


25/90

11/4/2008 Mng LAN 25

Giao thc CSMA/CD (CA)

Carrier Sense Multiple Access / Collision

Detection (Collision Avoidance ) - Phngthc a truy nhp c pht hin ng . Multiple Access:a truy nhp

Collision:ng

CSMA: Nghe trc khi ni CD: Nghe trong khi ni

CA: Trnh ng


26/90

11/4/2008 Mng LAN 26


CSMA l giao thc thng dng cho mng

hnh tuyn, cc my trm cng chia s mtknh truyn chung, cc trm u c c hithm nhp ng truyn nh nhau.


27/90

11/4/2008 Mng LAN 27


My trm nghe trc khi mun truyn:

Bn: Ch, tip tc nghe

Ri: Bt u truyn,va truyn va nghe ngngxem c xung t hay khng

Nu pht hin thy xung t : Hy b qutrnh truyn v quay li trng thi ch,nghe


28/90

11/4/2008 Mng LAN 28

ng trong CSMA/CD

Gi s knh truyn c

4 nt Tn hiu lan truyn t

nt ny n nt kia mtmt thi gian nht nh

(tr lan truyn)


29/90

11/4/2008 Mng LAN 29

c) Phng php phn lt

Khng cho ng xy r a bng cch cho cc

trm truy nhp ng truyn mt cch tun t. Thm d (polling):

Trm ch (master) s mi cc trm t (slave) truyn khi n

lt.

Lt truyn c cp pht cho trm t c th bng cch: trm

ch dnh phn cho trm t hoc trm t yu cu v ctrm ch p ng.

Chuyn th bi (token passing)


30/90

11/4/2008 Mng LAN 30

Token Passing

Dng trong mng dngvng, tuyn

Phng thc:

Mt th bi-Token lunchuyn ln lt qua tngnt mng

Nt no gi th bi sc truyn d liu

Gi xong phi chuyn thbi i


31/90

11/4/2008 Mng LAN 31

Token Passing

Mt trm mun truyn d liu th phi i n khi nhn c mt th bi ri. Trm s i bt trng thi ca th bi thnh bn.

Nn gi d liu c km theo a ch ni nhn vo th bi v truyn i theo chiu cavng, th bi lc ny tr thnh khung mang d liu.

Trm ch sau khi nhn khung d liu ny, s copy d liu vo b m ri tiptc truyn khung theo vng nhng thm mt thng tin xc nhn.

Trm ngun nhn li khung ca mnh (theo vng) c nhn ng, i bitbn thnh ri v truyn th bi i.

V th bi chy vng quanh trong mng kn v chc mt th nn vic ng d liu khng th xy ra, do vy hiu sut truyn d liu ca mng khng thayi.

Trong cc giao thc ny cn gii quyt hai vn : Mt th bi lm cho trn vng khng cn th bi lu chuyn na. Hai l, mt th bi bn lu chuyn dng trn vng.


32/90

11/4/2008 Mng LAN 32

So snh cc phng php

Chia knh

Hiu qu, cng bng vi knh truyn c lu lng ln Lng ph khi cp mt knh con cho trm c lu lng nh

Truy nhp ngu nhin

Khi ti nh: trm c th s dng ton b knh truyn

Ti ln:ng tng Phn lt

Dung ha hai phng php


33/90

11/4/2008 Mng LAN33

4.1.4.Cc thit b mng

NIC

Repeater

Hub

Bridge

Modem

Switch

Router

Gateway


34/90

11/4/2008 Mng LAN34

a) NIC (Network Interface Card)


35/90

11/4/2008 Mng LAN35

b) Repeater

Cp trong mng LAN l gii hn v tn hiu b suy

hao trn ng truyn. V d: Gii hn ca cp (CAT 5 UTP) trong mng LAN l

100m

Repeater l b khuych i tn hiu vt l gip tnhiu vt l c th truyn dn i xa hn gii hn ny.

Repeater l thit b tng Physical trong m hnhOSI.


