155752604-117741890-Bao-Cao-Nhom-8-Final

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TRNG I HC BCH KHOA H NI

VIN IN T - VIN THNG

BO CO BI TP LN

MN C S TRUYN S LIU

BI S 1

GING VIN HNG DN: TS. PHM VN TIN

NHM SINH VIN THC HIN: NHM S 8

Nguyn Hu Quang T12 - K54 20092085

ng Vn Qun T2 - K54 20092109

Trn Ngc Qun T3 - K54 20092150

Bi Xun Quyt T9 - K54 20092165

Phm Hng Sn T10 - K54 20092268

o c Tn T7 - K54 20092325

H NI 11/2012

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MC LC

I. bi v yu cu .. 3

II. Phn tch yu cu.. 4

1. Phn tch yu cu... 4

2. Thc hin yu cu.. 4

III. Lp k hoch v phn cng cng vic. 5

1. Lp k hoch.. 5

2. Phn cng cng vic . 5

IV. Qu trnh thc hin6

1. Giao thc truyn dn UDP...6

2. Cc phng thc nh tuyn6

3. Theo di s kin trn h thng v cng c Xgraph7

4. Thc hin cc yu cu.9

a. T l chim dng b m...9

b. Phn b Poisson...10

c. Gim gi tin.10

d. Bng thng ca tng lung..12

e. Tr mi lung...12

5. Thc hin m phng..13

a. Kch bn m phng13

b. Kt qu m phng..14

Kt lun..21

Ti liu tham kho.22

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I. bi v yu cu

Cho mng thng tin vi cu hnh nh Hnh 1 di y. Nt s1 pht ra lung gi gi

ti u cui d1, trong khi nt s2 to ra hai lung gi gi ti nt d1 v ti nt d2. C 3

lung thng tin ni trn u s dng giao thc truyn UDP. Kch thc gi do s1 v s2

pht ra tng ng l 1300 byte v 1000 byte; s lng gi pht ra trn mi lung tun

theo phn b Poisson, tc ln lt l 1000 gi/s, 1500 gi/s v 2000 gi/s.

1. Dng kch bn m phng h thng thng tin ni trn vi thi gian m phng di

hn 5 pht.

2. Thu thp s liu m phng v v th t l chim dng cc b m tt c cc

b nh tuyn.

3. Trong mt phin chy m phng, tc pht sinh gi ca mi lung gim i 50

gi/s sau mi khong thi gian 30s, thng k v v th hiu sut s dng bng

thng ca cc lin kt trong mi khong thi gian .

4. Thay i tham s chiu di gi v tc pht sinh gi, v th biu din tr

truyn thng ca cc lung. Nhn xt kt qu thu c.

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II. Phn tch yu cu

1. Phn tch yu cu

Yu cu chung : ci t ubuntu , ci t ns2 , tm hiu cc thao tc c bn trn h

iu hnh m ngun m, cc m phng c bn ca ns2 .

Yu cu bi :

- To c m hnh mng thng tin trn ns2

- Tm hiu v nh tuyn

- Thit lp c s lng gi pht sinh theo phn b Poisson

- Tm hiu v cc giao thc truyn thng UDP

- Cc hm, th tc thay i s lng gi pht sinh

- Tm hiu v cng c x l s liu v v th trn ns2

2. Thc hin yu cu

a. T l chim dng cc b m c tnh nh sau:

50 100%

Vi queueLength l chiu di hng i tc thi.

Chiu di hng i tc thi bng s gi n tr s gi i v s gi b rt

b. Gim tc gi v hiu sut s dng bng thng

- gim tc gi : dng 1 th tc v c sau 30s th th tc c gi li 1

ln.

- Tnh hiu sut s dng bng thng : Tnh bng thng ca tng lung bng cch

s dng Agent LossMonitor lu li nhng gi truyn, sau khi tnh c

bng thng trong 1 chu k th lm sch Agent v thc hin li chu k tip

theo.

c. Tnh tr truyn thng ca cc lung

Xy dng hm trch xut d liu trong trace-file .tr. tr c tnh bng

thi im nhn c gi tin tr i thi im pht gi tin.

