Inethiwekhi yocingo evamile iwukushintshana kwezwi ngesekhethi, i-broadband yokudlulisa edingekayo engu-64kbit/s.Okubizwa ngokuthi i-VoIP inethiwekhi yokushintshanisa iphakethe le-IP njengeplatifomu yokudlulisela, ukucindezelwa kwesignali yezwi okufanisiwe, ukupakishwa kanye nochungechunge lokucubungula okukhethekile, ukuze ikwazi ukusebenzisa i-protocol ye-UDP engaxhumekile yokudlulisa.
Kudingeka izici ezimbalwa nemisebenzi ukuze kudluliswe amasignali ezwi kunethiwekhi ye-IP.Indlela elula yenethiwekhi iqukethe amadivaysi amabili noma ngaphezulu anekhono le-VoIP axhunywe ngenethiwekhi ye-IP.
1.I-Voice-Data Transformation
Isignali yezwi iwuhlelo lwe-analog waveform, nge-IP ukudlulisa izwi, kungakhathaliseki ukuthi ibhizinisi lesicelo lesikhathi sangempela noma ibhizinisi lesicelo sesikhathi sangempela, okokuqala ukuya kukuguqulwa kwedatha ye-analog yezwi, okungukuthi isignali yezwi ye-analog engu-8 noma engu-6, bese ithunyelwa kusitoreji sebhafa. , usayizi webhafa ungakhethwa ngokuya ngezidingo zokulibaziseka nokubhala ikhodi.Izifaki khodi eziningi ze-bit rate eziphansi zifakwe ngekhodi kozimele.
Ubude obujwayelekile bozimele busuka ku-10 kuye ku-30 ms.Uma kucatshangelwa izindleko ngesikhathi sokudlulisa, amaphakethe ezilimi ezihlukene ngokuvamile aqukethe u-60, 120, noma 240ms wedatha yenkulumo.Ukufakwa kwedijithali kungenziwa kusetshenziswa izikimu ezihlukene zokubhala amakhodi ngezwi, futhi amazinga amanje okubhala ngekhodi yezwi ngokuyinhloko yi-ITU-T G.711.Isifaki khodi sezwi endaweni okuyiwa kuyo kufanele sisebenzise i-algorithm efanayo ukuze idivayisi yokukhuluma endaweni ikwazi ukubuyisela isignali yenkulumo ye-analog.
2.Original idatha-to-IP
Uma isignali yenkulumo isifakwe ikhodi yedijithali, isinyathelo esilandelayo ukucindezela iphakethe lenkulumo ngobude obuthile bohlaka.Iningi lamakhodi anobude obuthile bozimele.Uma isifaki khodi sisebenzisa ozimele abangu-15ms, iphakheji le-60ms elisuka endaweni yokuqala lihlukaniswa libe ozimele abane futhi lifakwe ikhodi ngokulandelana.Uhlaka ngalunye lunamasampula enkulumo angu-120 (isilinganiso sesampula esingu-8kHz).Ngemva kokufaka ikhodi, amafreyimu amane acindezelwe ahlanganiswa abe iphakheji yenkulumo ecindezelwe futhi athunyelwa kusicubunguli senethiwekhi.Iphrosesa yenethiwekhi yengeza i-Baotou, isikali sesikhathi, nolunye ulwazi ezwini futhi iludlulisele kwenye indawo yokugcina ngenethiwekhi.
Inethiwekhi yenkulumo ivele imise ukuxhumana ngokomzimba phakathi kwamaphoyinti okuxhumana (umugqa owodwa) futhi idlulise amasiginali afakwe ikhodi phakathi kwamaphoyinti.Ngokungafani namanethiwekhi okushintsha isifunda, amanethiwekhi e-IP awakhi uxhumo.Kudinga ukuthi idatha ifakwe emibikweni yedatha ende eguquguqukayo noma emaphaketheni, bese ikheli kanye nokulawula ulwazi kudathagram ngayinye futhi ithunyelwe ngenethiwekhi, idluliselwe endaweni okuyiwa kuyo.