36/90

11/4/2008 Mng LAN36

Repeater (t)

Repeater b khuych i tnhiu 2 port


37/90

11/4/2008 Mng LAN37

Repeater (t)

Repeater

-Khng c qu 4 repeater gia cc host trong mt mng LAN (10MbpsEthernet)

-Hn ch vic tng tr v tng s lng xung t khin hiusut LAN gim st


38/90

11/4/2008 Mng LAN 38

c) HUB

Hub c coi l: Mt b tp trung

Mt Repeater c nhiu cng Hub c t 4 n 24 cng v c th cn nhiu hn

Hub c s dng trong cc mng hnh sao (Ethernet 10BASE-T hay100BASE-T)

Hub ng vai tr l trung tm ca mng. Thng tin vo t mt cng s c(khuych i) a n tt c cc cng

Hub c 3 loi: Pasive Hub: Dng chia s ng truyn vt l, khng khuych i tn hiu

Active Hub: Khuych i tn hiu, cn cung cp nng lng Smart Hub: Tng t Active Hub, c tch hp thm chip c kh nng t ng d li


39/90

11/4/2008 Mng LAN 39

HUB(t)

Hub 4 cng


40/90

11/4/2008 Mng LAN 40

HUB


41/90


42/90

11/4/2008 Mng LAN 42

Bridge(t)


43/90

11/4/2008 Mng LAN 43

Bridge(t)

LAN A

LAN B

Cu ni 2 phn (segment) mng (A, B)


44/90

11/4/2008 Mng LAN 44

Bridge mm do hn: Repeater chuyn i tt c

cc tn hiu nhn c. Bridge c chn lc v chchuyn i cc tn hiu c ch phn mng phabn kia

Bridge thng i hi ngi QTM phi cu hnh

bng a ch, nhng bridge th h mi cp nht tng bng a chkhi thm hay bt thit b.

Repeater hot ng tng 1, Bridge hot ng tng 2

So snh Bridge v Repeater


45/90

11/4/2008 Mng LAN 45

e)Switch

Switch - B chuyn mch


46/90

11/4/2008 Mng LAN 46

Switch(t)

i khi c m t nh l mt Bridge nhiu cng

C kh nng kt ni c nhiu mng li vi nhau tythuc vo s cng

Lc thng tin thng qua cc gi tin nhn c t cc mytrong mng

S dng cc thng tin nhn c xy dng bngSwitch, bng ny cung cp thng tin gip cc gi tin nng a ch.


47/90

11/4/2008 Mng LAN 47

So snh switch v bridge

Switch phc tp hn

Switch hot ng vi tc cao hn Switch cung cp nhiu tnh nng hn

Thit lp cc ng dn truyn thng song

song m khng ng .


48/90

11/4/2008 Mng LAN 48

So snh gia Switch v Hub

Hub truyn mt gi tin t F->C Switch truyn mt gi tin t F->C


49/90

11/4/2008 Mng LAN 49

f)Router

Router nh tuyn (chn ng, chuyn tip)

cc gi tin trn mng cho ti khi chng nch cui cng thit b thuc tngNetwork.

Gi tin cha a ch(IP)


50/90

11/4/2008 Mng LAN 50

Router

Net 2

Net 3 Net 4

Net 1

R4

R1

R2

R3

R: Router_B nh tuyn

Router c th kt ni cc loi mng khc nhau thnh lin mng


51/90

11/4/2008 Mng LAN 51

Router (t)


52/90

11/4/2008 Mng LAN 52

Router(t)

Thng gm: 1 cng kt ni bng thng rng (LAN-WAN/Internet), ISDN,

modemcp, DSL

4-8 cng Ethernet switch (hoc hub)

1 b chuyn i a chmng - NAT (Network AddressTranslator).

1 my ch

DHCP (Dynamic Host Configuration Protocol), 1 my ch proxy DNS (Domain Name Service),

phn cng tng la bo v mng LAN trc cc xmnhp tri php t mng Internet.