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III. Lp k hoch v phn cng cng vic

1. Lp k hoch

Bi tp ln thc hin trong vng 7 tun (bt u t tun 5 v kt thc vo tun 12)

- Tun 1: Ci t ubuntu v ns2, tm hiu cc thao tc lm vic n gin trn

ubuntu, bu trng nhm, tm hiu yu cu v xy dng k hoch thc hin bi

tp ln.

- Tun 2: Tm hiu giao thc UDP, pht gi tin theo phn b Poisson. Thc hin

m phng 1 s h thng thng tin n gin trn ns2

- Tun 3: Code m hnh mng thng tin ca bi s 1

- Tun 4: Tm cch gn cc ngun d liu vo cc node v truyn nh yu cu

bi

- Tun 5, 6: Thu thp v tnh ton s liu v hiu sut s dng hng i, bng

thng, tr truyn thng ca mng v v th t s liu thu thp c.

- Tun 7: Hon thin v kim tra li code, vit bo co v chun b bo v.

2. Phn cng cng vic

Cng vic chung: tt c cc thnh vin trong nhm u phi ci t ubuntu v

ns2, m phng c cc h thng mng n gin; tm hiu giao thc truyn UDP,

bo co cng vic mnh lm c hng tun i vi cc bn cn li trong nhm,

hp nhm nh k 2ln/tun vo cui mi bui hc v chiu th 7.

Cng vic tng thnh vin

STT H v Tn Cng vic Trng thi

1 Nguyn Hu Quang

o c Tn

Tm hiu cng c xgraph v

AWK. Tnh ton t l chim dng

b m v v th.

Hon thnh

2 ng Vn Qun

Bi Xun Quyt

Gim tc pht sinh gi ca

mi lung i 50 gi/s sau mi

khong thi gian 30s, thng k v

v th hiu sut s dng bng

Hon thnh

6

thng ca cc lin kt trong mi

khong thi gian .

3 Trn Ngc Qun

Phm Hng Sn

Xy dng tin trnh Poisson, v

th biu din tr truyn

thng ca cc lung.

Hon thnh

IV. Qu trnh thc hin

1. Giao thc truyn dn UDP

Giao thc UDP (User Datagram Protocol) hay cn gi l giao thc gi ngi dng

l mt trong hai giao thc ct li ca giao thc TCP/IP, cho php ngi dng c th

gi nhng d liu ngn c gi l datagram t my tnh ny n my tnh khc.

UDP khng m bo s tin cy v th t truyn nhn, cc gi d liu c th n

khng ng th t hoc b mt m khng c thng bo. Tuy nhin, UDP nhanh v

hiu qu hn i vi nhng mc tiu nh kch thc nh v yu cu kht khe v thi

gian, giao thc ny hu dng i vi vic tr li cc truy vn vi s lng ln ngi

yu cu.

Nhng ng dng ph bin s dng UDP nh DNS (Domain Name System), ng

dng streaming media, Voice over IP, Trivial File Transfer Protocol (TFTP), v game

trc tuyn.

2. Cc phng thc nh tuyn

NS2 thc thi ba chnh sch nh tuyn: static routing (nh tuyn tnh), session

routing (nh tuyn phin), DV routing (nh tuyn vc t khong cch) v Link-state

(trng thi lin kt).

Dng phng thc rtproto trong lp Simulator xc nh chnh sch nh tuyn

c dng.

o $ns rtproto

o type: Static, Session, DV, cost, multicast-path, LS.

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- Link-state : s dng thut ton SPF (shortest path first) cp nht cc thng tin

v c ch nh tuyn cho cc node trn h thng mng. Mi node s gi bng

m t trng thi ca cc lin kt ring ca mnh ln mng. Ch cc thay i mi

c gi i. u im l tc cao, khng chim dng bng thng nhiu nh

thut ton DV tuy nhin thc hin phc tp. i vi m hnh ln thut ton

ny c th lm tng tr truyn gi tin.