3.Dlulisa
Kulesi siteshi, inethiwekhi yonke ibukwa njengephakethe lezwi elitholwe kokokufakayo bese lidluliselwa ekuphumeni kwenethiwekhi phakathi nesikhathi esithile (t).I-t ingahluka ebangeni eligcwele, ikhombisa i-jitter ekudluliselweni kwenethiwekhi.
Indawo efanayo kunethiwekhi ihlola ulwazi lwamakheli oluhlotshaniswa nedatha ye-IP ngayinye futhi isebenzisa lolu lwazi ukuze idlulisele leyo datagram esitobhini esilandelayo endleleni okuyiwa kuyo.Isixhumanisi senethiwekhi singaba yinoma iyiphi i-topology noma indlela yokufinyelela esekela ukusakazwa kwedatha ye-IP.
4.Iphakheji ye-IP- -ukuguqulwa kwedatha
Idivayisi ye-VoIP okuyiwa kuyo ithola le datha ye-IP bese iqala ukucutshungulwa.Izinga lenethiwekhi lihlinzeka ngebhafa yobude obuhlukile esetshenziselwa ukulawula i-jitter ekhiqizwa inethiwekhi.Isigcinalwazi singamumatha amaphakethe ezwi amaningi, futhi abasebenzisi bangakhetha usayizi webhafa.Amabhafa amancane akhiqiza ukubambezeleka okuncane, kodwa awalawuli ama-jitter amakhulu.Okwesibili, idikhoda ikhulula iphakethe lenkulumo elifakwe ikhodi ukuze kukhiqizwe iphakheji yenkulumo entsha, futhi le mojula ingasebenza futhi ngohlaka, ubude obufana ncamashi nobesikhikhoda.
Uma ubude bozimele bungu-15ms, amaphakethe ezwi angu-60ms ahlukaniswa abe ozimele abangu-4, abese ekhishwa ikhodi abuyele ekugelezeni kwedatha yezwi okungu-60ms futhi athunyelwe kubhafa yokukhipha amakhodi.Ngesikhathi sokucutshungulwa kombiko wedatha, ulwazi lwamakheli kanye nokulawula luyasuswa, idatha yoqobo iyagcinwa, bese le datha yoqobo ibe isinikezwa isikhiphi.
5.Inkulumo yedijithali iguqulelwe kunkulumo ye-analogi
Idrayivu yokudlala ikhipha amasampula ezwi (480) ku-buffer bese iwathumela ekhadini lomsindo ngesipika ngefrikhwensi enqunywe kusengaphambili (isb. 8kHz).Ngamafuphi, ukudluliswa kwezimpawu zezwi kunethiwekhi ye-IP kuhamba ngokuguqulwa kusuka kusignali ye-analog kuya kusignali yedijithali, ukupakishwa kwezwi ledijithali kuphakethe le-IP, ukuhanjiswa kwephakethe le-IP ngenethiwekhi, ukuqaqa iphakethe le-IP kanye nokubuyiselwa kwezwi ledijithali ku-analog. isignali.
Okwesibili, izindinganiso zobuchwepheshe ezihlobene ne-VoIP
Kuzinhlelo zokusebenza ze-multimedia kumanethiwekhi okuxhumana akhona, i-International Telecommunication Union (ITU-T) ithuthukise iphrothokholi yochungechunge lokuxhumana lwe-H.32x Multimedia, amazinga alandelayo amakhulu ukuze uthole incazelo elula:
H.320, Izinga lokuxhumana kwe-multimedia kusistimu yocingo yevidiyo ye-narrowband kanye netheminali (N-ISDN);
H.321, Izinga lokuxhumana kwe-multimedia ku-B-ISDN;
H.322.Izinga lokuxhumana kwe-multimedia ku-LAN okuqinisekiswe yi-QoS;
H.323.Izinga lokuxhumana kwe-multimedia kunethiwekhi yokushintsha iphakethe ngaphandle kwesiqinisekiso se-QoS;
H.324, indinganiso yokuxhumana kwemultimedia kumatheminali okuxhumana anesilinganiso esincane sebhithi (PSTN kanye nenethiwekhi engenantambo).
