Asterisk Vietnamese Documents

Chng 1 1.1 1.2 1.3

TNG QUAN V ASTERISK

5 5 8 10 10 10 10 11 11 11 11 12 12 12 12 14 15 16 17

GII THIU ASTERISK KIN TRC ASTERISK MT S TNH NNG C BN Voicemail (hp th thoi) Call Forwarding(chuyn cuc gi) Caller ID (hin th s gi) Automated attendant (chc nng IVR) Time and Date Call Parking Remote call pickupe Privacy Manager Backlist

1.3.1 1.3.2 1.3.3 1.3.4 1.3.5 1.3.6 1.3.7 1.3.8 1.3.9 1.4

Cc ng cnh ng dng Tng i voip IP PBX Kt ni IP PBX vi PBX Kt ni gia cc server Asterisk Cc ng dng IVR, VoiceMail, in Thoi Hi Ngh Chc nng Phn phi cuc gi t ng ACD

1.4.1 1.4.2 1.4.3 1.4.4 1.4.5

Sch Asterisk http://my.opera.com/asteriskvn

Chng 2 2.1 2.2 2.3 2.4 2.5 2.6

Cc KHI NIM TRONG H THNG ASTERISK

18 18 18 19 20 20 21 21 22 23 23 23 23 24 25 26 26 26

GII THIU PBX - Private Branch Exchange VOIP - Voice Over Internet Protocol PSTN Public Switched Telephone Network TDM Time Division Multiplexing Cc hnh thc bo hiu giao tip TDM. FXO v FXS Bo hiu Analog gia u cui v tng i Bo hiu gia cc tng i

2.6.1 2.6.2 2.6.3 2.7

Bo Hiu trn mng in thoi VoIP SIP Session Initiation Prorocol Proxy server RTP v NAT IAX Inter Asterisk eXchange

2.7.1 2.7.2 2.7.3 2.7.4 2.8

Thit B VoIP Voip Phone Softphone

2.8.1 2.8.2

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2.8.3 2.8.4 2.9 2.10

Card giao tip vi PSTN ATA Analog Telephone Adaptors

27 27 28 28 29 29 31 31 31 32 33 33 34 34 35 35 36 36

Codecs QoS Quality of Service tr trt(Jitter) CI T ASTERISK

2.10.1 2.10.2 Chng 3 3.1

Ci t Asterisk Download v bung nn Ci t gi Zaptel Ci t gi libpri

3.1.1 3.1.2 3.1.3 3.2 3.3

Ci t gi Asterisk Ci t TrixBox Gii thiu DOWNLOAD V LP T TRIXBOX Cu hnh a ch IP cho card mng:

3.3.1 3.3.2 3.3.3 3.4

T Chc Th Mc ca Asterisk /etc/asterisk/

3.4.1

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3.4.2 3.4.3 3.4.4 3.4.5 3.4.6 3.4.7 3.5

/usr/lib/asterisk/modules/ /var/lib/asterisk /var/spool/asterisk/ /var/run/ /var/log/asterisk/ /var/log/asterisk/cdr-csv

36 37 38 39 39 40 40 42 42 42 43 44 44 45 46 46 46 47

Mt s lnh thao tc trn h thng asterisk CU HNH H THNG ASTERISK

Chng 4 4.1 4.2 4.3

GII THIU Tp Tin cu hnh Cc kiu nh hng trong tp cu hnh Simple Group Option inheritance Complex Entity

4.3.1 4.3.2 4.3.3 4.4

Cu hnh giao tip vi mng PSTN Ng cnh kt ni Lp t card TDM01B v cu hnh.

4.4.1 4.4.2 4.5

Cu hnh in thoi IP SIP phone.

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4.5.1 4.5.2 4.6

Phn khai bo Chung Khai bo knh SIP

48 49 50 51 52 53 53 55

Gii Thiu DialPlan Extentions Priorities Th t thc hin Aplications Cc hm ng dng Contexts - Ng cnh

4.6.1 4.6.2 4.6.3 4.6.4 4.7

Ng cnh thc hnh ng dng

4.7.1

Bc 1: Cu hnh cho hai sip phone X-lite 8051 v 8052 bng 56

cch cu hnh trn file sip.conf nh sau: 4.7.2 4.7.3 8052 4.8

Bc 2: Cu hnh softphone x-lite pha client cho my 8051 57 Bc 3 : Lp li bc hai khai bo my in thoi softphone 58

To diaplan. Thc hin mt v d c bn. Cc ng dng dial(), background() v goto().

58 58 59

4.8.1 4.8.2

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1

TNG QUAN V ASTERISK

1

GII THIU ASTERISK

Hn hnh cho mng n vi th gii diu k ca Astetisk. Asterisk em n cho ngi s dng tt c cc tnh nng v ng dng ca h thng tng i PBX v cung cp nhiu tnh nng m tng i PBX thng thng khng c c, l s kt hp gia chuyn mch VOIP v chuyn mch TDM, l kh nng m rng p ng nhu cu cho tng ng dng Asterisk l h thng chuyn mch mm, l phn mm ngun m c vit bng ngn ng C chy trn h iu hnh linux thc hin tt c cc tnh nng ca tng i PBX v hn th na. Asterisk ra i vo nm 1999 bi mt chng trai sinhTc Gi L Quc Ton

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nm 1977 tn l Mark Spencer, Anh ta vit phn mm ny ban u khng ngoi mc ch h tr cho cng ty ca mnh trong vic lin lc m thoi h tr cng ng ngi s dng v pht trin Linux. Asterisk l mt PBX v nhiu hn th. Asterisk l mt phn mm mang tnh cch mng, tin cy, m ngun m v min ph m bin mt PC r tin thng thng chy Linux thnh mt h thng in thoi doanh nghip mnh m. Asterisk l mt b cng c m ngun m cho cc ng dng thoi v l mt server x l cuc gi y chc nng. Asterisk l mt nn tng tch hp in thoi vi tnh ho kin trc m. Nhiu h thng Asterisk c ci t thnh cng trn khp th gii. Cng ngh Asterisk ang phc v cho nhiu doanh nghip. Hin nay Asterisk trn pht trin nhanh c rt nhiu doanh nghip trin khai ng dng cho cng ty ca mnh. y l xu th tt yu ca ngi s dng in thoi, v cc cng ty u c mng my tnh v cn lin lc vi nhau trong cng vic gia cc phng ban hoc chi nhnh v cn mt chi ph thp thm ch khng phi tn chi ph khi thc hin cc cuc gi trn mng ni b ca cng ty. Khng gi gn thng tin lin lc trong cng ty m cc ng dng giao tip vi mng PSTN hoc mng VOIP (nh voice777) cho php gi ra bt c s in thoi no c trn mng PSTN. Ngoi ra vic tch hp vo cc ng dng nh CRM v h thng Outlook lm cho kh nng ng dng ca Asterisk linh hot hn p ng nhu cu cn thit cho ngi s dng in thoi. Asterisk thot u c pht trin trn GNU/Linux nn x86 (Intel), nhng gi y n cng c th bin dch v chy trn OpenBSD, FreeBSD v Mac OS X v Microsoft Windows.

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S Tng qut

Asterisk l h thng chuyn mch tch hp va l cng ngh truyn thng TDM va l chguyn mch voip. Hnh trn cng cho thy kh nng giao tip ca h thng. Giao tip vi in thoi analog thng thng, giao tip vi thit b in thoi voip, ngoi ra cn c th giao tip vi mng PSTN v cc nh cung cp voip khc.2 KIN TRC ASTERISK

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V c bn kin trc ca Asterisk l s kt hp gia nn tng cng ngh in thoi v ng dng in thoi. cng ngh in thoi cho VOIP nh SIP, H323, IAX, MGCP... cc cng ngh in thoi cho h thng chuyn mch mch TDM nh T1, E1, ISDN v cc giao tip ng truyn thoi Analog. Cc ng dng thoi nh chuyn mch cuc gi, tng tc thoi, caller ID, voicemail, chuyn cuc gi Asterisk c mt s chc nng chnh ng vai tr quan trng trong h thng chuyn mch cuc gi. Khi khi ng h thng Asterisk th chc nng Dynamic Module Loader thc hin np driver ca thit b, np cc knh giao tip, cc format, codec v cc ng dng lin quan, ng thi cc hm API cng c lin kt np vo h thng.

