  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

ng dn

 D06VT1
NHN BIN





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





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
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







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


 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



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

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


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


     


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

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,

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.

   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

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

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


 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 

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 

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