Phakathi kwamazinga angenhla, H. Amanethiwekhi e-323 Standard-defined iwona asetshenziswa kakhulu, njenge-Ethernet, Token Network, FDDI Network, njll.ngenxa ye-H. Ukusetshenziswa kwe-323 okujwayelekile sekuphenduke indawo eshisayo emakethe, ngakho-ke ngezansi sizogxila ku-H.323.H.323 Izingxenye ezine eziyinhloko zichazwe esiphakamisweni: itheminali, isango, isofthiwe yokuphatha isango (eyaziwa nangokuthi isango noma isango), kanye neyunithi yokulawula yamaphoyinti amaningi.
1.Itheminali (Itheminali)
Wonke amatheminali kufanele asekele ukuxhumana ngezwi, futhi amandla okuxhumana kwevidiyo nedatha angokuzithandela.yonke i-H.Itheminali engu-323 kufanele futhi isekele i-H.245 Standard, H.245 Izinga lisetshenziselwa ukulawula ukusetshenziswa kwesiteshi nokusebenza kwesiteshi.H .323 Amapharamitha ayinhloko ekhodekhi yenkulumo ekuxhumaneni kwezwi acaciswe kanje: Umkhawulokudonsa wezwi onconyiwe we-ITU / isilinganiso sebhithi sokudlulisa se-KHz / isichasiselo se-algorithm yokucindezela i-Kb/s G.711 3.4 56,64 PCM yokucindezelwa okulula, okusetshenziswe ku-PSTN ku-G .728 3.4 16 Ikhwalithi yezwi ye-LD-CELP njenge-G.711, njengoba isetshenziswa ekudluliselweni kwezinga eliphansi G.722 7 48,56,64 ADPCM ikhwalithi yezwi ingaphezu kwe-G.711, isetshenziswa ekudluliselweni kwesilinganiso sebhithi esiphezulu G. .723.1G.723.0 3.4 6.35.3 LP-MLQ Ikhwalithi yezwi iyamukeleka, G.723.1 Adopt a G wenkundla ye-VOIP.729G.729A 3.4 8 Ukubambezeleka kwe-CS-ACELP kungaphansi kune-G.723.1, Ikhwalithi yezwi ingaphezulu G.723.1.
2.Isango (Isango)
Lena inketho ye-H.An yesistimu engu-323. Isango lingaguqula izimiso, umsindo, ama-algorithms ekhodi yevidiyo kanye namasignali okulawula asetshenziswa amasistimu ahlukene ukuze afakele ukuxhumana kwesiphetho sesistimu.Njenge-PSTN-based of H.324 System kanye nebhande elincane I-ISDN-based H.The 320 System kanye ne-H.323 Ngokuxhumana kwesistimu, kuyadingeka ukulungisa isango;
3. Ukugcinwa kwamasiko (Umgcini-sango)
Lena H.Ingxenye yokuzikhethela yesistimu ye-323 isofthiwe yokuqedela umsebenzi wokuphatha.Inemisebenzi emibili eyinhloko: owokuqala ungowokuphatha Uhlelo lwe-H.323;okwesibili ukuphatha ukuxhumana kwetheminali ngesango (njengokusungulwa kwezingcingo, ukususwa, njll.).Abaphathi bangenza ukuguqulwa kwekheli, ukulawulwa komkhawulokudonsa, ukuqinisekiswa kwekholi, ukurekhoda ucingo, ukubhaliswa komsebenzisi, ukuphathwa kwesizinda sokuxhumana kanye neminye imisebenzi ngokusebenzisa amasiko. ukugcina.okukodwa H.323 Isizinda sokuxhumana singaba namasango amaningi, kodwa isango elilodwa kuphela elisebenzayo.
4.Iyunithi yokulawula yamaphoyinti amaningi (Iyunithi Yokulawula Amaphoyinti amaningi)
I-MCU inika amandla ukuxhumana kwamaphuzu amaningi kunethiwekhi ye-IP, futhi ukuxhumana kwephuzu nephuzu akudingeki.Lonke uhlelo lwakha i-topology yenkanyezi nge-MCU.I-MCU iqukethe izingxenye ezimbili eziyinhloko: isilawuli se-multipoint MC kanye ne-multipoint processor MP, noma ngaphandle kwe-M.H phakathi kwamatheminali okucubungula e-MC.245 Lawula ulwazi ukuze wakhe igama elincane lomphakathi ukuze kucutshungulwe umsindo nevidiyo.I-MC ayicubunguli ngokuqondile noma yikuphi ukusakazwa kolwazi lwemidiya, kodwa iyishiyela ku-MP.I-MP.I-MP ihlanganisa, ishintshe, futhi icubungule umsindo. , ividiyo, noma ulwazi lwedatha.