- Distance vector : (cn gi l thut ton Bellman-Ford) gi bng nh tuyn ti

cc node ln cn theo mt chu k nht nh. u im l d thc hin, d kim

tra. Tuy nhin thi gian cp nht lu, chim dng bng thng ln trn mng.

- Static routing : Phng thc tnh ton nh tuyn Static l phng thc tnh

ton ng truyn mc nh trong NS-2. Phng thc ny s dng thut ton

SPF. Thut ton tnh ng truyn chy chnh xc mt ln ti lc khi ng

m phng. Khi cu trc mng thay i phi cp nht li, do ch thch hp

trong h thng n gin, c kt ni n v ng truyn d liu c xc

nh trc.

- Session: S dng thut ton SPF tnh ton ti u ng truyn, bng nh

tuyn s c cp nht ngay lp tc khi topo mng c s thay i.

3. Theo di s kin trn h thng v cng c Xgraph

a. Cc lnh c bn dng theo di cc s kin trn h thng

- Cn bng cp pht b m cho tt c cc file theo di: $ns flush-trace

- To mt i tng theo di:

Cu trc: create-trace {type filename scr dst}

V d : $ns create-trace Drop $tf $n0 $n2

- Theo di tt c cc s kin trn h thng:

$ns trace-all $trace_file

b. Cu trc file trace

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Mi mt lnh theo di trong cc lnh trn s c cc cu trc u ra khc nhau.

y chng ta ch xt n cu trc file u ra ca lnh trace-all. Vi cc cng c

phn tch file d liu c sn nh awk, grep, perl,. Chng ta c th c c tt c cc

thng tin mong mun trong qu trnh h thng mng c m phng bng cch phn

tch file trace-all.

File trace c t chc trong 12 trng nh trong hnh di

- Trng u tin m t loi s kin, c cho bi mt trong 4 k t r, +, -, d

tng ng vi cc trng hp nhn ( u ra ca link), xp vo trong

hng i (enqueued), ri khi hng i (dequeued), b hy (dropped)

- Trng th hai biu din thi gian s kin xut hin.

- Thng bo node input ca link ni s kin xy ra.

- Thng bo node ouput ca link ni s kin xy ra.

- Loi gi tin ( v d TCP, CBR, tn loi tng ng vi tn ca application m

chng ta t, v d trong phn trc th application TCP c gi l tcp).

- Kch c gi tin.

- Mt vi loi c. Chng ta s xt phn sau.

- Flow id (fid) ca Ipv6 m ngi dng thit lp cho mi lung (flow) ti u

vo OTcl cript. Ta c th dng trng ny phn tch kt qu, cng nh

thit lp mu sc cho cc lung trong m phng NAM.

- a ch ca ngun, ni pht gi tin, c cho di dng node.port.

- a ch ca ngun ch, ni nhn gi tin, c cho vi cng dng nh trn.

- S chui cc gi tin ca mt lp giao thc mng. Mc d thnh phn UDP

trong mng thc t khng c s cc chui nhng ns vn gi li cc vt (track)

phn tch kt qu.

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- Trng cui cng ghi ch s id ca gi tin (unique id of packet).

c. Xgraph

Xgrap l mt cng c v th c cung cp bi ns. Xgraph cho php chng

ta to ra cc file postcript , nh , v 1 s nh dng khc bng cch n vo

Hdcpy. cu lnh gi Xgraph c th c khai bo trong kch bn TCL do c

th xut ra ngay th khi kt thc m phng .

u vo ca Xgraph l 1 hoc nhiu file cha mi cp gi tr x-y trn 1 dng

(mi dng s cha ta ca 1 im trn th ) . V d lnh : Xgraph f1 f2 s

v ra trn cng 1 th ca file f1,f2

Mt s la chn khi s dng Xgraph :

- Title : -t ten_do_thi

- Kch thc : -geometry xsize x ysize

- Tiu cho cc trc : -x xtitle y ytitle

- Mu ca ch v li v

- Mu nn bg

4. Thc hin cc yu cu

a. T l chim dng b m

T l chim dng cc b m c tnh nh sau:

50 100%

Vi queueLength l chiu di hng i tc thi, c tnh bng s gi n tr

s gi i v s gi b rt.

