ĐÁNH GIÁ CHẤT LƯỢNG DỊCH VỤ THOẠI VOIP

HC VI 
KHOA VI
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 
TT NGHIP I HC

 





ng dn 
c hin 
Lp : D06VT1
 : 2006  2010
H 


 / 2010

  T NGHII HC

H  : 
Lp : D06VT1
 : 2006  2010
c n T - Vi

 


N 
Ni dung c ba ph
 
 
 



 010
 2/2010


ng d


HC VI

CI CH T NAM
c Lp - T Do - H

KHOA VI
***
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 D06VT1
NHNG DN




















m: (bng ch 




ng dn




 D06VT1
NHN BIN
























n bin





D06VT1 i

 i
 iii
 v
 1
  2
1.1  2
1.2  3
1.2.1  3
1.2.2  4
1.2.3  6
1.3  14
1.3.1  14
1.3.2  15
1.3.3  16
1.3.4  17
1.3.5  19
1.4  21
1.5  22
1.5.1 PC to PC 22
1.5.2 PC to Phone 23

1.5.3 Phone to Phone 24
1.6  24
1.7  25
  27
2.1  27
2.2 -model) 32
2.2.1  32
2.2.2  33
2.3  43
2.3.1  43


D06VT1 ii
2.3.2 
 46
2.3.2.1 ng, kch bn 47
2.3.2.2  48
2.3.2.3 Kt qu ng 53
2.4  57
  58
3.1  59
3.2 n 60
3.3  62
3.3.1  62
3.3.2  63
3.3.3  65
3.4  67
 68
 69



D06VT1 iii



  mi mng VoIP chun H.323 3
 giao th 4
 c ca h thng VoIP 5
 H thng VoIP d 7
 Thit b u cui H.323 8
 Chn ca gateway H.323 9
 Gatekeeper H.323 13
nh 1.8 c ca MCU 14
  18

 t lp cuc gi qua Proxy 20
 t lp cuc gi  ch  Redirect Server 21
 Kt ni t  22
 Kt ni t n thoi 23
 Kt ni t n thoi tn thoi 24
  28
 PESQ: ca ti  (20ms) 29
  31
 Kt ni tham kho c 33
  tr trong h thng thoi qua nn IP 44
 ng logic ca doanh nghip 47
 ng trong phn mm OPNET 48
 C 49
 C 49
 2.10 C 51
 C 52
 C 52
 ng VoIP gn trong mng 53
 Kt qu xp chng VoIP gn 54


D06VT1 iv
Kt qu tr End-to-End 54
  55
 Hiu sut s dng trong Router 55
  56
 Kt qu  57
 Cng VoIP 178 ca Viettel 60
  62
  mc ca VNPT 63



 S t gi 22
 i 25
  tm thi cho h s  41
  m 42
 Thng nm 50


















D06VT1 v






DSL
Digital Subcriber Line

ETSI
European Telecommunications
Standard Institute


GSM
Global System for Mobile

HTTP
HyperText Transfer Protocol

Ie
Impairment equipment

IETF
Internet Engineering Task
Force


IP
Internet Protocol

ISDN
Integrated Services Digital
Network


ITU
International
Telecommunication Union

LAN
Local Area Network

LSTR


MCU
Multipoint Control Unit

MGC
Media Gateway Controller

MGW
Media Gateway

MOS
mean opinion score metal
oxide semiconductor

Nc
Circuit Noise

OLR
Overall Loudness Rating


OSI
Open Systems Interconnection
Reference Model


PCM
Pulse Code Modulation

PESQ
Perceptual Evaluation of
Speech Quality


PSTN
Public Switched Telephone
Network


Qdu
Quantizing Distortion Unit

QoS
Quality of Service

RLR
Receive Loudness Rating

RTP
Real-Time Transport Protocol



SGW
Signalling Gateway

SIP
Session Initiation Protocol



D06VT1 vi
SLR
Send Loudness Rating

SS7
Signaling System # 7

STMR

Masking Rating

TA
Telephony Adapter

Ta
Absolute delay

TCP
Transmission Control Protocol

TELR

Talker Echo Loudness Rating

Tr
Round-Trip Delay

UDP
User Datagram Protocol

VoIP
Voice over Internet Protocol
Internet
WAN
wide area network




D06VT1 1

Khi khoa hc k thui to ra nhiu ca ci vt
ch ginh dn ti thi k
  n nay.  nay t nhi
thc v

c gi gim xung rt nhiu, mang li ln
 m bc chng dch v
i s di nhau mt
 n tng dch v  a
c thc hi




