Ukuqonda iDP kunye nendlela eyahlukileyo ngayo kwi-TCP
Iprotagram yeDatagram Protocol (UDP) yaqaliswa ngowe-1980 kwaye yenye yeenkqubo ezinokudala zenethiwekhi ezikhoyo. I- OSI elula yokulandelelana kwendlela yokuthunyelwa kwezicelo zonxibelelwano zabaxhasi / iseva, isekelwe kwi- Intanethi ye-Intanethi (IP) , kwaye iyona enye ingundoqo kwi- TCP .
Inkcazo emfutshane ye-UDP inokuchaza ukuba yinto engathembekiyo xa kuthelekiswa ne-TCP. Nangona oko kuyiyo, kuba akukho naluphi na iphutha lokuhlola okanye ukulungisa ukubandakanyeka ekuhanjisweni kwedatha, kunjalo kwakhona ukuba kukho izicelo ezicacileyo zalo mgaqo-nkqubo ukuba i-TCP ayikwazi ukufana.
I-UDP (ngezinye izihlandlo ekuthiwa yi-UDP / IP) isetyenziswa rhoqo kwiinkqubo zeenkomfa zevidiyo okanye imidlalo yekhompyutha eyenziweyo ngokukodwa ekusebenzeni kwexesha langempela. Ukufezekiswa komsebenzi ophezulu, umgaqo-nkqubo uvumela amapakethi ngamnye ukuba ahlahlwe (kungabikho ukuzama) kunye neipakethi ze-UDP ezifunyenwe ngoluhlu oluhlukile kunokuba zithunyelwe, njengoko zichazwe ngumsebenzi.
Le ndlela yokuhambisa, xa kuthelekiswa ne-TCP, ivumela idatha engaphantsi kunye nokulibaziseka. Ekubeni iipakethi zithunyelwa kungakhathaliseki ukuba yintoni na, kwaye akukho naluphi na ukuphambuka ukuhlola okubandakanyekayo, kuphumela ekusebenziseni i- bandwidth engaphantsi.
Ngaba i-UDP ingcono kuneTCP?
Impendulo yalo mbuzo ixhomekeke kumongo ukususela ekubeni i-UDP ivumela ukusebenza okungcono, kodwa mhlawumbi umgangatho obi kakhulu, kuneTCP.
Umzekelo omhle wokuba i-UDP inokukhethwa ngaphezu kwe-TCP xa ifika kwisicelo esenza ngcono nge- latency encinane, njengokudlala kwe-intanethi, ukuxoxa ngevidiyo okanye ukuhanjiswa kwezwi. Iipakethi ziyakwazi ukulahleka, kodwa ngokubambezeleka kokuphela kokunciphisa umgangatho, akukho ukulahlekelwa kwexabiso elibonakalayo.
Ngokudlala kwe-intanethi, ukuhamba kwe-UDP kuvumela umdlalo ukuba uqhubeke nangona uxhumo lulahleka ngokukhawuleza, okanye ukuba ezinye iipakethi ziyancitshiswa ngenxa yezizathu. Ukuba kukho ukulungiswa kwephutha, ukuxhamla kuya kubakho ukulahleka kwexesha kuba iipakethi zizama ukungena kwakhona apho ziyeke khona ukwenza iziphene, kodwa akudingekile kwimidlalo yevidiyo ephilayo. Kuyafana nokusasaza ubomi.
Nangona kunjalo, isizathu sokuba i-UDP ayilunganga xa ifika kwiifayile zokutshintshwa kukuba ufuna yonke i fayile ukuze uyisebenzise kakuhle. Kodwa akukho nto ifuna ipakethi nganye yevidiyo okanye ividiyo ukuze ujabulele.
Bobabini i-TCP kunye ne-UDP kumgca we-4 wesimo se-OSI kwaye usebenze ngeenkonzo ezifana ne- TFTP , i-RTSP kunye ne- DNS .
DP Datagram
I-trafiki ye-UDP isebenza ngento ebizwa ngokuthi i-datagram, kunye nayo yonke into ebonisa idatha enye yomyalezo. Iinkcukacha zentloko zigcinwa kwii-bytes zokuqala ezisi-8, kodwa ezinye zithatha umyalezo.
Inxalenye nganye ye-UDP yomxholo wenkcazelo, echazwe apha, yi- bytes ezimbini:
- Inombolo yefowuni yomthombo
- Inombolo yesango lokufika
- Ubungakanani beDatagram
- Checksum
Izinombolo zee-port ze UDP zivumela izicelo ezihlukeneyo ukuba zigcine iziteshi zabo zedata, efana ne-TCP. Iintloko ze-port ze-UDP zii-bytes ezimbini ezide; Ngoko ke, izibalo zee-port ze-UDP ezisemthethweni ziqala ukusuka ku-0 ukuya ku-65535.
Ubungakanani bwedata ye-UDP buyibalo yenani leetayiti equlethwe kumacandelo nakumacandelo. Ekubeni ubude bentloko bubungakanani obuqingqiweyo, le nsimu ilandelela ngokufanelekileyo ubude beengxenye zeedatha ezichanekileyo (ngamanye amaxesha zibizwa ngokuba yi-payload).
Ubukhulu beedatharram zihluka ngoxhomekeke kwimeko yokusebenza, kodwa banokufikelela kuma-bytes angama-65535.
Iingxelo ze- UDP zikhusela idatha yesigidimi ekukhunguleni. Ixabiso le-checksum limela ikhowudi yeenkcukacha zedataji ebalwe kuqala ngumthumeli kwaye kamva ngummkeli. Ukuba umtsalane wodatha unganyanzeliswa okanye wonakaliswe ngexesha lokusasazwa, umgaqo-nkqubo we-UDP ufumanisa ukungabikho kokubala kokuhlola.
Kwi-UDP, ukuhlolisisa kukukhetha, ngokuchasene ne-TCP apho ukuhlolwa kwee-checksums kuyimfuneko.