1CHUYN

Cc k thut m bo cht lng mng IPGing vin: TS. Nguyn Chin Trinh

in thoi: 0915400946 E-mail: chientrinh@gmail.com

2Ni dung

Tng quan v cht lng dch v (QoS).

Cc tham s nh gi cht lng mng IP.

Cc k thut m bo QoS.

Mt s m hnh m bo QoS.

Cc ni dung chuyn .

3Cht lng mng NP

Network Performance l nng lc ca mt mng (hoc l phn mng) cung cp chc nng lin quan n truyn thng tin gia nhng ngi s dng.

Cht lng mng c o lng thng qua cc tham s c ngha i vi nh cung cp mng v c dng cho nhng mc ch thit k, nh cu hnh, khai thc v bo dng h thng.

NP c nh ngha mt cch c lp vi cht lng thit b u cui v nhng hot ng ca ngi s dng.

4Chat lng dch v QoS

QoS l kt qu tng hp ca cc ch tiu hiu nng dch v th hin mc hi lng ca i tng s dng dch v .

Cc yu cu QoS ca ngi s dng/khch hng: l bng k khai mc dch v ca ngi s dng/khch hng v mt dch v, c th c din t mt cch khng phi l k thut. .

QoS c xut bi nh cung cp: l mc cht lng dch v c mong i cung cp cho khch hng bi nh cung cp dch v .

5S khc bit gia QoS v NP

Tham s QoS

ch yu

Tham s NP

ch yu

Speed

(Tc )

Throughput

(Thng lng)

Accuracy

( chnh xc)

Error Rate

(T l li/ Mt gi)

Dependability

(Tnh tin cy)

Delay

Delay Variation or Jitter

(Tr, Bin thin tr)

6Tham s cht lng dch v QoS (v d 1)

B cc tham s v ch tiu cho cht lng dch v VoBB

STT

Tn tham s Ch tiu

1. T l cuc gi c thit lp thnh cng

95%

2. Tr dch v u cui-u cui 150ms

3. Bin thin tr u cui-u cui 50ms

4. T l mt gi 1%

5. MOS 3.5

6. TDT 1s

7. CST 3s

8. ECT 2s

9. Tr sau quay s PDD 2s

7Tham s cht lng dch v QoS (v d 2) Ch tiu truyn dn HDTV

Tc lung

(Mbps)

(1)

Tr, ms

(2)

Rung pha, ms

(3)

Thi gian li cc i,

ms

(4)

Chu k tn tht

gi IP, gi IP

(5)

Khong tn tht gi, s kin

li/4gi

(6)

T l li gi lung IP video

(7)

8 < 200

< 50 16 < 14 1 1,28 E-06

10,0 < 200

< 50 16 < 17 1 2,24 E-06

12 < 200

< 50 16 < 20 1 5,22 E-06

8Tham s cht lng dch v QoS (v d 2) Ch tiu tng tc thi gian IPTV

V d Loi Tr ln nht, ms

Cc thao tc trn giao din ngi s dng

Cun EGP. Bm nt iu khin t xa VoD cho ti khi ch th trn mn hnh lnh c nhn (v d k

hiu tm dng c hin th)

Tng tc

200

Chuyn knh Thi gian t khi bm nt iu khin t xa cho ti khi knh c

hin th n nh trn mn hnh

p ng

2000

Thi gian khi ng h

thng

Thi gian t khi bt ngun STB ti khi knh c hin th.

30.000

9YU CU I VI CC THAM S NP

L nhng tham s c trng v c nh hng chnh n cht lng mng.

L nhng i lng c kh nng o c

S dng cho mc ch ca nh cung cp mng/dch v vin thng, p ng yu cu nh gi

Ph hp vi cc tiu chun, qui nh ca B v cc tiu chun quc t.

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CU TRC MNG

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nh gi cht lng theo lp

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Cc tham s cht lng mng lp IP

Tr truyn gi tin mt chiu.

Bin ng tr truyn gi tin.

tn tht gi tin.

Mc li gi tin.

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Tr truyn gi tin mt chiu IPTD

Tr mt chiu ca mt gi tin c tnh bng thi gian gi tin c truyn i c tr i thi gian nhn gi tin mong mun t c .

Tr gi trn mt ng end-to-end gm 4 thnh phn ti mi nt mng.

A

B

propagation

nodalprocessing queuing

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Tr truyn gi tin mt chiu IPTD

Tr x l: kim tra bit li, xc nh tuyn ra.

Tr hng i: thi gian i trong b m truyn i, ph thuc vo tnh trng tc nghn ca mng.

Tr truyn dn: thi gian truyn gi tin.

Tr truyn lan: tr truyn thng tin trn ng, tnh theo khong cch ca ng nh tuyn.

200 km -> 1ms

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Bin thin tr IPDV

Bin ng tr gi l chnh lch tr gia 2 gi hay gia mi gi so vi mt i lng tham chiu nh tr trung bnh hay tr ti thiu trong mt chui gi c cng ngun v ch.

Bin ng tr gi c th c nh lng da trn kt qu so snh thi gian gi n im o v gi tr tham chiu c chn t gi tr tr ca gi u tin (i), gi tr tr nh nht (ii) hoc gi tr tr trung bnh.

Theo qui nh: Bin ng tr c tnh bng hiu ca gi tr o tr ln nht tr i gi tr o tr nh nht.

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Bin thin tr IPDV

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V d v tr v bin thin tr trn mng

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V d v tr v bin thin tr trn mng

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tn tht gi tin IPLR

Tham s ny c tnh bng tng s gi tin b tn tht so vi tng s gi tin pht i.