 


th

  

     


III

Trong sut thi k  c s t, ch bo ca
i li cthy ,
c ting dn em trong sut th 
tt c c thnhi bc
tc hi . Em mong nhc nhi 
  

c hi



D06VT1 2
 

1.1 
T khi Alexander Grn tho
tn tho t d thii vi, t chic
n thoi c nh trong mn nhn thong cm tay ca t
n thoi mang li d
  kt n
p vich v truy

c gc l thi vc g
c t  tin phi tr rt tng ln ti l
p th u kt ni quc t. T t cu

mng v  trong vio ra mt th gi v n
      n trong bi c     bi 
i truyn thng t ra thi u hn ch v mt
m v  c gi VoIP r t
nhiu so vn thoi chuyn mn th dng
m nh  truyu tho 
hiu thoc g 
c gng cho mt cuc gi
s gig ch phi tr  dn m
ch v 
c g
Internet Telephony, IP Telephony, Broadband Telephony, Voice over Broadband.
          i gian th   
 t ni trong m  
c chuy li
lc chuyn thit b ci nhng truyn kt ni 
 
i s dng cn thop s
nghi thu chua IETF) hay H.323 (ca ITU-T), kt ni ti mt
ta doanh nghip dch vng :
- dng ta vn phi quay
s c gng.


D06VT1 3
Ting cc :
Call setup : i gnh v a ch
i nhu 1 kt n c vi nhn (b). Khi
a ch i nhn t
gii s thit lp 1 kt ni d liu voice.

Voice data proccessing : ng nghe hay microphone, gi
tn t  s
c chuy u s b s dng thu c bi chuyi.
Nhng thit b n thoi h tr VoIP
i ng dm (softphone), nn thoi
t b u hp chuyi (Telephony Adapter -
u s i nhm tit kii l
 o m li c vn
chuyng IP. Trong sut tit giao thc 
  u khin cuc gt lp, quay s, ngt kt ni
- m b tin c
chng dch v 

1.2 
1.2.1 
Khuyn ngh ca ITU-T v n t thng truy
n dn m  mt h tng mng bao gm
u cuu khich v c s
dng cho truyn (voice, video, data).

  mi mng VoIP chun H.323


D06VT1 4
1.2.2 
H.323 cung cp nhiu loch v  voice, video, data. 
1.2 minh h

 
Ti lp ng dng, dch v Audio bao gn G (G.711, G.722, G.723.1,

G.728, G.729), dch v Video bao gm cac chu
c RTCP, RAS, RTP t lp truyn ti dn giao thc
UDP.
 Vi dch v d liu/ fax : s dng chu
 li
 Vch v b sung : ch nm trong lp truyn tc
u khin, dn TCP.
n ngh giao tha ITU ho
  u khi  t np, tr   nh tuyn
cuc gi.
 c t o mu cu
H.245.
 c t ch v b 
ch v chuyn cuc gi, chuyng cuc gi, gi cuc gi, dng
cuc gi , i cuc gi, ch dn ch, nhn d
cuc gu cuc g dn cuc gi.


D06VT1 5
 c t ng giu cui H vu cui chuyn
m
RTP (Real-Time Transfer Protocol) : Giao thc vn chuyn thi gian thc cung
cn chuyng dng truyn d liu thi gian thc
     li     ch v m   c
m gi ngua ch m bo chng dch v
chch v thi gian thc b  liu UDP trong H.323.
m bao giao thc thi gian th
trong mc hiu khin lung, nhn dng lu
ng thi gian thc.
c ca h thng VoIP s dng H.323

cho Audio.

 c ca h thng VoIP
c dng s dch v p ISDN giao th
H.323 d p vi ng thoi truyn th th
hiu s  h tr cho vic thit lp cuc g
thut truyn ti bn tin cho chu khiu RAS.
m :
 Ch u cuc gi : s dng mu cuc gi cho
m cui tt ni vm cu
t lp cuc gi dt
lp cuc gi cho ISDN (khuyn ngh ITU-T Q.931). Chu
cuc gi s dnh dng theo chun H.225


