Inethiwekhi yedijithali yeNkonzo (Integrated Network Network Network) (ISDN) iteknoloji yechungechunge exhasa ukutshintshwa kwedatha yezwi kunye nedatha yexeshanye ngexesha kunye nenkxaso yevidiyo kunye nefeksi. I-ISDN yafumana ukuthandwa emhlabeni jikelele ngee-1990 kodwa ikhululeke kakhulu kwiinkqubo zamanethiwekhi ezinxibelelwano ezide.
Imbali ye-ISDN
Njengoko iinkampani zethungelwano zeteknoloji zatshintshisa iinkcukacha zabo zefowuni ukusuka kwi-analog ukuya kwidijithali, ukudibanisa kunye neendawo zokuhlala kunye namashishini (okubizwa ngokuba yi-"mile yokugqibela" inethiwekhi) yahlala kwimigangatho yokudala yokubonisa kunye nentambo yobhedu. I-ISDN yenzelwe njengendlela yokufudukela kule teknoloji kwidijithali. Amashishini afumaneke ngakumbi kwixabiso le-ISDN ngenxa yeenombolo ezinkulu zeefowuni kunye neefowuni zeefeksi zabo zokunxibelelana ezifunekayo ukuze zixhaswe ngokuthembeka.
Ukusebenzisa i-ISDN kwi-Internet Access
Abantu abaninzi baqala ukumazi nge-ISDN njengenye indlela yokufikelela kwi-intanethi ye-intanethi. Nangona iindleko ze-Intanethi ye-Intanethi yeenkonzo zokuhlala ziphezulu, abanye abathengi babekulungele ukuhlawula ngaphezulu inkonzo epapashwa ukuya kwi-128 Kbps ngesixinano sokuxhamla ngokumalunga no-56 Kbps (okanye ihamba ngokukhawuleza) ngokukhawuleza.
Ukukhangela kwi-intanethi ye-ISDN kwakudinga imodem yedijithali endaweni ye- modem yokudityaniswa kwemveli, kunye nekhontrakthi yenkonzo kunye nomnikezeli wesevisi ye-ISDN. Ekugqibeleni, isantya esiphezulu somnxeba esekelwe ngeteknoloji ye-intanethi entsha ye-intanethi njengeDSL yabangela ukuba abathengi abaninzi bangabikho kwi-ISDN.
Nangona abantu abambalwa baqhubeka beyisebenzisa kwiindawo ezincinci apho abantu abanakho ukhetho olungcono, abaninzi ababoneleli nge-intanethi baye baphumelela ngenkxaso yabo kwi-ISDN.
IThekhnoloji ye-ISDN
I-ISDN isebenza ngaphaya kwemizila yefoni okanye imizila ye-T1 (imizila ye-E1 kwamanye amazwe); ayixhasi uxhumano lwe-wireless). Izindlela zokubonisa iindlela ezisetyenziselwa kumanethiwekhi e-ISDN zivela kwintsimi yee-telecommunications, kuquka ne-Q.931 yokumisela uxhumano kunye ne-Q.921 malunga nokufikelela kwekhonkco.
Iintlobo ezimbini ezibalulekileyo ze-ISDN zikhona:
- IsiQinisekiso seMali esiSiseko (I-BRI-ISDN) : Ifom ye-ISDN yokuba abathengi bayakubona njengendlela yokufikelela kwi-Intanethi, i-BRI isebenza ngokubhekiselele kumgca wocingo wobhedu obuqhelekileyo kwaye ixhasa amaxabiso e-128 Kbps kokulayishwa kunye nokulandwa. Iziganeko ezibini zee-64 Kbps ezibizwa ngokuba ngamashishini anezixhobo (ezibizwa ngokuba yi-DS-0 izixhumanisi kwi-telecommunications) zithatha idatha ngelixa umzila we-16 Kbps ulawula ulwazi lolawulo. Ababoneleli ngeeTelkom ngamanye amaxesha bayabiza le nkonzo ye- ISDN2 ebhekiselele kwi- setha yedatha yokusetha idatha.
- I-Interface-rate ye-Primary (I-PRI-ISDN) : Le fom ye-ISDN iphakamileyo ixhasa i-T1 ngesivinini se-1.544 Mbps (kwaye ifike kwi-2.048 Mbps kwi-E1). Kwi-T1, i-PRI isebenzisa izithuthi ezingama-23 ezifanayo eziphethe i-64 Kbps zendlela, xa kuthelekiswa neendlela ezi-2 ze-BRI. EYurophu nakwi-Asiya, ababoneleli bavame ukubiza le nkonzo ye- ISDN30 njengemigca ye-E1 esebenzayo kulawo mazwe axhaswa ngamashishini angama-30.
Ifom yesithathu ye-ISDN ebizwa ngokuba yi- Broadband (B-ISDN) ichazwe kwakhona. Ifom yeyona ndlela ephakamileyo kakhulu ye-ISDN yenzelwe ukufikelela kwii-Mbps zamakhulu, ukugijima kwii- fiber optic kunye nokusebenzisa i- ATM njengeteknoloji yokuguqula. I-ISDN ye-Broadband ayizange ifumaneke ukusetyenziswa okuqhelekileyo.