53/90

11/4/2008 Mng LAN 53

g)Gateway


54/90

11/4/2008 Mng LAN 54

Gateway(t)

Cho php chuyn i t loi giao thc ny sang

loi giao thc khc Qua Gateway, cc my tnh trong cc mng s

dng cc giao thc khc nhau c th d dng ktni c vi nhau

Gateway phn bit cc giao thc, ng dng VD: chuyn th in t t mng ny sang mng

khc, chuyn i mt phin lm vic t xa, ...


55/90

11/4/2008 Mng LAN 55

h) Modem

Modem (Modulation/Demodulation) c chc nng

chuyn i tn hiu kt ni cc my tnh quang thu bao

Modem khng ni cc mng xa vi nhau,

khng phi l thit b lin mng nh Router

Modem c th lp ngoi hoc lp trong my, vi

cc chun khc nhau


56/90

11/4/2008 Mng LAN 56

Modem ADSL


57/90

11/4/2008 Mng LAN 57

Cng ngh ADSL

Asymmetric Digital Subscriber Line

ng dy thu bao s khng i xng VNPT (MegaVNN)

FPT

Viettel

..


58/90

11/4/2008 Mng LAN 58

Cc li ch ca ADSL

Kt ni lin tc

Tc truy nhp cao Download: 1,5-8 Mbps, Nhanh hn dial-up 140 ln

Upload: 64-640Kbps

truy nhp Internet v s dng in thoi mtcch ng thi

Khng phi tr cc in thoi ni ht


59/90

11/4/2008 Mng LAN 59

Cc ng dng ca ADSL

Truy nhp Internet tc cao

Hi ngh truyn hnh

Video theo yu cu

Truyn hnh trc tuyn

Kt ni mng WAN


60/90

11/4/2008 Mng LAN 60


61/90

11/4/2008 Mng LAN 61


62/90

4.2. Ethernet

4.2.1. Gii thiu chung

4.2.2. Kin trc v n v d liu

4.2.3. Phn loi cng nghEthernet


63/90

11/4/2008 Mng LAN 63

4.2.1.Gii thiu chung

22/5/1973, Robert Metcalfe thuc hng Xerox

PARC bang California, a ra tng h thngkt ni mng my tnh cho php cc my tnh c thtruyn d liu vi nhau v vi my in lazer

Cc my c th trao i thng tin trc tip vi nhau mkhng cn qua my tnh trung tm

M hnh mi ny lm thay i th gii cng nghtruyn thng, gi l mng Ethernet


64/90

11/4/2008 Mng LAN 64

Gii thiu chung(t)

LAN u tin trn th gii chnh l phin bn ban u ca Ethernet


65/90

11/4/2008 Mng LAN 65

Gii thiu chung(t)

Chun Ethernet c cng b u tin vo nm

1980 bi mt tiu ban phi hp gia DigitalEquipment Company, Intel v Xerox.

Ethernet trong giai on u tin truyn vi tc 10Mbpsqua cp ng trc (thicknet), khong cch truyn 2km

Chun Ethernet c mt s hiu chnh nh trongchun cho LAN 802. c cng b bi IEEE (1985)


66/90

11/4/2008 Mng LAN 66

Gii thiu chung(t)

1995, IEEE cng b chun cho 100 Mbps Ethernet

(Fast Ethernet) 1998,1999, IEEE cng b chun cho Gigabit

Ethernet

Cc chun, cc c t Ethernet h tr cc mi

trng truyn khc nhau, bng thng khc nhaunhng khun dng frame v lc nh a chging nhauCc chun v c bn u tng thch.


67/90

11/4/2008 Mng LAN 67

4.2.2. Kin trc v n v dliu

a) Cc thnh phn:

Nt mng Cc thit b d liu u cui (Data Terminal Equipment

DTE): ngun v ch ca d liu

PC, my trm (workstation), my ch tp (file server), my ch in

n (Print server)...

Cc thit b trung chuyn d liu (Data CommunicationEquipment DCE): thit b trung gian trung chuyn frame

repeater, hub, router , Modem, NIC


68/90

11/4/2008 Mng LAN 68

a) Cc thnh phn:

Cc thit b kt ni

Dng kt cc my tnh trong mng v giamy tnh vi cc thit b trung chuyn (DCE)

Transceiver, cp mng UTP, STP, cp quang, ...