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Sau h thng PBX Switching Core ca Asterisk chuyn sang trng thi sn sng hot ng chuyn mch cuc gi, cc cuc gi c chuyn mch tu vo k hoch quay s (Dialplan) c thc hin cu hnh trong file extension.conf. Chc nng Application Launchar rung chung thu bao, quay s, nh hng cuc gi, kt ni vi hp th thoi Scheduler and I/O Manager m nhim cc ng dng nng cao, cc chc nng c pht trin bi cng ng pht trin asterisk. Codec Translator xc nhn cc knh nn d liu ng vi cc chun khc nhau c th kt hp lin lc c vi nhau. Tt c cc cuc gi nh hng qua h thng Asterisk u thng qua cc giao tip nh SIP, Zaptel, IAX. Nn h thng Asterisk phi m trch nhim v lin kt cc giao tip khc nhau x l cuc gi.H thng cng bao gm 4 chc nng API chnh:

Codec translator API: cc hm m nhim thc thi v gii nn cc chun khc nhau nh G711, GMS, G729 Asterisk Channel API : Giao tip vi cc knh lin lc khc nhau, y l u mi cho vic kt ni cc cuc gi tng thch vi nhiu chun khc nhau nh SIP, IAX, H323. Zaptel Asterisk file format API : Asterisk tng thch vi vic x l cc loi file c nh dng khc nhau nh Mp3, wav, gsm Asterisk Aplication API : Bao gm tt c cc ng dng c thc thi trong h thng Asterisk nh voicemail, callerID

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Ngoi ra, Asterisk cn c th vin Asterisk Gateway Interface (AGI, tng t nh CGI) - c ch kch hot ng dng bn ngoi, cho php vit kch bn phc tp vi mt s ngn ng nh PHP hay Perl. Ni chung, kh nng vit cc ng dng ty bin rt ln.3 MT S TNH NNG C BN

Asterisk c rt nhiu tnh nng c gii thiu trn nhng hiu r ht tt c cc tnh nng trn tht s l thch thc i vi chng ta. Trong phn ny chng ti s gii thiu mt s tnh nng vi cc ng dng c th hiu hn v h thng asterisk.1 Voicemail (hp th thoi)

y l tnh nng cho php h thng nhn cc thng ip tin nhn thoi, mi my in thoi c khai bo trong h thng Asterisk cho php khai bo thm chc nng hp th thoi. Mi khi s in thoi bn hay ngoi vng ph sng th h thng asterisk nh hng trc tip cc cuc gi n hp th thoi tng ng khai bo trc. Voicemail cung cp cho ngi s dng nhiu tnh nng la chn nh : password xc nhn khi truy cp vo hp th thoi, gi mail bo khi c thng ip mi.2 Call Forwarding(chuyn cuc gi)

Khi khng nh, hoc i cng tc m ngi s dng khng mun b l tt c cc cuc gi n th hy ngh ngay n tnh nng chuyn cuc gi. y l tnh nng thng c s dng trong h thng Asterisk. Chc nng cho php chuyn mt cuc gi n mt hay nhiu s my in thoi c nh trc.

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Mt s trng hp cn chuyn cuc gi nh : Chuyn cuc gi khi bn, chuyn cuc gi khi khng tr li, chuyn cuc gi tc thi, chuyn cuc gi vi thi gian nh trc.3 Caller ID (hin th s gi)

Chc nng ny rt hu dng khi mt ai gi n v ta mun bit chnh xc l gi t u v trong mt s trng hp bit chc h l ai. Ngoi ra Caller ID cn l chc nng cho php chng ta xc nhn s thu bao gi n c ngha l da vo caller ID chng ta c tip nhn hay khng tip nhn cuc gi t pha h thng Asterisk. Ngn mt s cuc gi ngoi mun.4 Automated attendant (chc nng IVR)

Chc nng tng tc thoi c rt nhiu ng dng trong thc t, khi gi in thoi n mt c quan hay x nghip thu bao thng nghe thng ip nh Xin cho mng bn gi n cng ty chng Ti hy nhn phm 1 gp phng kinh doanh, phm 2 gp phng k thut sau tu vo s tng tc ca thu bao gi n, h thng Asteisk s nh hng cuc gi theo mong mun. Khi mun xem im thi, mun bit tin cc in thoi ca thu bao, mun bit t gi la hin nay nh th no, hay kt qu s s tt cc nhng mong mun trn u c th thc hin qua chc nng tng tc thoi.5 Time and Date

Vo tng thi gian c th cuc gi s nh hng n mt s in thoi hay mt chc nng c th khc, v d trong cng ty gim c mun ch cho php nhn vin s dng my in thoi trong gi hnh chnh cn ngoi gi th s hn ch hay khng cho php gi ra bn ngoi.

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6

Call Parking

y l chc nng chuyn cuc gi c qun l. C mt s in thoi trung gian v hai thu bao c th gp nhau khi thu bao c gi nhn vo s in thoi m thu bao ch gi ang ch trn v t y c th gp nhau v m thoi.7 Remote call pickupe

y l tnh nng cho php chng ta t my in thoi ny c th nhn cuc gi t my in thoi khc ang rung chung

8

Privacy Manager

Khi mt ngi ch doanh nghip trin khai Asterisk cho h thng in thoi ca cng ty mnh nhng li khng mun nhn vin trong cng ty gi i ra ngoi tr chuyn vi bn b, khi Asterisk cung cp 1 tnh nng tin dng l ch cho php s in thoi c lp trnh c php gi n nhng s my c nh no thi, cn nhng s khng c trong danh sch nh sn s khng thc hin cuc gi c9 Backlist

Backlist cng ging nh Privacy Manager nhng c mt s khc bit l nhng my in thoi nm trong danh sch s khng gi c n my ca mnh (s dng trong tnh trng hay b quy ri in thoi) V cn rt nhiu tnh nng na m h thng asterisk c th cung cp cho ngi s dng, trn y ch l mt s tnh nng thng c s dng m thi, bit nhiu hn chi tit hn cc tnh nng cn li xin hy tham quan websitewww.asterisk.org. 4 Cc ng cnh ng dng

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Asterisk thc hin rt nhiu ng cnh ng dng khc nhau tu vo nhu cu s dng, di dy l nhng ng cnh ng dng thng c s dng trong thc t trin khai h thng asterisk.1 Tng i voip IP PBX

IP BPX

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y l h thng chuyn mch voip c xy dng phc v cc cng ty c nhu cu thc hin trn nn tng mng ni b trin khai. Thay v lp t mt h thng PBX cho nhu cu lin lc ni b th nn lp t h thng voip iu ny s lm gim chi ph ng k. H thng c th lin lc vi mng PSTN qua giao tip TDM.2 Kt ni IP PBX vi PBX

Kt ni IP PBX vi PBX

Mt ng cnh t ra y l hin ti Cng ty trang b h thng PBX by gi cn trang b thm p ng nhu cu lin lc trong cng ty sao cho vi chi ph thp nht, gii php thc hin l trang b h thng asterisk v kt ni vi hTc Gi L Quc Ton

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thng PBX ang tn ti qua lung E1. Ngoi ra tng kh nng lin lc vi mng PSTN v VOIP khc, Cng Ty c th thc hin kt ni vi nh cung cp dch v voip.3 Kt ni gia cc server Asterisk

Kt ni gia cc server asterisk

Phng php trn ng dng rt hiu qu cho cc cng ty nm ri rc cc v tr a l khc nhau nhm gim chi ph ng di. V d Cng ty M c tr s t ti nc M v cc Chi nhnh t ti Vit Nam vi cc a im Thnh ph H Ch Minh v H Ni. Thng qua mng WAN ca Cng Ty cc cuc gi ni b gia cc

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v tr khc nhau s lm gim chi ph ng k. Ng cnh ny v mt php lut khng cho cuc gi t M vo Vit Nam.4 Cc ng dng IVR, VoiceMail, in Thoi Hi Ngh

Trin khai server IVR, VoiceMail, Hi Thoi

ng dng thc hin cc server kt ni vi h thng PSTN hay tng i PBX trin khai cc ng dng nh tng tc thoi IVR. Mt v d cho ng dng tng tc thoi l cho bit kt qu s s hay kim tra cc cuc gi ging dch v 19001260 vy. ng dng VoiceMail thu nhn nhng tin nhn thoi t pha thu bao ging nh chc nng hp th thoi ca Bu in Thnh ph trin khai. CnTc Gi L Quc Ton

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chc nng in thoi hi ngh thit lp cho nhiu my in thoi cng ni chuyn vi nhau.5 Chc nng Phn phi cuc gi t ng ACD

Phn phi cuc gi vi hng i

ACD(Automatic Call Distribution): Phn phi cuc gi t ng. y l chc nng ng dng cho nhu cu chm sc khch hng hay nhn phn hi t pha khch hng.

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Cng ty c kh nng tip nhn cng mt lc 10 cuc gi nh th cuc gi th 11 gi n th h thng gii quyt nh th no?. Bnh thng th s nghe tn hiu bn nhng vi chc nng phn phi cuc gi s a thu bao vo hng i ch tr li, trong khi ch tr li cuc gi thu bao c th nghe nhng bi ht hay do asterisk cung cp, trong lc ny nu 1 trong mi s in thoi tr v trng thi ri th cuc gi ang ch s c tr li. Ging nh chc nng ca dch v 1080 hay 116 ca Bu in Thnh Ph vy.

2

CC KHI NIM TRONG H THNG ASTERISK

1

GII THIU

Trong chng ny s gii thch r cc khi nim c bn lin quan n h thng asterisk, cung cp nhng kin thc nn tng, nhng khi nim cn thit thit k trin khai xy dng h thng in thoi vi Asterisk.2 PBX - Private Branch Exchange

PBX hay cn gi l PABX - Private Automatic Branch Exchange l h thng tng i ni b c t ti nh thu bao, t Automatic y mun ni n l h thng tng i in t t ng nhng hin nay a s l tng i PBX in t t ng nn t trn thc s khng cn cn thit na. PBX vi mc tiu chia s nhiu thu bao ni b gi ra th gii bn ngoi thng qua mt vi ng trung k hay ni mt cch khc PBX l h thng trung chuyn gia cc ng dy in thoi bn ngoi t cng ty in thoi v my in thoi ni b trong tng i PBX. V th nn s lng my in thoi ni b lun nhiu hn s ng dy ni n PBX t bn ngoi.