D06VT1 6
 Chu khin H.245 : S dng mu khi truyn ti
u khin gim cui hay gim cun
t u khi  hay b u khi m (MC).
u khic s dng bi chu khit
vu cuc gi.
Chu khim v sau :
o      c hi       ng
in.
o             gi 
(codec) gim cui.
o Quym cu
 gii quyt trong sut cuc gi.
o Ch  c hay kh 
ng truyn.

o B  : thit l    ng
thi thng nh m cui.
 Ch   u RAS : s d       
 hu n
 m cu   dng
bnh dng theo H.225.
1.2.3 
t b n ct mng VoIP da
c H.323. Theo khuyn ngh H.323, m 
bu cu



D06VT1 7

 H thng VoIP d
a> H.323
Thit b u cum cup giao din
trc tip ging. Mng VoIP s cung c n thoi
thi gian thc vm cuu cui H.323 hay khu khi
m MCU  u khin ch thng hay d liu
gia hai thit b. Mu cui H.323 ph i
PCM 64kbps theo chu tr 
G.723.1.
 ti cha mu cui H.323 bao gm
n thit b p H.225, chu khin h
thn vi mt c u cui thoi H.323 bt buc pht
khu khin h thng, H.225, giao din m 
Khu khin h thng cung c vu cu
cung cu khin cuc gu, to

   logic.
Lp H.225 thc hinh dng audio, thit l i
ng d liu khiu.


D06VT1 8

 Thit b u cui H.323
Giao din mi dng bch
hp trong mng IP s dch v TCP, UDP.
 i h tr :
 Giao thu cuc gi H.225
 Giao thu khin H.245
 n
  n t bt buc trong thit b u cui
ng g
t bu  c
   u video t ngu  truy    u
video nh i thit b hin th


b> Gateway H.323
Mm cung h tr 
tin thi gian thc giu cu ng IP vu cu
mng chuyn mch PSTN hoc mt b


D06VT1 9
n trong cu cui trong mt m 
truyc tip vi gateway. Ch ti khi cn m rng

t    t ng h
giao thm cu


 Chn ca gateway H.323
Media Gateway : MGW
Media Gateway cung c thc hin ch
n trong mng IP (RTP/UDP/IP) vn trong
m
MGW bao g
 Chuya ch   a ch   
n.
 Chuyi lung : chuyi gia m
mng SCN bao gm chuyt ting vng.
 D    nh tuy     a m   ng
SCN
 Bo mm bo tt ni vi
Gateway
 Kt cui chuyn mm tt c n cn
cn thi kt cui cuc gi chuyn m 



D06VT1 10
 Kt cui chuyn m : cha tt c i kt ni
ng chuyn m i
 
gi
 Giao din vi mng SCN : kt cui  
sang tr u khin bi ch 

 Chi gia
i, fax, d liu c liu trong
mng chuyn mc hin ch 
hu thoi, trit ting vng, trit khong l
chuyu tit t 
c hin chuyi giu DTMF trong mng SCN
p trong mng chuyn m 
u tho
 thu nh i vi
mi cuc g s dng trong viu khin cuc
gi.
 OA & M : vn logic
cung cc tip phc v u khin cuc gi
tn t qu thng.
 Chn vi h thng qung
 Giao din mng chuyn mt cui mng chuyn m

Media Gateway Controller ( MGC )
Mu khic g
n t kt nc  c gi
u khin MGW, nhu SCN t 
hiu IP t GK.
 bao gi ch
 Chn tin H.225.0
 Chn tin H.245
 Chn : thit lm nhn dng ci s dng
thit b hoc phn t mng.
 u khin GW chp nhn lung d li
mt lung d liu


D06VT1 11
 u chuyn mm tt c u cuc g
th thc hin bu cui trong m theo chu
bao gi vi mu cui
H.323 ch nhm H.245.
 Giao diu chuyn m cui giao thu chuyn
m i v ng
  qu     c ch  t ni trc tip vi
    n t MGC t   c
u khin cuc gi.
 u khin GW : bao gu khin kt ni logic, qun
i giao di t SS7 sang H.225.0)
  xa : bao g kh dng c
trung k c kh dng ca mng IP, t l nh
tuyc gi.
 u : chuy i gi u m  u mng SCN
trong phi hp hong vi SGW.
 n tin s d
t b ngoi vi.
 OA & M : vn logic
cung cc tip phc v u khin cuc gi
tn t qu thng.
 Chn vi h thng qun ng
 Giao din mng chuyn mt cui mng chuyn m
 n t c thc cao. MGC
chm qu hi
cnh s d  trit
ting vt trong GW chu s qua MGC). MG chm qu
 c th  t b phn c chuyn m  ng

t GW.