69/90

11/4/2008 Mng LAN 69

b)Topology

Topology mng: Mng dng bus tng ph

bin trc y

Trong mt phn onmng, cc nt mng chias cng mt ng trc

Cc phan on mng

c ni vi nau thngqua cc thit b lp vkhuych i tn hiu


70/90

11/4/2008 Mng LAN 70

Topology (t)

Ngy nay: ch yu l mnghnh sao

Mt b chuyn mch trungtm vi nhiu cngEthernet

B chuyn mch c th tolin kt c lp cho hai ntmng bt k

Khng xung t

Khng giao thc a truynhp


71/90

11/4/2008 Mng LAN 71

c)Ethernet v OSI


72/90

11/4/2008 Mng LAN 72

Tng MAC(Media Access Control)

Nhim v:

ng gi d liu, bao gm vic thit lp ccframe d liu trc khi truyn i v kim tra litrong qu trnh nhn tin.

Khi ng qu trnh truyn d liu v khi phc

nu vic truyn d liu b li.


73/90

11/4/2008 Mng LAN 73

Tng MAC-client

Ty thuc vo cc i tng tng ny c nhngchc nng v tn gi khc nhau: DTE: tng ny cung cp giao din gia cc tng trn vi

tng MAC di, n thng c gi l tng Logical LinkControl. (802.1)

DCE, tng ny cung cp giao din cc mng LAN c thtrao i thng tin, cc mng LAN s dng cc cng nghtruy nhp ng truyn khc nhau c th trao i thng tinvi nhau, n thng c gi l cc thc th cu (BridgeEntities).


74/90

11/4/2008 Mng LAN 74

c)Cu trc a ch Mi giao tip mng Ethernet c nh danh duy nht bi a

chMAC 48 bit (6 octet). a ch ny c n nh khi sn xut

thit b. a ch MAC c biu din bi cc ch s hexa (h c s

16). V d:00:60:2F:3A:07:BC 3 octet u xc nh hng sn xut, chu s qun l ca t chc

IEEE. V d 00:60:2FCISCO. 3 octet sau do nh sn xut n nh phn bit bn thn cc

thit b. a chMAC duy nht cho mt giao din giao tip mng

Ethernet. a ch MAC c s dng lm a chngun v ach ch trong frame ca Ethernet.


75/90

11/4/2008 Mng LAN 75

Nhc li

Giao thc ARP dng xc nh xem vi

mt IP l 1.2.3.4 th gi tin nn c gi rangoi vi a chMAC no.

Giao thc RARP dng xc nh IP camt my khi bit a chMAC.


76/90

11/4/2008 Mng LAN 76

d)n v d liu _Khung tin

(frame)

Cu trc


77/90

11/4/2008 Mng LAN 77

n v d liu (t) Preamble: nh du s xut hin ca khung tin, mi mt byte lun

mang gi tr 10101010. Trng ny dng ng b vic truyn vnhn d liu.

SFD (Start Frame Delimiter): Kt thc phn thng tin nh thi, xcnh s bt u thc s ca 1 khung tin. N lun mng gi tr10101011.

Destination , Source : Mang a chMAC ca cc trm nhn v gikhung tin.

Type: Chra giao thc c s dng tng cao hn, thng l IP,

nhng cc giao thc khc vn c h tr - v d: Novell IPX vAppleTalk.

Length: Xc nh kch thc ca d liu (s byte d liu ca lp LLC),trong khung tin tun theo chun 802.3 trng ny thay th cho trngType.


78/90

11/4/2008 Mng LAN 78

n v d liu (t) Data Unit: Cha d liu lp trn c kch thc gii hn t 46

1500 bytes.

Pad: Cha cc bit d liu (gi tr 0) c s dng nhi votrng d liu khi kch thc ca d liu nh hn 46 bytes.