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PBX thc hin chuyn mch cuc gi cc my in thoi ni b vi nhau v vi cc my in thoi bn ngoi thng qua ng trung k. ng thi thc hin chuyn mch cc cuc gi in thoi t bn ngoi vo cc my in thoi ni b. Ngoi vic chuyn mch cuc gi PBX cung cp nhiu tnh nng s dng cho nhiu mc ch khc nhau ca khch hng m bn thn cc ng dy in thoi t cng ty in thoi kt ni n khng th thc hin c, cc tnh nng nh tng tc thoi(IVR), Voicemail, phn phi cuc gi t ng(ADC) Hin nay vi vic pht trin mnh m ca cng ngh VoIP, chng ta cn c thm thut ng IP PBX. y l h thng chuyn mch PBX vi cng ngh Voip.3 VOIP - Voice Over Internet Protocol

Voice over Internet Protocol (VoIP) l mt cng ngh cho php truyn thoi s dng giao thc mng IP, trn c s h tng sn c ca mng internet. Voip l mt trong nhng cng ngh vin thng ang c quan tm nht hin nay khng ch i vi nh khai thc, cc nh sn xut m cn c vi ngi s dng dch v. Voip c th va thc hin mi loi cuc gi nh trn mng in thoi knh truyn thng (PSTN) ng thi truyn d liu trn c s mng truyn d liu. Do cc u im v gi thnh dch v v s tch hp nhiu loi hnh dch v nn voip hin nay c trin khai mt cc rng ri. Dch v in thoi voip l dch v ng dng giao thc IP, nguyn tc ca VoIP bao gm vic s ho tn hiu ting ni, thc hin vic nn tn hiu s, chia nh cc gi nu cn v truyn gi tin ny qua mng, ti ni nhn cc gi tin ny c rp li theo ng th t ca bn tin, gii m tn hiu tng t phc hi li ting ni ban u.

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Cc cuc gi trong VoIP da trn c s s dng kt hp c chuyn mch knh v chuyn mch gi. Trong mi loi chuyn mch u c u, nhc im ring ca n. Trong k thut chuyn mch knh ginh ring cho mt knh truyn gia hai thit b u cui thng qua cc node chuyn mch trung gian. Trong chuyn mch knh tc truyn dn lun lun c nh(ngha l bng thng khng i) , vi mng in thoi PSTN tc ny l 64kbps, truyn dn trong chuyn mch knh c tr nh. Trong chuyn mch gi cc bn tin c chia thnh cc gi nh gi l cc gi, nguyn tc hot ng ca n l s dng h thng lu tr v chuyn tip cc gi tin trong nt mng. i vi chuyn mch gi khng tn ti khi nim knh ring, bng thng khng c nh c ngha l c th thay i tc truyn, k thut chuyn mch gi phi chu tr ln v trong chuyn mch gi khng quy nh thi gian cho mi gi d liu ti ch, mi gi c th i bng nhiu con ng khc nhau ti ch, chuyn mch gi thch hp cho vic truyn d liu v trong mng truyn d liu khng i hi v thi gian thc nh thoi, s dng u im ca mi loi chuyn mch trn th trong voip kt hp s dng c hai loi chuyn mch knh v chuyn mch gi.4 PSTN Public Switched Telephone Network

PSTN l mng chuyn mch in thoi cng cng hay ni cch khc l mng kt ni tt c cc h thng tng i chuyn mch-mch. hiu r hn hy xem xt mng PSTN vi mng Internet v kha cnh chuyn thoi trn . Chuyn mch mch mun thc hin cuc gi gia hai thu bao th h thng phi ginh ring mt knh truyn 64kbps chuyn ti tn hiu thoi trn , Cn cuc gi in thoi trn mng Internet th tn hiu thoi c ng gi v chuyn i trn cng knh truyn vi nhiu dch v khc. V l cht lng cuc gi trn mng PSTN bao gi cng tt hn trn mng Internet nhng iTc Gi L Quc Ton

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li chi ph li c hn rt nhiu, c bit l cc cuc gi quc t, nn phi cn cn nhc k khi s dng. PSTN c pht trin trn chun ITU(International Telecommunication Union) cn mng Internet c pht trin trn chun IETF(Internet Engineering Task Force) c hai mng trn u s dng a ch nh tuyn cuc gi, PSTN s dng cc con s in thoi chuyn mch cuc gi gia cc tng i in thoi trong khi trn mng Internet, a ch IP s c s dng nh tuyn cc gi thoi.5 TDM Time Division Multiplexing

L k thut ghp knh phn chia thi gian nhiu tn hiu c th truyn ng thi trn mt ng truyn, TDM c s dng chuyn thoi trong h thng mng PSTN. C hai chun ghp knh TDM c bn l E1 vi 30 knh thoi trn mt khung tc 2Mbps v T1 vi 24 knh thoi tc 1.5Mbps.

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Hnh Minh ha ghp knh phn chia theo thi gian 6 1 Cc hnh thc bo hiu giao tip TDM. FXO v FXS

FXO (Foreign Exchange Office) l thit b nhn tn hiu t tng i gi n nh dng chung, tn hiu nhc gc my, tn hiu mi quay s, gi v nhn tn hiu thoi FXO ging nh my Fax hay modem dial-up 56k vy. Dng kt ni vi ng dy in thoi. FXS (Foreign Exchange Station) l thit b ti ni cung cp ng dy in thoi, thit b FXS s cung cp tn hiu mi quay s(dialtone), dng chung, hi m chung(ring tone). Trong ng dy Analog FXS cung cp dng chung v in p cho in thoi hot ng v d FXS cung cp in p -48VDC n my in thoi

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Analog trong sut thi gian m thoi v cung cp 90VAC(20hz) pht in p rung chung. Thit b FXS pht cn thit b FXO nhn. Card TDM s dng trong h thng asterisk thng tch hp va thit b FXO va l thit b FXS(Ging b ATA) FXO kt ni vi ng dy in thoi cn FXS dng kt ni vi my in thoi analog thng thng dng chuyn mch cuc gi TDM qua h thng asterisk(Xem thm trong phn cu hnh cho knh TDM). Tm li cn nm: FXS c kt ni vi FXO ging vi ng dy in thoi ni vi my in thoi. FXS cung cp ngun cho in thoi FXO(in thoi Analog)

Hnh a) My in thoi vai tr FXO kt ni vi FXS(PSTN), Hnh b) PBX kt ni vi FXO v FXS, Hnh c) ATA ng vai tr nh FXS kt ni vi my in thoi vai tr FXO.

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2

Bo hiu Analog gia u cui v tng i

Khi chng ta nhc my in thoi gi th nghe tn hiu mi quay s, khi cuc gi gi u bn kia b bn th chng ta nghe tn hiu bn(busy tone) cc loi tn hiu nh vy gi l cc tn hiu bo hiu analog. Cc tn hiu nh: Mi quay s, tn hiu bn, rung chung, trng thi nhc gc my. Cc loi tn hiu trn c trao i gia thit b FXO v FXS. C nhiu phng thc bo hiu khc nhau ng vi tng ni s dng, v th ti ni kt ni vi ng dy in thoi cn xem xt h ang s dng phng thc bo hiu g, t chng ta khai thc loi tn hiu bo hiu cho thch hp, cc phng thc bo hiu nh Loop Start, Ground Start. Mt minh ha cho vic s dng sai phng thc bo hiu l khi chng ta khai bo phng thc bo hiu gia h thng Asterisk v ng dy in thoi khc nhau th dn n Asterisk s khng nhn bit c tn hiu gc my, iu ny s lm cho asterisk khng bo gi gii ta c cuc gi thc hin cuc gi mi.3 Bo hiu gia cc tng i

SS7 h thng bo hiu s 7 c pht trin bi AT&T v ITU l h thng bo hiu chuyn cc cuc gi gia cc tng i trong mng PSTN. Trong h thng bo hiu s 7 tn hiu chuyn ti trn ng trung k kt ni gia hai tng i gm c hai mch ring, mt cho thoi v mt cho bo hiu, nh vy thoi v bo hiu c th chuyn trn hai knh vt l khc nhau.7 1 Bo Hiu trn mng in thoi VoIP SIP Session Initiation Prorocol

Sip l giao thc Internet dnh cho bo hiu VoIP c pht trin bi IETF cung cp vi chc nng ging h thng bo hiu s 7 nhng da trn nn IP. Mt chc nng ging bo hiu s 7 l bo hiu v thoi chuyn ti trn hai knhTc Gi L Quc Ton

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ring. Giao thc SIP thc hin chc nng thit lp v bo hiu cuc gi, khi ni n bo hiu cuc gi l ch nh cc tn hiu bo hiu nh: tn hiu mi quay s, tn hiu bn2 Proxy server

Mc du hai thit b SIP c th lin lc trc tip vi nhau khi to cuc gi nhng trong giao thc SIP cn c chc nng Proxy linh hot hn trong thit lp cuc gi. Proxy Server s lm nhim v ghi nhn tt c cc s in thoi c pha client ng k n qua bn tin Registration. Khi mt client khc thc hin cuc gi th thc s Client khng bit s in thoi cn gi ang u nn thng qua Proxy server tm kim thit lp cuc gi.