Embonini kunezakhiwo ezimbili ezifanayo, enye i-ITU-T H eyethulwe ngenhla.323 Protocol iphrothokholi ye-SIP (RFC2543) ehlongozwe yi-Internet Engineering Task Force (IETF), futhi iphrothokholi ye-SIP ifaneleka kakhulu kumatheminali ahlakaniphile.
Okwesithathu, Umfutho wokuthuthukiswa kwe-VoIP
Ukusetshenziswa okusabalele kwe-VoIP kuzofezeka ngokushesha ngenxa yezingxenyekazi zekhompuyutha eziningi, isofthiwe, intuthuko ehlobene kanye nempumelelo yezobuchwepheshe esivumelwaneni namazinga.Intuthuko nentuthuko yezobuchwepheshe kule mikhakha idlala indima eshayelayo ekudaleni inethiwekhi ye-VoIP esebenza kahle, esebenzayo futhi esebenzisanayo. Izici zobuchwepheshe ezikhuthaza ukuthuthuka okusheshayo kanye nokusetshenziswa okusabalele kwe-VoIP kungafingqwa ngezici ezilandelayo.
1.Digital Signal Processor
Amaphrosesa wesignali yedijithali athuthukile (I-Digital Signal Processor, i-DSP) enza izingxenye ezidinga kakhulu ukubala ezidingekayo ekuhlanganisweni kwezwi nedatha.I-DSP icubungula amasignali edijithali ikakhulukazi ukuze yenze izibalo eziyinkimbinkimbi okungenzeka uma kungenjalo zenziwe yi-CPU yendawo yonke.Inhlanganisela yezobuchwepheshe bazo obukhethekile. amandla okucubungula anezindleko eziphansi kwenza i-DSP ifaneleke kahle ukwenza imisebenzi yokucubungula isignali ohlelweni lwe-VoIP.
Ukusakaza kwezwi elilodwa ku-G.729 Izindleko zekhompuyutha zokuminyanisa izwi ngokuvamile zinkulu, ezidinga u-20MIPS.Uma i-CPU emaphakathi idingeka ukwenza imisebenzi yomzila kanye nokuphathwa kwesistimu ngenkathi icubungula ukusakaza kwezwi okuningi, lokhu akunangqondo.Ngakho-ke, ukusebenzisa i-DSP eyodwa noma ngaphezulu kungakhipha umsebenzi wekhompuyutha we-algorithm yokucindezela izwi eyinkimbinkimbi ku-CPU emaphakathi.Ngaphezu kwalokho, i-DSP ifanele ukutholwa komsebenzi wezwi nokukhanselwa kwe-echo, okubavumela ukuthi bacubungule ukusakazwa kwedatha yezwi ngesikhathi sangempela futhi bafinyelele ngokushesha. inkumbulo esebhodini, ngakho.Kulesi sigaba, sichaza kabanzi ukuthi ungayisebenzisa kanjani ukubhala ikhodi yezwi kanye nokukhanselwa kwe-echo kuplathifomu ye-TMS320C6201DSP.