Code:

Vi hng i ca lin kt gia node 3 v node 4, t l chim dng hng i

c lu trong file queuesize.tr

set qfile [$ns monitor-queue $node_3 $node_4 [open queue.tr w] 0.5]

[$ns link $node_3 $node_4] queue-sample-timeout;

proc QueueLength {} {

global ns qsize qfile node_3 node_4

10

# thoi gian lay mau la 0.5s

set time 0.5

set now [$ns now]

$qfile instvar parrivals_ pdepartures_ pdrops_

# ty le chiem dung bo dem: queueLength/50 *100% =

queueLength*2 %

puts $qsize "$now [expr 2.0*[expr $parrivals_-$pdepartures_-

$pdrops_]]"

set bdepartures_ 0

$ns at [expr $now + $time] "QueueLength"

}

Sau khi c file queuesize.tr ta v c th t l theo cu lnh:

exec xgraph queuesize.tr -geometry 800x400 -t "Queue occupancy rate" -

x "secs" -y "percentage(%)" &

Hng i ca lin kt gia cc node khc c tnh tng t.

b. Phn b Poisson

Ta xy dng tin trnh Poisson qua mt i tng ExponentialOn/Off vi cc

thnh phn tham s:

. packetsize_ dung lng c nh ca gi d liu

. burst_ time_ thi gian bt khi to

. idle_ time_ thi gian tt khi to

. rate_ tc ca gi

to ra tin trnh Poisson ta cho tham s burst_time_ v 0 v idle_time bng

1

ca tin trnh Poisson.

c. Gim gi tin

- Ngun s1 pht cc gi tin vi tc l 1.3 MBps

- Ngun s2 pht ra 2 lung vi cc gi tin tc l 1.5MBps v 2MBps

- C sau 30s ngun s1 v s2 gim tc gi l 50 gi/s nn ta c lng gim

sau 30s l

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s1: 50 * 1300 = 65000 bytes

s2: 50 * 1000 = 50000 bytes (2 lung)

- Khi thay i s gi () s dn n idle_time_ v rate_ thay i. Cch tnh

idle_time_ nh sau:

1

__ = , vy sau khi gim th

idle_time_ = 1

50

- Rate c tnh nh sau:

s1: rate_ = rate_ 65000 (bytes)

s2: rate_ = rate_ 50000 (bytes)

Sau khi tnh c rate_ v idle_time ca 3 lung ta lu trong cc file

trafficfile1.tr trafficfile2.tr trafficfile3.tr

Code:

set time30 30

proc PackageDecrease {} {

global ns traffic1 traffic2 traffic3 time30 TrafficFile1 TrafficFile2

TrafficFile3

set now [$ns now]

set idle1 [$traffic1 set idle_time_]



set rate1 [$traffic1 set rate_]



$traffic1 set idle_time_ [expr 1.0/[expr 1.0/$idle1 - 50]]



$traffic1 set rate_ [expr $rate1 - 65000]



# luu cac gia tri rate va idle_time vao file

puts $TrafficFile1 "$now [$traffic1 set rate_] [$traffic1 set idle_time_]"



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$ns at [expr $now + $time30] "PackageDecrease"

}

d. Tnh bng thng ca tng lung

S dng Agent LossMonitor lu li nhng gi truyn, sau khi tnh c

bng thng trong 1 chu k th lm sch Agent v thc hin li chu k tip theo.