+

Hnh ng k t Client n SIP Proxy, Vi Giao thc SIP ng bo hiu v thoi ring.3 RTP v NAT

Cc cuc gi trn Internet vi giao thc SIP c chia thnh cc gi thoi v c chuyn qua giao thc RTP(Real Time Protocol) . RTP l giao thc khng ch thc hin chuyn cc gi thoi qua Internet m cn c c video na. Mt cuc gi

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thng thng c hai hng thng tin l nhn v pht, RTP lm vic chuyn cc gi d liu thoi cng trn hai hng. NAT Network Address Translators l mt tr ngi ln trong giao thc RTP. Mng s dng NAT l mt mng chia s nhiu a ch IP ni b vi mt a ch IP Cng cng kt ni vi th gii bn ngoi. NAT dng chia s nhiu my tnh trong mng LAN ni b s dng c Internet, nhng cng chnh v th m cc my tnh ni b gp kh khn trong vic thc hin cuc gi VoIP qua Internet. chnh l vn tr ngi khi truyn thoi qua giao thc RTP.

Hnh Minh ha hot ng ca NAT Trong Giao thc RTP nh chng ta bit l thoi c chuyn trn hai ng khc nhau l ng pht v ng thu, Vn NAT nm ch tn hiu thoi t bn ngoi vo bn trong qua giao thc RTP khng thc hin c cn chiu ngc li th thc hin tt. Hay ni cch khc vn NAT lm cho cc cuc gi t

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Internet m thoi vo cc my ni b qua NAT th khng nghe c, cn trong trng hp cc cuc gi t cc my ni b ra cc my internet th nghe tt. Vn NAT trn c gii quyt trong Asterisk bng vic khai bo thng s NAT=yes trong cu hnh knh giao thc SIP.4 IAX Inter Asterisk eXchange

IAX l giao thc bo hiu Voip c pht trin bi tc gi ca phn mm Asterisk khc phc nhng hn ch trong giao thc SIP. Khng ging nh giao thc SIP chuyn ti thoi v bo hiu trn hai knh khc nhau (out of band), IAX chuyn ti thoi v bo hiu trn cng mt knh(in band). IAX gii quyt c vn NAT cp trn phn giao thc SIP. Mc khc IAX l giao thc ti u trong vic s dng bng thng, cho php nhiu gi d liu thoi trn cng mt IP header, c ch chuyn ti nhiu cuc gi trn cng mt gi IP c gi l trung k(Trunk). C th gii thch thm c ch trung k nh sau: Gi s Ti cn gi 5 bc th ti ngi bn ca Ti, Ti s c hai hnh thc thc hin, th nht l mi bc th Ti b vo mt phong b vy tng cng ti phi s dng 5 phong b gi i 5 bc th, Cch th hai l Ti b 5 bc th vo 1 phong b v gi i vy tng cng Ti ch tn 1 phong b, Qua phn tch trn r rng vic 5 bc th vo mt phong b s tit kim hn so vi 5 bc th vi 5 phong b. C ch trn cng ging nh nhiu cuc gi c ng thnh gi v chuyn i trn ng trung k. Tm li: IAX l giao thc dnh cho VoIP mi nht cho n thi im ny vi nhiu u im hp dn nh: + Ti thiu s dng bng thng. + Trong sut vi NAT. + Hiu qu vi c ch trung k.

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8 1

Thit B VoIP Voip Phone

y l thit b phn cng kt ni vi mng VoIP ging nh my in thoi bn thng thng nhng dnh cho VoIP, cn phi thc hin cu hnh trc khi s dng. Lu mt s tnh nng khi thc hin mua thit b in thoi VoIP: + Low bandwidth : h tr Codec no, G729 l tt nht hin nay. + Web Interface : Phi c giao tip thit lp cu hnh thn thin d s dng. + Audio Interface : C speaker phone hay khng? Gi thnh ca in thoi voip IP c hn in thoi thng thng, gi khong trn di 100$ mt ci.

Hnh My in Thoi VoIP

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2

Softphone

L mt phn mm c ci trn my tnh thc hin tt c cc chc nng ging nh thit b in thoi Voip, cn lu khi s dng softphone l my tnh phi c card m thanh, headphone v firewall khng b kha. S dng softphone vi h thng Asterisk nn dng softphone vi cng ngh giao thc mi dnh cho Asterisk l IAX.

Hnh in Thoi Softphone 3 Card giao tip vi PSTN

Mun cho php cc my in thoi ni b trong h thng Asterisk kt ni v thc hin cuc gi vi mng PSTN chng ta cn phi c thit b phn cng tng thch. Thit b phn cng s dng cho h thng Asterisk do chnh tc gi lp cng ty Digium phn phi, y cng chnh l tng ln trong vic phn phi phn mm Asterisk l h thng ngun m s dng min ph. Thit b phn cng thng k hiu bt u bng cm t TDMxyB trong x l s lng port FXS, y l s lng port FXO gi tr ti a ca x v y l 4, v d card TDM22B c ngha l c 2 fort FXS v 2 port FXO.

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Hnh Card TDM22B gm 4 port 2 FXS v 2 FXO 4 ATA Analog Telephone Adaptors

ATA l thit b kt ni vi in thoi Analog thng thng n mng VoIP, mt thit b ATA gm c hai loi port: RJ-11 kt ni vi my in thoi analog thng thng cn RJ-45 kt ni vi mng VoIP. ATA thc s l thit b FXS chuyn i tn hiu Analog sang tn hiu s s dng cho mng VoIP, tn dng my in thoi Analog nn trang b thit b ATA thay v phi trang b in thoi VoIP. Thit b ATA s dng vi giao thc IAX c Digium phn phi l thit b ATA c s dng rng ri vi Asterisk c tn gi l IAXy.

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Hnh Thit b ATA 9 Codecs

Thut Ton codecs(Compressor/De-compressor) l mt tp cc quy lut c s dng chuyn i cc tn hiu thoi dng Analog sang tn hiu s v ngc li. C nhiu thut ton codec thc hin chuyn i tn hiu analog sang tn hiu s dng nh phn (0,1) nh G711, GSM, G729ng vi mi thut ton c nhng u im ring, c bit l vic ti u s dng bng thng trn ng truyn. Mc tiu cui cng l cc thut ton a ra phi m bo cht lng cuc gi nht v tit kim bng thng nht. G729 l thut ton codec tt nht hin nay trong h thng VoIP. Vi h thng Asterisk s dng thut ton ny cn phi mua bn quyn s dng v y l codec khng min ph s dng.10 QoS Quality of Service

Cc yu t nh hng n cht lng ca dch v, i vi VoIP l cc yu nh hng n cht lng tn hiu thoi.1Tc Gi L Quc Ton

tr

32


Thoi l dch v mang tnh thi gian thc rt cao v th tr l yu t nh hng rt ln n cht lng dch v. Tr c nh ngha l khong thi gian tnh t lc tn hiu thoi i t ming ngi ni ti tai ngi nghe. Tr l yu t khng th trnh khi, tr i vi mng in thoi truyn thng (mng PSTN) khong t 50ms n 70ms, theo khin ngh ca ITU-T m bo cht lng cho h thng VoIP th tr t u pht ti u thu hoc ngc li khng c vt qu 150ms, khi m tr vt qu 400ms n 500ms th khng th chp nhn c. Cc nguyn nhn gy ra tr bao gm : Tr trn mng li, tr trn b m ha gii m, tr trong qu trnh ng gi, tr b m, tr x l ting ni2 trt(Jitter)

Nguyn nhn gy ra trt l gi tn hiu thoi trong qu trnh truyn t ngun n ch s gp phi nhng iu kin khc nhau trn mng li do thng n ch vi nhng khong tr khc nhau. y l tnh khng ng nht ca tr. Mt nguyn nhn khc ca trt i vi ng dng PC to PC l do vic s dng h iu hnh phi thi gian thc, cc gi tin thoi phi i h iu hnh x l trong nhng khong thi gian khc nhau khi m h iu hnh ang phi x l i vi cc ng dng khc.

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Hnh Nguyn nhn xy ra trt

loi b tnh khng ng nht ca tr, ngi ta thit k cc b m tr (Jitter Buffer) ti ni n ca cc gi tin, cc gi tin n vi cc khong cch khc nhau v thi gian c lu ti b m ri pht khi b m vi khong tr nhTc Gi L Quc Ton

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nhau. Khi b m c kch thc cng ln th kh nng loi b tnh khng ng nht cng ln, tuy nhin vic s dng b m s gy ra hin tng tr trong ng dng thoi, do cn c bi ton cn i gia tr v trt. Ngoi 2 nguyn nhn trn cn mt s nguyn nhn na nh hng n cht lng thoi nh mt gi, gii hn bng thng, ting vng.