Iphrothokholi nesofthiwe evamile nezingxenyekazi zekhompuyutha H.323 Indlela yokubeka umugqa enesisindo efanelekile ye-DSP MPLS ukushintshisana komaka kukalwe ukutholwa kwangaphambi kwesikhathi okungahleliwe okuthuthukisiwe kwe-ASIC RTP, i-RTCP embaxambili yefaneli evamile yesilinganiso se-algorithm ye-DWDM RSVP elinganiselwe ukufinyelela okusheshayo SONET Diffserv, CAR Cisco idlulisela ngokushesha i-CPU amandla okucubungula G. 729, G.729a: Ithebula Lokufinyelela Okunwetshiwe le-CS-ACELP ADSL, RADSL, SDSL FRF.11/FRF.12 I-algorithm yethokheni yomphongolo we-Multilink PPP Frame Relay Relay Data SIP esekelwe ekuhlanganisweni okubalulekile kwe-CoS Packet phezu kwe-SONET IP ne-ATM QoS / CoS
2.Amasekhethi ahlanganisiwe azinikele athuthukile
Ukuthuthukiswa kwe-Application-Specific Integrated Circait (ASIC) kukhiqize i-ASIC.ASIC esheshayo, eyinkimbinkimbi, futhi esebenza kakhudlwana i-chip eyisipesheli eyenza isicelo esisodwa noma isethi encane yemisebenzi.Ngenxa yokuthi igxile emigomweni yohlelo lokusebenza emincane kakhulu, zingalungiselelwa kakhulu imisebenzi ethile, ngokuvamile nge-CPU enezinjongo ezimbili eyodwa noma ama-oda amaningana obukhulu ngokushesha.
Njengoba nje i-chip ye-Thin Instruction set Computer (RSIC) igxile ekwenziweni ngokushesha kwezinombolo ezilinganiselwe, i-ASIC ihlelwe kusengaphambili ukuthi yenze inani elilinganiselwe lemisebenzi ngokushesha.Uma ukuthuthukiswa sekuqediwe, izindleko zokukhiqiza ngobuningi be-ASIC ziphansi, futhi iyasetshenziswa. kumadivayisi enethiwekhi okuhlanganisa amarutha namaswishi, ukwenza imisebenzi efana nokuhlola itafula lomzila, ukudlulisela phambili kweqembu, ukuhlela nokuhlola iqembu, kanye nokubeka umugqa.Ukusetshenziswa kwe-ASIC kunikeza idivayisi ukusebenza okuphezulu kanye nezindleko eziphansi.Banikeza i-broadband eyengeziwe kanye nokusekelwa okungcono kwe-QoS inethiwekhi, ngakho-ke badlala indima enkulu ekuthuthukiseni i-VoIP.
I-3.IP yokudlulisa ubuchwepheshe
Amanethiwekhi amaningi okuxhumana ezokuxhumana asebenzisa ukuphindaphinda kokuhlukaniswa kwesikhathi, kuyilapho i-inthanethi kufanele isebenzise ukusetshenziswa kabusha kwezibalo nokushintshisana kwephakethe elide.Uma kuqhathaniswa, lokhu kokugcina kunezinga eliphezulu lokusetshenziswa kwezinsiza zenethiwekhi, ukuxhumana okulula nokuphumelelayo, futhi kusebenza kakhulu kumasevisi wedatha, okungenye yezizathu ezibalulekile zokuthuthukiswa okusheshayo kwe-Inthanethi.Nokho, ukuxhumana kwenethiwekhi ye-broadband IP kudinga i-QoS nezici zokulibaziseka. , ngakho ukuthuthukiswa kokushintshisana kwephakethe lokuphindaphinda kwezibalo kuye kwakhanga ukukhathazeka.Okwamanje, ngaphezu kwesizukulwane esisha se-IP protocol-IPV6, i-world Internet engineering task group (IETF) ihlongoze ubuchwepheshe bokushintshanisa ithegi ye-multi-protocol (MPLS), lokhu iwuhlobo lokukhethwa kwesendlalelo senethiwekhi okusekelwe ukushintshaniswa kwethegi / ilebula ehlukahlukene, ingathuthukisa ukuguquguquka kokukhetha umgwaqo, yandise ikhono lokukhetha ungqimba lwenethiwekhi, yenza lula umzila nokuhlanganiswa kokushintshisana kwesiteshi, ithuthukise ukusebenza kwenethiwekhi.MPLS ingasebenza njengephrothokholi yomzila ezimele, futhi iyahambisana nephrothokholi yomzila wenethiwekhi ekhona, isekela ukusebenza okuhlukahlukene, ukuphatha kanye nokugcinwa kwemisebenzi ye-IP network, yenza i-QoS, umzila, ukusebenza kokubonisa kuthuthukiswe kakhulu, ukufinyelela noma eduze nezinga lokusebenzisa kabusha iphakethe lokushintshana kwepakethe yezibalo ezihleliwe (i-ATM), futhi elula, ephumelelayo, eshibhile futhi esebenzayo kune-ATM.