Gi gi i khng n c ni nhn, hay pha gi khng nhn c gi phn hi trong khong thi gian xc nh.

V phng din o mt gi c th xem nh trng hp c bit ca tr gi vi gi tr tr vt qu mt ngng thi gian xc nh .

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Cc tham s cht lng lp TCP

Tham s v tc

+ Tr thit lp kt ni

+ Thng lng truyn d liu

+ Tr xa kt ni

+ Thng lng kt ni

Tham s v chnh xc v tin cy:

+ T l li thit lp kt ni

+ T l tht bi thit lp kt ni

+ T l mt kt ni sm

+ T l tht bi xa kt ni

Tham s v kh dng

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Cc tham s cht lng lp cao

Tr giao thc lp cao:

+ Tr p ng dch v lp cao (HLSRD)

+ Tr xc thc lp cao (HLAD)

+ Tr truyn d liu lp cao (HLDTD)

+ Tr dch v lp cao (HLSD)

Tham s sn sng ca giao thc lp cao:

+ T l thnh cng thit lp kt ni (CESR)

+ T l thnh cng dch v (SSR)

+ kh dng ca dch v (SA) :

SSR> SSRth

HLSD

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Cc tham s tr

1- Tr truyn ti mng truy nhp2- Tr truyn ti mng li3- Tr x l xc thc4- Tr x l ng dng

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2

3

4

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V D, TR P NG DCH V (HLSRD)

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Thng lng truyn d liu

Thng lng truyn d liu c biu din bng cch chia tng s byte gi i trong mt pha truyn d liu cho khong thi gian gia gi tin u tin c gi i v gi tin cui cng n. Thng lng truyn d liu hng ln v hng xung c phn bit.

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Yu cu cht lng dch v

wide range of user requirements, depending on application

0%

Packet Loss

Command/ control(eg Telnet, Interactive

games)

Conversationalvoice and video

Voice/videomessaging

Streamingaudio/video

Transactions (eg E-commerce,Web-browsing, E-

mail access)

Messaging, Downloads

(eg FTP,still image)

Fax

Background(eg Usenet)

5%

100 msec 1 sec 10 sec 100 sec

Interactive Responsive Timely Non-critical

Delay

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Phn chia QoS class

QoS Class

Loi ng dng

V dService Class

802.1P DiffServ Codepoint

MPLS EXP

Class 0Routing

ProtocolsRSVP, OSPF, ISIS,

BGPControl 6 CS-6 EXP 6

Class 0 VoIP Voice Telephony

5

EF

EXP 5Class 2

Voice Application Signalling

SIP, H.248, IGMP Signalling EF

Class 2Precision

Time Distribution

IEEE1588v2 Signalling EF

Class 2 VideoVideo on Demand,

Broadcast TV

Broadcast video

4

AF41

EXP4

Class 1Network

ManagementSNMP, SSH OAM AF41

Class 3Enterprise

Data 1

Point-to-Point, Multipoint-to-

Multipoint services

High throughput

data3 AF31 EXP 3

Class 4Enterprise

Data 2

Point-to-Point, Multipoint-to-

Multipoint services

High throughput

data2 AF21 EXP 2

Class 5

Internet Traffic

Business HSI (FTTH)

Standard

1

Default

In-profile

EXP 1

Class 5Residential HSI (DSLAM, FTTB,

FTTC)0

Out-of-profile

EXP 0

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Ch tiu cht lng mng ton trnh trong cung cp dch v

Tham s

QoS Class Tr truyn gi tin mt

chiu

(IPTD)

Bin ng tr

(IPDV)

T l tn tht gi tin

(IPLR)

T l li

gi tin

(IPER)

T l b qua gi tin

(IPDR)

Class 0 100 ms 50 ms 1 103 1 104 -

Class 1 400 ms 50 ms 1 103 1 104 -

Class 2 100 ms U 1 103 1 104 -

Class 3 400 ms U 1 103 1 104 -

Class 4 1 s U 1 103 1 104 -

Class 5 U U U U -

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Pht trin ca cc k thut QoS

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Cc bin php m bo QoS

Phng nga tc nghn:

o Chp nhn kt ni (Admission control)

o Trafic shaping

Cc k thut m bo QoS.

X l khi c tc nghn, s c: truyn li, gim ti, d phng, nh tuyn li.

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X l QoS trn b nh tuyn

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Qun l hng i RED

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Qun l hng i tch cc

Qun l theo chiu di hng i: RED, WRED,

Qun l hng i theo tc lu lng: BLUE, RAQM, .

Kt hp: REM,....

Thng bo tc nghn ECN

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Lp lch

WRR, WFQ, CB-WFQ,

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Chia ct lu lng

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M hnh IntServ

RSVP

Tnh ton ti nguyn m bo QoS

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M hnh DiffServ

MPLS, K thut lu lngTE, RSVP-TE

M hnh DiffServ

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Gi cc chuyn

M hnh lu lng: m hnh Markov, long-rang dependent,

Chp nhn kt ni (AC).

Cc k thut qun l hng i tch cc.

Cc k thut lp lch.

K thut chia ct lu lng.

Giao thc RSVP, RSVP-TE.

K thut lu lng MPLS.

M hnh DiffServ.

Tnh ton ti nguyn: bng thng, b m tha mn cc tham s QoS (loss, delay).

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Bo co chuyn

cng: tn chuyn ; mc tiu, ni dung, kt qu. Np li cho thy sau 2 tun.

Bo co chuyn : 10-20 trang.

Bo co kim tra (10 pht/ sinh vin): Bo co5 pht (slides); Hi kim tra.

nh gi: Ni dung bn bo co, trnh bybo co trn lp, tr li cu hi.

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