3

CI T ASTERISK

1 1

Ci t Asterisk Download v bung nn

ci t Asterisk, u tin chng ta cn phi ci t h iu hnh linux trn my tnh ca mnh. C th ci h iu hnh Linux Fedora , CentOS, Redhat, hoc Debian. Cc gi phn mm ph thuc phi c trong h iu hnh Linux trc khi ci Asterisk bao gm: bison gcc kernel-source libtermcap-devel ncurses-devel openssl096b openssl-devel

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Sau khi hon tt cc bc trn chng ta tin hnh download phn mm asterisk vi phin bn mi nht. # cd /usr/src # wget ftp://ftp.digium.com/pub/asterisk/asterisk-1.4.0.tar.gz # wget ftp://ftp.digium.com/pub/asterisk/asterisk-addons-1.4.0.tar.gz # wget ftp://ftp.digium.com/pub/asterisk/asterisk-sounds-1.4.0.tar.gz # wget http://ftp.digium.com/pub/zaptel/zaptel-1.4.0.tar.gz # wget http://ftp.digium.com/pub/libpri/libpri-1.4.0.tar.gz

Vic download c th nhanh hay chm ty vo tc trn ng internet , sau khi download hon thnh chng ta tin hnh bung nn cc gi ra th mc ch nh # tar xzvf asterisk-1.4.0.tar.gz # tar xzvf asterisk-addons-1.4.0.tar.gz # tar xzvf asterisk-sounds-1.4.0.tar.gz # tar xzvf zaptel-1.4.0.tar.gz # tar xzvf libpri-1.4.0.tar.gz Gii nn xong chng ta nh thc hin lnh#ln s /usr/src/asterisk-1.4.0 /usr/src/asterisk

lnh ny bo m gi

addons c bin dch ng

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By gi ti phn chng ta bin dch cc gi gii nn trn, trc tin l gi zaptel k n l libpri sau cng l gi Asterisk.2 Ci t gi Zaptel

Gi zaptel s cha ti th mc /usr/src/zaptel. nh lnh nh di y ci t: # cd /usr/src/zaptel # make clean; make install Lnh ny thc hin khong 2 pht, ty vo tc my tnh ci t. sau khi ci t xong s tr li du nhc lnh v hin th mt lot cc thng bo trong c mt s bn tin li m ch yu l yu cu ci t cc gi ph thuc lit k trn, nu cc gi trn cha c ci t. Gi zaptel ny cha cc driver cho cc phn cng kt giao tip vi asterisk do Digium phn phi, v mt s th vin cho vic c thc hin giao tip vi phn cng hay khng. Asterisk c th chy cng vi khi ng ca my tnh chng ta cn thc hin lnh # make config Lnh ny s to ra script chn module zaptel vo kernel v chy ztconfig vo lc khi ng my. Trong Redhat script ny s c chp vo /etc/init.d chy mc 3.3 Ci t gi libpri

K n chng ta bin dch gi libpri ti th mc /usr/src/libpri bng lnh:

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# cd /usr/src/libpri # make clean; make install

on bin dch ny kh nhau khong 1 pht, sau khi thc hin xong s tr v du nhc lnh. Th vin libpri cung cp cc driver cho cc card giao tip trung k PRI v mt s phn cng khc. Ngay c Asterisk khng giao tip vi card PRI no chng ta cng nn ci t gi ny bi mt s module ca Asterisk yu cu th vin ny.2 Ci t gi Asterisk

Sau khi thc hin ci t cc gi ph thuc by gi chng ta thc s ci t Asterisk. Phn ny cha trong th mc /usr/src/asterisk nn thc hin g lnh nh sau:# cd /usr/src/asterisk # make clean; make install

Kt thc vic thc hin ci t chng ta s c mt h thng PBX hon chnh v cc tnh nng trn . Ti thi im ny chng ta s tin hnh thc hin cu hnh h thng p ng vi tng nhu cu ng dng. hiu hn v cch cu hnh chng ta s xem cc tp tin cu hnh mu bng lnh sau:# make samples

Cc tp tin cu hnh mu c t trong th mc /etc/asterisk ngoi tr tp tin zaptel.conf c t trong th mc /etc/ Asterisk khi ng mi khi m my tnh chng ta dng lnh:

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# make config

3 1

Ci t TrixBox Gii thiu

TRIXBOX c pht trin t nhn ca ng dng Asterisk, c tng hp t mt s thnh phn chnh c pht trin bi cng ng pht trin ngun m Asterisk di bn quyn GPL. Trixbox bao gm nhng thnh phn chnh cho vic cu hnh ng dng, thng k tnh trng hot ng h thng, lu tr d phng, v nhn l h iu hnh CentOS mt phin bn khc ca Redhat, tt c kt hp vi nhau to thnh mt gi hon chnh. Khi ci gi ny vo my tnh th c th s dng nh mt tng i PBX. Cc thnh phn chnh trong gi TRIXBOX l Asterisk PBX: Thnh phn chnh ca h thng Trixbox CentOS: Mt phin bn Linux khc ca Redhat hon ton min ph s dng. L nhn chnh cho Trixbox. SugarCRM: H thng quan h khch hng CRM A2Billing L thnh phn dnh cho vic xy dng h thng in thoi tr trc hay cn gi l in thai th (Calling Card). Flash Operator Panel, Bng iu khin gim st tnh trng hot ng ca cc my in thoi trong h thng. Web MeetMe Control: Qun l trin khai h thng in thoi hi ngh. FreePBX: y l cng c vi giao din web dnh cho vic cu hnh h thng Asterisk.

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H thng Lu tr d phng v thng k: L thnh phn ca TRIXBOX, cung cp cc cng c cn thit cho vic bo tr bo dng h thng. H thng Apache-Php-Mysql dnh cho gii php Webserver ca h thng.2 DOWNLOAD V LP T TRIXBOX

a ch download http://sourceforge.net/projects/asteriskathome Khi download xong file Trixbox.iso. Hy dng file ny Burn vo CD (xin lu l dng Nero hoc chng trnh chp a a thch ri burn vo cd_rom ch khng phi chp file vo cd_rom.) Sau khi c CD, Hy boot t CD ny ci t trixbox. Ch : d liu trn a cng s b xa sch ci t trixbox. Nu trong a cng cn d liu hy backup tt c trc khi tin hnh lp t trixbox. Ti y ln lt cc mn hnh ch dn s hin ra v c theo hng dn m ci t. Sau khi ci t xong chng ta dng Username: root v password: password ng nhp h thng.3 Cu hnh a ch IP cho card mng:

Thit lp a ch IP bng cch g lnh:#netconfig

Chn OK thip lp Nu trong mng c h tr DHCP th hy chn mc ny cn nu khng hy nhp a ch IP tnh.

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IP: 192.168.0.1 Netmask: 255.255.255.0 Gateway: 192.168.93.254 //ng ra bn ngoi Primary nameserver: 192.168.93.200 // thit lp nu c Chn OK chp nhn cc thit lp trn. Sau khi hon tt hy lm cho thit lp c hiu lc bng cch reset li my tnh hoc dng lnh sau: #Service network stop #Service network start n y xem nh ci t hon tt by gi cu hnh c Asterisk chng ta vo mt my khc v m Internet Explorer hoc mt trnh duyt web bt k, nhp vo http://192.168.0.1 cu hnh trn, v tin hnh cu hnh h thng vi ti khong username: maint v password: password4 T Chc Th Mc ca Asterisk

Asterisk s dng nhiu th mc trn h thng linux qun l cc kha cnh khc nhau ca h thng, nh nghi nhn bn tin thoi, cc bn tin nhc thoi, hoc cc tp tin cu hnh. Phn ny s trnh by cc th mc chnh yu c to ra trong qu trnh lp t v c cu hnh trong tp tin Asterisk.conf.1 /etc/asterisk/

Th mc /etc/asterisk/ cha tt c cc tp tin cu hnh ca h thng Asterisk ngoi tr tp tin Zaptel.conf c t ti th mc /etc/. Phn cng Zaptel u tin c pht trin bi Jim Dixon thuc nhm Zapata TelephonyTc Gi L Quc Ton

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Group giao tip gia my tnh vi mng in thoi, m Asterisk li s dng phn cng ny, vi l do m file cu hnh zaptel.conf khng nm trong th mc /etc/asterisk/.2 /usr/lib/asterisk/modules/

Th mc /usr/lib/asterisk/modules/ cha tt c cc module cn thit asterisk hot ng. Bn trong th mc l cc ng dng khc nhau, cc codec, cc nh dng m thanh(format) v cc knh thng tin(channel). Theo mc nh Asterisk s np tt c cc module vo lc khi ng. Chng ta c th khng cho np mt module bt k bng cch khng khai bo s dng trong tp tin modules.conf. Lu khi khng cho np module th phi bit chc module khng lm nh hng hot ng ca asterisk nu khng li s xut hin.3 /var/lib/asterisk

Th mc /var/lib/asterisk/ cha tp tin astdb v mt s th mc con. Tp tin astdb nh v thng tin c s d liu ca Asterisk ging nh Microsoft Windows Registry. Cc th mc con ca th mc /var/lib/asterisk/ bao gm: agi-bin/ Th mc agi-bin/ cha cc script ca ngi dng m Asterisk c th nh v s dng qua cc ng dng AGI. AGI l phn giao tip vi ngn ng lp trnh script thc hin mt s cng vic ca Asterisk t bn ngoi.