Signalling Gateway : SGW
SGW cung cu gia m h tr
chu gia m u trong mng
SCN (R2, CCS7).
 bao gi ch


D06VT1 12
 Kt nu khin cuc gi SCN
 Kt nu t mng SCN : phi hp hong v
u ca MGWC.
 Ch u : chuyi gi u mng IP vu
mng SCN khi phi hp hong vi MGWC.
 Bo mm bo mt cu t GW.
 Chn tin s dn
t b ngoi vi.
 OA & M : vn logic
cung cc tip phc v u khin cuc gi
tn t qu thng.
 Chn vi h thng qung
 Giao din mng chuyn mt cui mng chuyn m
SG s m v u trong mng PSTN
ng c chuy
dng hng IP.

c> Gatekeeper H.323
t thc
th a ch u khin truy nhp

u cung thi qum cui trong mng
m cui s dng giao th truyi Gatekeeper.
Khi khm cui mt Gatekeeper, nu muc
vi mm cu khi to mt cuc gi s dng mt
bim cu a ch E.164 hay ma ch e-mail.
N x c cuc gi ma ch m
cua ch a ch thc cm cua
ch a ch ca mt proxy hay mt gatekeeper thc hinh tuy
hiu cuc gi.
V mt thit b c lp c t ng
 p v n t m  t thit b v 
mng H.323 bao gm tp hm cuc gc qu
bi mm cui trong zone ph
Gatekeeper thc hi


D06VT1 13
 a ch : chuya ch nh danh sang ma ch IP
 u khip : gii hn truy nhp tng d
hn ch c gi
 u khi cc hiu
chp.
 Quch v tm cu
c hi
 u khin cuc gi : GK quy
u cho cuc g
 Cc gi : hn ch c gi di.
 Qu     i hn s ng truy nh ng thi t 
ng IP
 Quc gn ghi cc gc hin.

 Gatekeeper H.323

d> 
m cu
i ngh u khi  liu t 
m cu thit lp mt hi ngh n mnh m kt ni


D06VT1 14
u cui trong mt hi ngh m-i ngh
m. Mt MCU bao gm 2 phn : mt b u khim (MC) bt bu
mt b x n .
MC cung cu khin  h tr i ngh gia 3 hay nhiu
m cui tham gia mt hi ngh c hii kh i mm
cui trong mt hi ngh. MC gi mt tp kh m cu ch th 
ho s d th sa li t  gi ti
t b u cuu cui hi ngh .
MP nh m cui trong mt hi ngh 
  lm cui.
 thc hin, chuyn mch, hay x i s u
khin c x t lu hay nhiu lu
tin ph thuu ca hi ngh c h tr.
MCU.

 c ca MCU
n ca khu khim bao gm :
 B u khim : cung cp chu khin.
 B x m : thu nh i, video, data.
1.3 

1.3.1 
Giao thc khi tt giao thu
khin lp ng dm v thit l c gi gia 2 hay
nhim cun bi IETF cho hi ngh n qua


D06VT1 15
mng c chu

 trong h thng truy t kin
c kt hp vc ca I
c truyn dn d liu thi gian thc), cung cn hi
QoS, RTSP (giao thc to lung thi gian th u khii
mng PSTN, SDP (giao th   n, tuy
ng ca SIP l thut c giao
th c client-server) bao
gm tp hc gi t SIP client ti SIP server. Server x u
 li client bng mt bt vt
SIP transaction.
SIP h tr 5 ho thit l
tin :
 nh v  tr a ch,  
ng cuc gi.
 nh kh nh cp thp
nht cch v chung gim cui qua SDP.
 u mt cuc g 
 gm cui b gi
i ngh  l tr
li bm cui b g
 Thit l g gi : Nu cuc g

t lm cung thi
 tr i gia cuc gm cu
trong hi ngh -gi
 u khin cuc g c gi.
1.3.2 
SIP s d  thit l
phn t o ra mt hi ngh gia hai hay nhiu
m cung SIP s nh bi ma ch SIP duy nht.
M a ch      a ch e-  nh dng :
 a ch E.164 .
 t domaii hostname hoa ch IP.
a ch t s n thoi v  th 