Integrated Services Digital Network (ISDN) ndi teknoloji yamagetsi yomwe imathandizira kulumikiza kwa digito ya zamtundu umodzi komanso zamtundu wamtunduwu pamodzi ndi chithandizo cha kanema ndi fax. ISDN inayamba kutchuka padziko lonse lapansi muzaka za m'ma 1990 koma makamaka idakonzedwanso ndi matekinoloje apamtunda wamakono akutali.
Mbiri ya ISDN
Pamene makampani ojambulira mafoni anayamba kusintha mafoni awo kuchokera ku analog kupita ku digito, kugwirizana kwa malo ogona ndi mabungwe amalonda (omwe amatchedwa "makilomita otsiriza") ankakhalabe ndi miyezo yakale ya waya ndi waya. ISDN inapangidwa monga njira yosamukira teknolojia iyi kupita ku digito. Amalonda makamaka amapeza kufunika kwa ISDN chifukwa cha ma telefoni akuluakulu ndi mafakitale a mafakitale awo ma intaneti kuti athe kuthandizidwa mokhulupirika.
Kugwiritsa ntchito ISDN kwa Internet Access
Anthu ambiri adayamba kudziŵa za ISDN monga njira ina yowonjezera pa intaneti. Ngakhale mtengo wa utumiki wa intaneti wa ISDN unali wapamwamba kwambiri, ena ogula anali okonzeka kulipira zochuluka kwa ntchito yomwe inalengeza kufika 128 Kbps mofulumira kugwirizana ndi 56 Kbps (kapena pang'onopang'ono) mofulumira.
Kufikira ku intaneti ya ISDN kumafuna modem yadijito m'malo modemalo yokhala ndi miyambo, kuphatikizapo mgwirizano wautumiki ndi wopereka chithandizo cha ISDN. Potsirizira pake, maulendo apamwamba kwambiri omwe amagwiritsidwa ntchito pa intaneti amathandizidwa ndi matekinoloje atsopano a broadband Internet monga DSL inagula makasitomala ambiri kuchoka ku ISDN.
Ngakhale kuti anthu ochepa akupitiriza kuigwiritsa ntchito m'madera ochepa kumene kuli zosankha zabwino, ambiri opereka Intaneti athandizira thandizo lawo la ISDN.
The Technology Potsatira ISDN
ISDN imayenda pamtunda wamba kapena T1 mizere (E1 mizere m'mayiko ena); Sichimagwirizanitsa mauthenga opanda waya). Njira zozindikiritsira zomwe zimagwiritsidwa ntchito pa makanema a ISDN zimachokera kumalo olankhulirana, kuphatikizapo Q.931 pofuna kukhazikitsa mauthenga ndi Q.921 pofuna kulumikizana.
Kusiyana kwakukulu kwakukulu kwa ISDN kulipo:
- Chidule Chachidule (BRI-ISDN) : Maonekedwe a ISDN omwe ogula amazindikira ngati mwayi wa intaneti, BRI imagwira ntchito pazitsulo zamakono zamkuwa ndipo imathandizira ma 128 Kbps pazojambulidwa ndi kulandidwa. Njira ziwiri zogwiritsira ntchito deta (zotchedwanso DS-0 zogwirizanitsa mauthenga) zimanyamula detayi pomwe njira 16 Kbps imayendetsa mauthenga. Othandizira a Telecom nthawi zina amatchedwanso ISDN2 yokhudzana ndi makina awiriwa.
- Chidule cha PRI-ISDN : Njira iyi yapamwamba kwambiri ya ISDN imathandizira ma T1 onse a 1.544 Mbps (mpaka 2.048 Mbps pa E1). Pa T1, PRI imagwiritsa ntchito njira 23 zofanana zomwe zimanyamula katundu aliyense 64 Kbps, poyerekeza ndi 2 njira zoterezi za BRI. Ku Ulaya ndi Asia, operekera nthawi zambiri amatcha ISDN30 monga momwe mizere E1 yogwiritsidwira ntchito m'mayiko amenewo imathandizira njira 30 zonyamula katundu.
Njira yachitatu ya ISDN yotchedwa Broadband (B-ISDN) inafotokozedwanso. Fomu iyi yapamwamba kwambiri ya ISDN inapangidwa kuti izitha kufika mazana a Mbps, kuyendetsa zingwe za fiber optic ndi kugwiritsa ntchito ATM monga teknoloji yake yosintha. ISDN ya Broadband siinagwiritsidwe ntchito kwakukulu.