firmware/

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Th mc firmware/ cha mt s phn do(firmware) cho cc thit b khc nhau tng thch vi Asterisk. Hin ti ch c th mc con /iax cha firmware cho thiy b IAXy ca Digium. IAXy l thit b ATA s dng giao thc IAX. images/ Cc ng dng thng tin vi cc knh h tr nh images th s dng th mc ny. Nhng hin ti cc knh thng tin hu nh khng h tr truyn nh images nn th mc ny cng him khi c s dng. Tuy nhin nu cc thit b c h tr th th mc ny tr nn hiu dng. keys/ Asterisk c th s dng h thng kho public/private xc minh cc kt ni gia cc server Asterisk thng qua ch k in t RSA. Nu t mt kho public vo th mc /keys th kt ni ca server u bn kia c th c xc minh bng knh thng tin c h tr, i vi Asterisk th knh giao thc IAX h tr loi xc minh ny. Mt kho private khng bao gi cng b, chng ta ch cng b kho public n vi server cn ni n, sau s c xc minh vi kho private ny. C hai kho public v private c lu vi ui .pub v .key t ti th mc keys/. mohmp3/ Khi cu hnh Asterisk s dng tnh nng Music on Hold, tnh nng hot ng s thc hin ly cc tp tin mp3 ti th mc mohmp3/. Tp tin nh dng theo chun ca Asterisk nn khi s dng cc file Mp3 thng thng cn c s chuyn i thch hp trc khi chp vo th mc trn s dng. sounds/

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Tt c cc tp tin m thanh lin quan n nhc thoi ca Asterisk c t ti th mc sounds/. Ni dung ca cc tp tin cha trong th mc c lit k qua tp tin sounds.txt t ti th mc m ngun ca Asterisk. Cn ni dung ca cc tp tin m thanh c m rng thm c lit k trong tp tin sounds-extra.txt t trong th mc c trch ra khi bung gi asterisk-sounds.4 /var/spool/asterisk/

Th mc /var/spool/asterisk/ Cha nhiu th mc con bao gm outgoing/, qcall, tmp/, voicemail/. Asterisk lun kim qua th mc outgoing v qcall v y l hai th mc cha cc tp tin dng text cha thng tin yu cu cuc gi. Cc tp tin cho php to ra cuc gi n gin bng cch chp tp tin ng cu trc quy nh vo th mc outgoing/. Sau y l cu trc cy th mc: 1 Hnh Cy th mc /var/spool/asterisk/

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Th mc tmp/ s dng lu tr nhng thng tin tm, lun bo m khng xy ra tnh trng c v vit tp tin cng mt lc. Khi yu cu x l tp tin chng ta thao tc trn th mc tmp/ trc khi lu vo tp tin ch. Tt c cc li nhc thoi t pha ngi s dng v cc li nhc thoi s dng cho thao tc hp voicemail u c cha trong th mc voicemail/. Mt hp th thoi c to ra ng vi mt my ni b trong tp tin voicemail.conf, s c to ra mt th mc con tng ng cho my ni b ti th mc voicemail/.

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5

/var/run/

Th mc /var/run/ cha thng tin process ID(pid) cho tt c cc tin trnh ang hot ng trong h thng, bao gm c Asterisk. Lu l ng vi mi h iu hnh th mc /var/run/ c th khc.6 /var/log/asterisk/

Th mc /var/log/asterisk/ l ni Asterisk cha tt c cc tp tin nht k hay cn gi l tp tin log. Chng ta c th tu bin cc loi thng tin c lu trong cc tp tin log khc nhau qua tp tin cu hnh logger.conf t ti th mc /etc/asterisk.7 /var/log/asterisk/cdr-csv

Th mc /var/log/asterisk/cdr-csv c s dng lu chi tit cuc gi CDR, Thng tin mc nh v chi tit thng tin cuc gi lu tr trong tp tin Master.CVS, nhng thng th ng vi mi m accountcode s to mt th mc ring lu chi tit cuc gi cho my .5 Mt s lnh thao tc trn h thng asterisk

Asterisk c hai thnh phn c xy dng tch hp vi nhau v chy song song nhau: Asterisk Server bnh thng chy ch nn(background) ging cc sevices trong window. Asterisk Client ch dng lnh CLI giao tip vi Asterisk Server, thc thi cc lnh kim tra, hay xem cc thng tin ca server. Chy v dng Asterisk ch nn chng ta thc hin lnh sau: #/etc/init.d/asterisk (start|stop)

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Mt khi Asterisk chy chng ta c th chuyn qua ch CLI t du nhc lnh ca linux nh sau: #asterisk r Khi vo ch lnh nu mun thot v li du nhc linux chng ta dng lnh: CLI>exit Cc lnh c bn thc hin ti CLI> Bt c khi no chnh sa cc tp tin cu hnh chng ta u cn phi np li cc thay i c hiu lc, iu thc hin bng lnh: #CLI>reload Bc ch debug cho knh thng tin SIP hoc IAX2 #CLI> IAX2 debug #CLI> SIP debug Tt ch debug cho knh thng tin SIP hoc IAX2 #CLI> IAX2 no debug #CLI> SIP no debug Hin th cc trng thi thng tin ca users, peers v

channels ca SIP hoc IAX2 #CLI> sip show users #CLI> sip show peers

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#CLI> sip show channels #CLI> iax2 show peers #CLI> iax2 show users #CLI> iax2 show channels n thi im ny c th ni chng ta hon thnh ci t h thng Asterisk, ci t xong mi l bc m u, cho h thng Asterisk hot ng vi tng ng dng c th chng s tip tc thc hin cc giai on c xem l quan trng nht trong vic trin khai h thng Asterisk, l giai on cu hnh h thng, ln k hoch Diaplan. chng cn li u nhm n mc tiu ny.

4

CU HNH H THNG ASTERISK

1

GII THIU

Sau khi hon tt phn ci t h thng asterisk, mt bc quan trng tip theo l cu hnh h thng, c th ni y l bc quan trng nht ca vic khin khai h thng n vi tng ng dng c th. Trong chng ny xin gii thiu ci nhn u tin v vic cu hnh trc khi i su hn nhng chng sau, nhng g gii thiu

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trong chng ny l nn mng c bn nhng hiu lm th no h thng c th hot ng c, ni dung chnh bao gm: + Thao tc cu hnh trn h thng tp tin ca asterisk. + Cch ci t phn mm softphone trn cng ngh sip. + Cu hnh cho hai my softphone lin lc vi nhau. + Cu hnh pht thng ip. + Quay s qua Sip v mng PSTN.2 Tp Tin cu hnh

Tt c cc file cu hnh cho h thng asterisk u nm ti th mc /etc/asterisk ngoi tr file zaptel.conf cu hnh cho phn cng TDM nm ti th mc /etc, cch thc cu hnh ging nh tp tin .ini ca window vy. Cc ni dung sau du chm phy ; l ni dung ch thch trong file cu hnh ging nh ch thch trong ngn ng lp trnh C l du //. Tt c cc khong trng trong tp tin u c b qua khng c ngha trong file cu hnh. Trong file cu hnh cn c hai php gn rt thng xuyn c s dng, php gn = l dng cho vic gn cc bin, cn php gn => dng cho vic gn cc i tng sau y l mt v d cho file cu hnh: Extention.conf

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; ;y l cc dng ch thch ; [section] Key=value [section2] Key=>object ; Gn gi tr cho i tng ; gn gi tr cho bin

C php thc hin ging nhau cho tt c cc file cu hnh nhng c vi kiu khc nhau cho mi file cu hnh da vo thc cch hot ng ca chng.3 Cc kiu nh hng trong tp cu hnh

C ba kiu cch thc hot ng ca tp tin cu hnh nh sau: Kiu Cch hot ng File cu hnh Extension.con 0) Zapata..conf [channels] Context=From_PSTN Signalling=fxs_ks Group=1 Channel=>1 C o m p l e x Mi entity nhn Entity mt ng cnh sip.conf iax.conf [cisco] Type=friend Secret=12345 V d Exten=>400,1,dial(sip/40

S i m p l e C hiu lc trn Group tng dng trong f file O p t i o n Dng khai bo inheritance sau tha k nhng thng s khai bo trc

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Host=192.168.16.5 Context=NoiBo [xten] Type=friend Secret=6789 Host=dynamic Context=NoiBo1 Simple Group

y l kiu cu hnh n gin nht thng s dng trong cc file extention.conf, meetme.conf, voicemail.conf tng ng vi mi dng khai bo l mt i tng c ngha trn dng . V d : Extention.conf[section] object1=> op1,op2,op3

object2=> op1b,op2b,op3b Trong v d trn mi dng tng ng vi cc ton t khc nhau object1 c cc ton t op1, op2, op3 trong khi object2 li c cc ton t op1b, op2b, op3b.2 Option inheritance

y l cu hnh kiu tha k thng c cu hnh trong cc file zapata.conf, agent.conf. vi kiu cu hnh ny th cc dng pha di c th tha k cc thng s dng pha trn, tng ng vi mi section cc dng pha di c th thay i cc thng s cho tng ng.Tc Gi L Quc Ton

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V d: Extention.conf [section] Op1=bas Op2=adv Object1=>1 Op1=int Object1=>2

Vi cu hnh trn c th gii thch nh sau object1=>1 tha hng hai thng s pha trn l op1=bas v op2=adv trong khi i vi object1=>2 vi thng s op1=int c khai bo li nn object1=>2 c tha k t hai thng s op1=int v op2=adv.3 Complex Entity

Vi cu kiu ny c t chc thnh nhiu entity, ng vi mi entity c nhiu thng s c khai bo, mi entity y chnh l cc section khai bo cc knh thng tin. Cu hnh thng c s dng trong cc file iax.conf, sip.conf. V d: Extention.conf

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[entity1] Op1=value1 Op2=value2 [entity2] Op1=value3 Op2=value4 Entity1 c cc gi tr value1 v value2 cho thng s op1 v op2, trong khi cng l thng s op1 v op 2 nhng c cc gi tr khc l value3 v value4 cho entity2.4 1 Cu hnh giao tip vi mng PSTN Ng cnh kt ni

kt ni vi mng PSTN chng ta cn phi c mt card TDM vi Cng FXO v mt ng dy in thoi hoc c th l mt tng i ni b PBX. C nhiu nh sn xut phn cng khc nhau nhng trong phn cu hnh di dy l cu hnh cho card zapata TDM01B ca digium (card ny hin nay gi bn khong 175$).