Code

proc BandWidth {} {

global ns sink1 sink2 sink3 BwFile1 BwFile2 BwFile3

set time 3

set bw1 [$sink1 set bytes_]



set now [$ns now]

puts $BwFile1 "$now [expr $bw1/$time*8/1000]"



$sink1 set bytes_ 0

$sink2 set bytes_ 0

$sink3 set bytes_ 0

$ns at [expr $now+$time] "BandWidth"

}

e. Tnh tr ca mi lung

- Da vo nh dng ca file trace ta thu thp c s liu tnh tr xy ra

trn ng truyn.

- Tr ca cc gi tin c tnh nh sau: thi im gi tin n node ch tr i

thi im gi tin node gi.

- Vic ny c thc hin bng hm vit trong file .awk. Hm c vit nh

sau(vi lung 1 t node 0 ti node 8)

BEGIN {TimeSend[50000];TimeReceive[50000];Delay[50000]}

{

# doc gia tri trace-file theo cot

action = $1;

time = $2;

from = $3;

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to = $4;

type = $5;

pktsize = $6;

flow_id = $8;

src = $9;

dst = $10;

seq_no = $11;

packet_id = $12;

if((action=="+")&&(from == "0"))

TimeSend[packet_id] = time;

if((action=="r")&&(to == "8"))

{

Timereceive[packet_id]=time;

Delay[packet_id] = Timereceive[packet_id]-

TimeSend[packet_id];

print packet_id" "Delay[packet_id];

}

}

END {}

- xut d liu ra file phc v vic v th ta dng cu lnh sau

exec awk f >

V. Thc hin m phng

1. Kch bn m phng

Thi im(s) Mc ch

0.0 Bt u thc hin:

- Tnh bng thng

- Tnh t l chim dng hng i

- Lung 1,2,3 truyn d liu

30.0 Bt u gim tc gi 50 gi/s sau chu k 30s

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300.0 Lung 1,2,3 kt thc truyn d liu

301.0 ng cc file trace v data

V th t l chim dng b m, hiu sut s dng bng

thng v tr ng truyn

Kt thc m phng

2 Kt qu m phng

a. Mng cc lin kt

b. T l chim dng b m ca cc lin kt

15

Lin kt gia node 1 v node 3


16



17



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c. Hiu sut s dng bng thng

ng mu , xanh dng v xanh l cy tng ng vi cc lung 1,

lung 2 v lung 3.

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d. Tr ng truyn

Tr trn lung 1

Tr trn lung 2

20

Tr trn lung 3.

21

KT LUN

Mn c s truyn s liu l mt mn hc chuyn ngnh quan trng v hu

ch. N cung cp nhng kin thc c bn nht cho sinh vin c nh hng theo

chuyn ngnh in t vin thng. Theo quan im hc phi i i vi hnh, em

thy vic nh trng v cc Thy c to iu kin chng em c c hi c lm

bi tp ln l mt vic rt c ngha. bi chng em c giao cng rt ph hp

vi trnh hin ti ca chng em. Sau khi hon thnh bi tp ny chng em

hc hi v tch ly c rt nhiu kin thc. Trc tin phi k n l kin thc

v mng thng tin, cc giao thc truyn v gi gi tin,.. Th hai phi k n l

bit cch s dng phn mm m ngun m v cng c h tr thit k mng rt hu

hiu l NS2.

Mc d c gng ht sc nhng chc chn bi lm ca chng em cn

nhiu thiu st, mong Thy gp cho chng em nhng nhn xt qu bu bi tp

ln ny c hon thin hn.

Li cui, nhm chng em xin knh chc Thy sc khe, cng tc tt, v gt

hi c nhiu thnh cng hn na trong o to cng nh nghin cu!

Nhm chng em xin chn thnh cm n!

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Ti liu tham kho

1. Slide bi ging C s mng thng tin ca Thy Phm Vn Tin

2. Ti liu tham kho NS2 (Ns2_manual, Introduction to Network Simulator NS2

Teerawat Issariyakul)

3. Ti liu hng dn NS2 http://www.isi.edu/nsnam/ns/tutorial/

Documents

155752604-117741890-Bao-Cao-Nhom-8-Final