I-X.25 yayiyi-suite yenethiwekhi ye-protocol yokukhetha eminyakeni yama-1980
I-X.25 yayiyi-suite ejwayelekile yama-protocol asetshenziselwa ukuxhumana kwepakethe-switched phezu kwenethiwekhi yendawo enkulu-i- WAN . Iprotocol isethi yokuvunyelwana kwezinqubo nemithetho. Amadivaysi amabili alandela ama- protocols afanayo angaqonda futhi adlulise idatha.
Umlando we-X.25
I-X.25 yasungulwa ngonyaka wama-1970 ukuphatha izwi phezu kwemizila yocingo ye-analog- amanethiwekhi okudayela-up -futhi enye yezinsizakalo ezindala kakhulu zokushintshwa kwepakethe. Izicelo ezijwayelekile ze-X.25 zazihlanganisa amanethiwekhi omshini wokuzwakalisa othomathikhi kanye namanethiwekhi wokuqinisekiswa kwekhadi lesikweletu. I-X.25 nayo isekela izinhlobo ezihlukahlukene ze-mainframe ukugcina nezicelo zeseva. Ngama-1980 kwakuyizinsuku zobuchwepheshe be-X-25 lapho zisetshenziselwa amanethiwekhi omphakathi wedatha Compuserve , Tymnet, Telenet, nabanye. Ekuqaleni kuka-90s, amanethiwekhi amaningi angu-X.25 ashintshwa ngu- Frame Relay e-US Amanye amanethiwekhi omphakathi asekudala ngaphandle kwe-US aqhubeka nokusebenzisa i-X.25 kuze kube yamuva. Amanethiwekhi amaningi adingekayo i-X.25 manje asebenzisa i-Intanethi ye-intanethi encane kakhulu. I-X-25 isasetshenziselwa kwamanye ama-ATM kanye namanethiwekhi wokuqinisekiswa kwekhadi lesikweletu.
Isakhiwo se-X-25
Iphakeji ngalinye le-X.25 liqukethe kuze kube ngu-128 byte yedatha. Inethiwekhi ye-X.25 isebenze umhlangano wepakethe kudivayisi yomthombo, ukulethwa, nokubuyisela endaweni lapho uya khona. I-X.25 itheknoloji yokulethwa kwepakethe ayihlanganisi nje ukushintshwa nokuhlelwa kwezintambo zenethiwekhi kodwa futhi ukuhlola iphutha nokubhala kabusha kwelogi kufanele kube khona ukwehluleka kwezidingo. I-X.25 isekela izingxoxo eziningi ngesikhathi esisodwa nge-multiplexing amaphakethe futhi isebenzisa iziteshi zokuxhumana ezibonakalayo.
I-X-25 inikeze izingxenye ezintathu eziyisisekelo zezinhlelo:
- Isendlalelo somzimba
- Ukulayishwa kokuxhumanisa kwedatha
- Isendlalelo sephakheji
I-X-25 ilandela i- OSI Reference Model , kodwa izingqimba ze-X-25 zifana nomcabango ongokwenyama, ungqimba wokuxhumeka kwedatha kanye nokwakheka kwenethiwekhi yesimo esijwayelekile se- OSI .
Ngenxa yokwamukelwa kwe- Intanethi ye- Intanethi (IP) njengendlela evamile kumanethiwekhi ezinkampani, izicelo ezingu-X.25 zathuthela ezixazululeni ezishibhile zisebenzisa i-IP njengendlela yokulandelana kwenethiwekhi yezokuxhumana nokufaka izendlalelo ezingezansi ze-X.25 nge- Ethernet noma nge-hardware entsha ye- ATM .