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Hnh Giao tip vi FXO v FXS

hnh trn chng ta ang tin hnh cu hnh cho port FXO.2 Lp t card TDM01B v cu hnh.

Trc khi lp t card TDM01B hy tt ngun my tnh v kim tra cng PCI c tng thch gn vo hay khng. Sau khi hon tt hy bt my tnh tr li v chun b cu hnh cho card hot ng. Cu hnh cho card hot ng thng qua hai file cu hnh l file zaptel.conf nm trong th mc /etc v file zapata.conf ti th mc /etc/asterisk, cu hnh trong file zapata.conf cho knh FXO hot ng. Ti thi im ny ch mc c bn nn khng gii thch k cc thng s cu hnh mt cch chi tit, nu mun tham kho thm k hn xin mi xem chng Cu Hnh Kt Ni Vi Mng PSTN

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gi li cc cu hnh c nn lu li phng bt trc cn khi phc li v sau bng lnh:#cp /etc/zaptel.conf /etc/zaptel.conf.old /etc/asterisk/zapata.conf.old

#cp /etc/asterisk/zapata.conf

/etc/zaptel.conffxsks=1 loadzone=us defaultzone=us

channels=1

/etc/asterisk/zapata.conf[channels] Group=1 context=default ;cuc gi vo s n [default] qua file extensions.conf signalling=fxs_ks channel => 1 ;S dng tn hiu FXS cho knh FXO

;ng dy in thoi c gn vi port 1

Sau khi cu hnh xong tin hnh np driver v np li file cu hnh cho card hot ng nh sau.Modprode zaptel Modprode wcfxo Ztcfg vvvvv Asterisk -vvvvvgc

5

Cu hnh in thoi IP SIP phone.

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Trong phn ny cng s gii thiu cu hnh khai bo n gin in thoi IP SIP phone, c thng tin chi tit hn xin mi tham kho chng Cu Hnh Giao Thc SIP v IAX Thc hin cu hnh trong file /etc/asterisk/sip.conf. Cc my in thoi s cu hnh trong file ny trc khi quay s hay nhn cuc gi.1 Phn khai bo Chung

Trong file sip.conf c section [general] dng khai bo cc thng s chung cho tt c cc knh sip trong ton b tp tin ny, nhng cc thng s c th mang gi tr khc trong phn khai bo trn cc knh ring ph hp vi knh . Sau y l cc thng s chnh: Allow/disallow: nh ngha s dng cc codec. Bindaddr: a ch IP m client kt ni n knh ny, nu thng s ny c khai bo l 0.0.0.0 cho php tt c cc a ch IP c th kt ni n knh ny. Context : Tt c cc cuc gi mc nh s c chuyn n ng cnh ny ngoi tr phn di file cu hnh c khai bo ng cnh khc. Bindport: Cng SIP UDP m client cn kt ni n. Maxexpirey: Thi gian ti a ng k, n v tnh bng giy. Defaultexpirey: Thi gian mc nh ng k, n v tnh bng giy. Register: kt ni giao tip vi server khc. V d:

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/etc/asterisk/sip.conf[general] Bindport=5060 Bindaddr=0.0.0.0 Context=default Disallow=all Allow=ulaw Maxexpirey=120 Defaultexpirey=80

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Khai bo knh SIP

Trong phn ny s khai bo cc knh sip ring cho tng in thoi ip sip phone, tt nhin cc thng s trong phn [general] s c hiu lc trn cc knh ny ngoi tr ti phn khai bo cc knh ny khai bo li thng s phn trn. Sau y l cc thng s dnh khai bo ring cho tng knh SIP: [name]: y l phn khai bo my in thoi extention ip sip, c th l k t nhng thng l cc con s quay v trn cc phm in thoi thng l cc con s m thi. Type: Kiu kt ni thng tin user, peer hay friend Host : a ch IP hay tn min m client kt ni vi knh ny thng dng gi tr l dynamic cho tt c client kt ni n.

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Secret : mt khu s dng knh ny. My in thoi pha client phi khai bo trng vi thng s ny th mi s dng c. V d: /etc/asterisk/sip.conf[8000] Type=friend Secret=123456 Context=NoiBo Host=dynamic

[8001] Type=friend Secret=2222 Context=NoiBo Host=192.168.5.16

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Gii Thiu DialPlan

Dialplan l tri tim ca h thng asterisk. Dialplan cho bit cc cuc gi s c x l nh th no qua h thng asterisk. Dialplan bao gm tp hp cc dng lnh hay cc ng dng theo mt trnh t no m h thng phi thc hin p ng nhu cu chuyn mch cuc gi. hiu r v cu hnh thnh cng h thng asterisk th iu kin tin quyt l phi bit nh th no dialplan hot ng. Dialplan l cng vic thit lp cho hot ng ca h thng nh nh hng cc cuc gi vo v ra h thng, l mt danh sch cc bc hay cc lnh lin tc nhau thc hin mt tc v no m h thng phi thc hin theo. Khc bitTc Gi L Quc Ton

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vi cc h thng in thoi truyn thng tt c cc cng vic cu hnh h thng u l t pha ngi s dng. H thng chng ta c hon chnh tt hay khng ph thuc rt nhiu vo vic chng ta hiu r vo dialplan hay khng?. Trong phn ny s tp trung i vo thc hin diaplan mc nn tng thc hin cuc gi trc khi i su tm hiu k nhng chng sau. Dialplan c cu hnh qua tp tin extension.conf, lin quan n vic cu hnh dialplan c nhng khi nim cn nm l: Extentions: in thoi ni b Priorities: Th t thc hin Applications: Cc ng dng Contexts: Cc ng cnh y ch cp n nhng khi nim c bn, hiu su hn v dialplan xin mi tham kho hai chng Dialplan. Trc khi cu hnh hy lu li tp tin extention.conf gc v thc hin trn file extention.conf rng.1 Extentions

Dialplan l mt tp gm nhiu extention, khi mt cuc gi tng ng vi extention no th ng dng cho cuc gi s c thc hin. extention c th n gin vi mt ch danh c th nh 8051, letoan hay l mt chui so mu c thc hin nh _9xxx.

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Cc dng ca extention.

V d : /etc/asterisk/extention.confexten=>8051,1,dial(sip/8051,20)

exten=>8051,2,hangup() exten=> ging nhau cho mi dng thc hin trong dialplan, 8051 l s in thoi m thu bao quay hay l extention, cn cc con s 1 v 2 l cc priorites tc l th t thc hin cc lnh. Khi thu bao quay s 8051 th chung my ip sip 8051 nu trong vng 20 giy m thu bao khng nhc my th kt thc cuc gi. Extension l thnh phn m asterisk thc hin theo, c kch hot khi c cuc gi vo extension chnh l con s m thu bao cn gi. Trong mi ng cnh

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s c th c nhiu extension. Extenstion chnh l ht nhn h thng xc nh cuc gi cn thc hin. Extenstion hon chnh gm c cc phn : exten => Name,priority,application( ) Name (Tn k t hoc con s) ca extension Priority (Mi extension c th bao gm nhiu bc mi bc c gi l priority) Application (or command) Thc hin mt ng dng c th no cho cuc gi Mt v d c th nh sau: /etc/asterisk/extention.confexten => 7325010,1,Dial(Zap/1,20) exten => 7325010,2,Voicemail(u7325010)

exten => Tng ng vi mi ng dng thc hin 7325010 Con s nhn c khi thu bao ch gi quay s. 1, 2 l cc priority th t c thc hin 1 ri ti 2 Trong v d ca chng ta con s 7325010 s c gi n knh zap/1 rung chung ti a 20 giy. Nu sau 20 giy khng tr li th cuc gi s c nh hng n hp th thoi u7325010 message. ch u y c ngha l 'u'navailable