I-IETF futhi endaweni ibamba ubuchwepheshe obusha beqembu, ukuze kuzuzwe ukukhetha komgwaqo we-QoS. "Ubuchwepheshe bomhubhe" buyacwaningwa ukuze kuzuzwe ukudluliswa kwe-broadband yezixhumanisi zendlela eyodwa. Ngaphezu kwalokho, indlela yokukhetha iplatifomu yokudlulisa inethiwekhi ye-IP nayo iyinhlangano. umkhakha obalulekile wocwaningo eminyakeni yamuva nje, kanye ne-IP phezu kwe-ATM, i-IP phezu kwe-SDH, i-IP phezu kwe-DWDM nobunye ubuchwepheshe buvele ngokulandelana.
Isendlalelo se-IP sinikeza abasebenzisi be-IP izinsizakalo zokufinyelela ze-IP zekhwalithi ephezulu ngeziqinisekiso ezithile zesevisi.Isendlalelo somsebenzisi sinikeza ifomu lokufinyelela (ukufinyelela kwe-IP nokufinyelela kwe-broadband) kanye nefomu lokuqukethwe kwesevisi.Kusendlalelo esiyisisekelo, i-Ethernet, njengesendlalelo esibonakalayo inethiwekhi ye-IP, kuyindaba yeqiniso, kodwa i-IP overDWDM inobuchwepheshe bakamuva, futhi inamandla amakhulu okuthuthuka.
I-Dense Wave Division MultipLexing (DWDM) ijova impilo entsha kumanethiwekhi e-fiber futhi inikeza umkhawulokudonsa omangalisayo ezinkampanini zezingcingo ezibeka i-fiber backbone entsha.Ubuchwepheshe be-DWDM busebenzisa amandla ama-optical fibers kanye nemishini yokudlulisa amehlo ethuthukisiwe.Igama le-wave division multiplexing lisuselwa ekudluliseni okuningi. amaza okukhanya okukhanya (i-LASER) asuka emfudlaneni owodwa we-fiber optical.Amasistimu amanje angathumela futhi abone amaza angamaza angu-16, kuyilapho amasistimu esikhathi esizayo angakwazi ukusekela amaza angama-40 kuya kwangu-96 agcwele. ngakho-ke nwebisa inethiwekhi ye-2.6 Gbit/s (OC-48) izikhathi ezingu-16 ngaphandle kokubeka imicu emisha.
Amanethiwekhi amaningi e-fiber amasha asebenzisa i-OC-192 ku-(9.6 Gbit/s), akhiqiza amandla angaphezu kuka-150 Gbit/s kumafayibha amabili uma ehlanganiswa ne-DWDM.Ngaphezu kwalokho, i-DWDM inikeza iphrothokholi yesixhumi esibonakalayo nezici ezizimele ngesivinini, futhi isekela kokubili i-ATM. , i-SDH kanye ne-Gigabit Ethernet yokudlulisa isignali ku-fiber eyodwa, engahambisana namanethiwekhi akhona, ukuze i-DWDM ikwazi ukuvikela impahla ekhona, kodwa futhi inikeze izinkampani ze-ISP ne-telecom ngomgogodla oqinile, futhi zenze i-broadband ingabizi futhi ifinyeleleke kakhudlwana, ehlinzeka ukwesekwa okuqinile kwezidingo zomkhawulokudonsa wezixazululo ze-VoIP.
Izinga lokudlulisela elikhuphukile alikwazi nje ukunikeza ipayipi eliqinile elinethuba elincane lokuvinjwa, kodwa futhi linciphise ukubambezeleka kakhulu, futhi ngaleyo ndlela linganciphisa kakhulu izidingo ze-QoS kumanethiwekhi e-IP.