FCS (Frame Check Sequence) mang m sa li CRC (CyclicRedundancy Checksum). Pha gi s tnh ton trng nytrc khi truyn mt khung tin. Pha nhn tnh ton li CRC ny

theo cch tng t. Nu hai kt qu trng nhau, khung tinnhn c c xem l khng c li ngc li khung tin s bloi b.


79/90

11/4/2008 Mng LAN 79

Phn loi khung tin Ethernet

Khung tin Ethernet chia lm ba loi da trn

dng a ch ch ca my nhn Khung unicast

Khung broadcast

Khung multicast


80/90

11/4/2008 Mng LAN 80

Khung unicast

Khung c truyn t my ngun ti mt my ch trong mtphn on mng. Gi s my 1 cn truyn khung ti my 2.

Khung Ethernet do my 1 to ra c a ch: MAC ngun: 00-60-08-93-DB-CF MAC ch: 00-60-08-93-AB-12

Tt c cc my trong phn on mng trn s u nhn ckhung ny. Tuy nhin chc my 2 thy a ch MAC ch cakhung trng vi a chMAC ca giao tip mng ca mnh nn

tip tc x l cc thng tin khc trong khung. Cc my khc sau khi so snh a chs b qua khng tip tc

x l khung na.


81/90

11/4/2008 Mng LAN 81

Khung broadcast

Khung c truyn t my ngun ti tt c cc mykhc trong mng. Cc khung broadcast c a chMAC ch l FF-FF-FF-FF-FF-FF (48 bit 1).

Khi nhn c cc khung ny, mc d khng trngvi a chMAC ca giao thc tip mng ca mnhnhng cc my u phi nhn khung v tip tc x

l. Giao thc ARP s dng cc khung broadcast ny

tm a ch MAC tng ng mt a ch IP cho trc.


82/90

11/4/2008 Mng LAN 82

Khung multicast

My ngun gi khung n mt tp con

(subset) cc my trong mng Ethernet. a ch MAC ch ca khung l a ch c

bit m chcc my trong cng nhm michp nhn cc khung gi ti a chny.


83/90

11/4/2008 Mng LAN 83

4.2.3.Phn loi cng ngh mng Ethernet

Da trn

Tc

Phng thc tn hiu s dng

c tnh ng truyn vt l

V d 10BASE2 10: 10 Mbps

Base: Baseband, Broad, BroadBand

2: Chiu di cp ti a 200 m


84/90

11/4/2008 Mng LAN 84

Phn loi cng ngh mng Ethernet (t)

H thng Ethernet 10Mbps

10Base5. Cp ng trc loi dy, chiu di cp tia cho 1 phn on mng l 500m.

10Base2. Cp ng trc mng, 185m (IEEE lmtrn 200m)

10BaseT. Cp xon i (T-Twisted Pair)

10BaseF. Cp quang (F-Fiber Optic), ra i nm1993.


85/90

11/4/2008 Mng LAN 85

V d

Mng 10Base2


86/90

11/4/2008 Mng LAN 86

V d


87/90

11/4/2008 Mng LAN 87

Phn loi cng ngh mng Ethernet(t)

H thng Fast Ethernet 100Mbps

100BaseT. Cp xon ln cp si quang. 100BaseX. S dng phng php m ha 4B/5B

ca chun FDDI (X)

100BaseFX. S dng cp si quang a ch .

100BaseTX. S dng cp xon cp 100BaseT2 v 100BaseT4. S dng 2 cp v 4 cp

cp xon cp Cat 3 tr ln


88/90

11/4/2008 Mng LAN 88

Phn loi cng ngh mng Ethernet(t)

H thng Giga Ethernet

1000BaseX. S dng pp m ha 8B/10B dng trongh thng kt ni tc cao Fibre Channel cpht trin bi ANSI

1000Base-SX: dng si quang vi sng ngn

1000Base-LX: dng si quang vi sng di

1000Base-CX: s dng cp ng

- 1000BaseT. S dng kiu m ha ng truynring t c tc cao trn cp xon cp


89/90

Thankyou!

Q&AQ&A


90/90

Di tn ca cc knh truyn

thng

chuongiv_mang lan

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