2

Priorities Th t thc hin

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Priorities l th t thc hin cc ng dng trong dialplan, khi th t 1 c thc hin th k tip l ng dng ti th t s 2 c thc hin, k t vertion 1.2 ca Asterisk thay v s dng gn mt con s c th cho th t thc hin nh trn th y c th gn k t n cho mi dng exten=> iu ny s ni vi asterisk l ng dng vi th t tip theo s thc hin. V d: /etc/asterisk/extention.confexten=>8051,2,hangup() exten=>8051,1,dial(sip/8051,20)

v d trn dng c th t 2 ng trc dng c th t 1, nhng khi thc hin diaplan th dng c th t Priorities 1 u tin thc hin trc bt k th t sp xp nh th no. V d :

/etc/asterisk/extention.confexten=>8051,n,dial(sip/8051,20) exten=>8051,n,hangup()

Th t thc hin tng dng 1 t trn xung di.3 Aplications Cc hm ng dng

y l phn quan trng trong diaplan tc l ng dng no s c thc hin trn mi dng, cc ng dng nh thc hin quay s,tr li cuc gi hay n gin l nhc gc my bit thm thng tin v cc ng dng cng nh cc thng s km theo th hy dng lnh show Aplications trn giao tip dng lnh ca asterisk:

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CLI> show Aplications4 Contexts - Ng cnh

u tin hy hnh dung nh th ny, khi C Gio v Sinh Vin

trao i v

mn c s tin hc vin thng c ngha l ng cnh(context) lc ny ch tp trung vo lnh vc vin thng m thi. Nh vy ng cnh (context) c gii hn trong mt tnh hung c th, i vi Asterisk y cng th khi ni n ng cnh (context) th thng quan tm n trng hp c th no , iu ny r rng rng trong h thng s c rt nhiu ng cnh(context) khc nhau. V d khi gi n tng i Asterisk c mt thng ip thng bo nh sau Cho mng cc Bn gi n cng ty chng ti hy nhn phm 1 gp phng kinh doanh phm 2 gp phng k thut khi ngi gi chn phm 1 th h thng s chuyn n mt ng cnh (context) l [PhongKinhDoanh] khi ngi gi nhn phm 2 th h thng s nh hng cuc gi qua ng cnh (context) [PhongKyThuat] nh vy ng vi mi trng hp h thng s c ng cnh khc nhau, ng cnh c t trong du [] . /etc/asterisk/extention.conf[PhongKinhDoanh] exten => 7325010,1,Dial(SIP/${EXTEN}),20) exten => 7325010,2,Voicemail(u${EXTEN})

[PhongKyThuat] exten => _9.,1,Dial(SIP/${EXTEN})

Ngoi ta i vi vic cu hnh cho cc knh thoi th ng cnh y l vic x l cc cuc gi tng ng vi knh qua k hoch diaplan.Tc Gi L Quc Ton

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v d: /etc/asterisk/sip.conf[8051] Type=friend Context=Tu_SIP [8052] Type=friend Context=noibo

/etc/asterisk/extention.conf[noibo] exten=>8051,1,dial(sip/8051,20) exten=>8051,2,hangup() [Tu_SIP] exten=>8052,1,dial(sip/8052,20) exten=>8052,2,hangup()

Khi thu bao 8052 nhc my th Asterisk chuyn cuc gi ny n ng cnh [noibo] v ch nhn con s quay, nu thu bao 8052 quay s 8051 th s my 8051

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s rung chung trong vng 20 giy, nu qua 20 giy m thu bao 8051 khng nhc my th cuc gi s kt thc. Khi thu bao 8051 nhc my th Asterisk chuyn cuc gi ny n ng cnh [Tu_SIP] v ch nhn con s quay, nu thu bao 8051 quay s 8052 th s my 8052 s rung chung trong vng 20 giy, nu qua 20 giy m thu bao 8052 khng nhc my th cuc gi s kt thc.7 Ng cnh thc hnh ng dng

Hnh Ng cnh thc hnh ng dng Trong phn thc hnh ny chng ta cn trang b nhng thit b sau: + My tnh server asterisk.

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+ Hai my tnh client ci t hai softphone X-lite ni mng vi my tnh server asterisk. + giao tip vi PSTN cn trang b card FXO hoc nh cung cp dch v VoIP.1 Bc 1: Cu hnh cho hai sip phone X-lite 8051 v 8052 bng cch cu hnh trn file sip.conf nh sau:

/etc/asterisk/sip.conf

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[general] Bindport=5060 Bindaddr=0.0.0.0 Context=default Disallow=all Allow=ulaw Maxexpirey=120 Defaultexpirey=80

[8051] Type=friend Secret=123456 Context=NoiBo Host=dynamic Canreinvite=no

[8052] Type=friend Secret=2222 Context=NoiBo Host=dynamic Canreinvite=no

2

Bc 2: Cu hnh softphone x-lite pha client cho my 8051

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1. Chn settings trn menu

2. Thc hin khai bo cu hnh

nh sau:

3. Chn apply hoc ok xc nhn thng tin. 4. Ti y softphone c th kt ni vi server asterisk3 Bc 3 : Lp li bc hai khai bo my in thoi softphone 8052 8 To diaplan.

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By gi ti phn cho cc my in thoi khai bo trn c th thc hin cc cuc gi vi nhau th chng ta tin hnh thc hin dialplan, vic ny c cu hnh trong file extention.conf1 Thc hin mt v d c bn.

/etc/asterisk/extention.conf[incoming] Exten=>s,1,answer() Exten=>s,2,playback(hello_world) Exten=>s,3,hangup()

Th t Priority 1 thc hin ng dng tr li cuc gi cho tt c cc cuc gi n sau chuyn qua th t Priority k tip. Th t Priority 2 h thng s pht ra thng ip thoi t file m thanh helloworld.gsm. Cui cng Priority 3 kt thc cuc gi. Gii thch on lnh trn: Mt cuc gi nhn t cng giao tip FXO c gi n ng cnh [incoming], ng cnh ny c nh ngha trong file cu hnh zapata.conf, cc cuc gi vo c x l qua extention s, trong v d trn c 3 priorities, ng vi mi priorities l mt ng dng c gi thc hin. Extention s l mt extention c bit thc hin x l cc cuc gi vo khi con s c quay ca thu bao n h thng asterisk l khng bit trc. (v d cc cuc gi vo t giao tip FXO)

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Answer() Application thc hin tr li cuc gi trong trng thi cuc gi ang rung chung hoc mt s ng dng tr li cuc gi trc khi x l cuc gi. Playback() Application ng dng ny pht mt file m thanh c thu sn. Khi ng dng playback() thc thi th tt c cc con s c gi n t in thoi n phm u b loi b. c php playback(Tenfile). Tn file c th l dng .gsm hoc .wav, file m thanh c ly t th mc mc nh l (/var/lib/asterisk/sounds). Hangup() application ng dng kt thc cuc gi.2 Cc ng dng dial(), background() v goto().

thc hin dialplan thm phn uyn chuyn hn xin gii thiu thm 3 ng dng c bn na trong thc hin dialplan. Background() : ng dng ny thc hin pht mt file m thanh v ch nhn con s t phm nhn ca my in thoi, sau khi nhn con s t phm nhn my in thoi, asterisk s ngt pht thng ip v x l chuyn n s th t priority tng ng vi con s nhn c. c php ca ng dng:exten=>extention,priority,background(TnFile)

goto() : L ng dng thc hin nhy t context, extention, priority hin hnh n context, extention, priority c ch nh trong ng dng goto(). C php ca ng dng goto(): /etc/asterisk/extention.confexten=>extention,priority,goto(context,extention,priority) exten=>extention,priority,goto(extention,priority) exten=>extention,priority,goto(priority)

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Sau y l mt on lnh minh ha cho ng dng ca mt cng ty gm 3 phng ban l phng k thut, phng hnh chnh v phng tip th bn hng. Khi cuc gi n cng ty th h thng asterisk s pht thng ip mi nhn s chn phng ban cn lin lc. Thng ip Cho mng gi n cng ty ABC ca chng ti mi nhn phm 1 chuyn n phng K thut, phm 2 n phng hnh chnh v phm 3 n phng tip th bn hng sau khi ngi gi nhn phm tng ng vi 1,2,3 th s c thng bo v chuyn n phng ban tng ng. /etc/asterisk/extention.conf[incoming] Exten=>s,1,answer() Exten=>s,2,background(LoiChao) Exten=>s,3,hangup() Exten=>1,1,playback(KyThuat) Exten=>1,2,goto(kythuat,s,1) Exten=>2,1,playback(HanhChanh) Exten=>2,2,goto(HanhChanh,s,1) Exten=>3,1,playback(TiepThiBanHang) Exten=>3,2,goto(TiepThiBanHang,s,1)

Dial() : ng dng thc hin quay s in thoi, minh ha cho ng dng dial() chng ta ci thin on dialplan trn, thay v chuyn n ng cnh tng ng th thc hin quay trc tip n s in thoi ca phng ban . V d thc hin quay s SIP/8051 cho phng k thut, iax2/8000 cho phng Hnh Chnh v gi n zap/1 cho phng tip th bn hng.

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/etc/asterisk/extention.conf[incoming] Exten=>s,1,answer() Exten=>s,2,background(LoiChao) Exten=>s,3,hangup() Exten=>1,1,playback(KyThuat) Exten=>1,2,dial(sip/8051) Exten=>2,1,playback(HanhChanh) Exten=>2,2,dial(iax2/8000) Exten=>3,1,playback(TiepThiBanHang) Exten=>3,2,dial(zap/1)

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