4.Ubuchwepheshe bokufinyelela ku-Broadband
Ukufinyelela komsebenzisi kwenethiwekhi ye-IP sekuphenduke ibhodlela elikhawulela ukuthuthukiswa kwayo yonke inethiwekhi.Esikhathini eside, umgomo wokugcina wokufinyelela komsebenzisi i-fiber-to-home (FTTH).Ngokolimi olubanzi, inethiwekhi yokufinyelela optical ihlanganisa i-optical digital loop carrier system. kanye nenethiwekhi ye-passive optical.Eyokuqala ise-United States, ehlanganiswe nomlomo ovulekile i-V5.1/V5.2, idlulisela uhlelo lwayo oludidiyelwe ku-fiber optical, okubonisa amandla amakhulu.
Lesi sakamuva sise-oda futhi siseJalimane.Isikhathi esingaphezu kweminyaka eyishumi, iJapane ithathe uchungechunge lwezinyathelo zokunciphisa izindleko zenethiwekhi ye-passive optical ibe sezingeni elifana nezintambo zethusi kanye ne-metal twisted pair, futhi yayisebenzisa ukuyisebenzisa.Ikakhulukazi eminyakeni yamuva nje, i-ITU ihlongoze inethiwekhi ye-ATM-based passive Optical network (APON), ehambisana nezinzuzo ze-ATM kanye nenethiwekhi ye-passive optical network.Izinga lokufinyelela lingafinyelela ku-622 M bit/s, okuzuzisa kakhulu ekuthuthukisweni kwesevisi ye-multimedia ye-Broadband IP, futhi linganciphisa izinga lokuhluleka kanye nenani lama-node, futhi landise ukumbozwa.Okwamanje, i-ITU isiwuqedile umsebenzi wokulinganisa. , abakhiqizi bathuthukisa ngenkuthalo, kuzoba nezimpahla emakethe, kuzoba isiqondiso esiyinhloko sokuthuthukiswa kobuchwepheshe bokufinyelela kwe-broadband ekhulwini lama-21.
Njengamanje, ubuchwepheshe obuyinhloko bokufinyelela yilezi: PSTN, IADN, ADSL, CM, DDN, X.25 kanye ne-Ethernet kanye nekholomu yesistimu yokufinyelela okungenantambo ye-broadband, njll.Lobu buchwepheshe bokufinyelela bunezici zabo siqu, kufaka phakathi i-ADSL ne-CM ekhula ngokushesha kakhulu;I-CM (I-Cable Modem) isebenzisa intambo ye-coaxial, izinga eliphezulu lokudlulisela, ikhono eliqinile lokulwa nokuphazamiseka;kodwa hhayi ukudluliswa kwezindlela ezimbili, alikho izinga elifanayo.I-ADSL (I-Asymmetrical Digital Loop) inokufinyelela okukhethekile ku-broadband, isebenzisa ngokugcwele inethiwekhi yocingo ekhona futhi ihlinzeka ngezinga lokudluliswa kwe-asymmetric.Izinga lokulanda ohlangothini lwabasebenzisi lingafinyelela ku-8 Mbit/s, futhi izinga lokulayisha ohlangothini lomsebenzisi lingafinyelela ku-1M bit / s.ADSL inikeza i-broadband edingekayo yamabhizinisi nabo bonke abasebenzisi, futhi kunciphisa kakhulu izindleko.Ukusebenzisa i-ADSL ebiza kancane izifunda, izinkampani manje zifinyelela ku-inthanethi kanye ne-VPN esekelwe ku-inthanethi ngesivinini esiphezulu, okuvumela umthamo wekholi we-VoIP ophezulu.
5.Central processing unit technology
I-Central processing units (CPU) iyaqhubeka nokuvela ekusebenzeni, emandleni, kanye nasesivinini.Lokhu kuvumela ukusetshenziswa kabanzi kwe-PC ye-multimedia futhi kuthuthukisa ukusebenza kwemisebenzi yesistimu elinganiselwe amandla e-CPU.Ikhono le-PC lokucubungula idatha yomsindo nevidiyo esakazwayo kade ilindelwe. ngabasebenzisi, ngakho-ke ukuletha izingcingo zezwi kumanethiwekhi edatha ngokwemvelo kungumgomo olandelayo.Lesi sici sekhompuyutha sivumela kokubili izinhlelo zokusebenza ezithuthukisiwe zedeskithophu ye-multimedia nezici ezithuthukisiwe ezingxenyeni zenethiwekhi ukusekela izinhlelo zokusebenza zezwi.