TCP Amincewa da TCP
Dukkanmu mun saba da yarjejeniya ta TCP a matsayin abin da aka dawo da sufuri, amma ta yaya hakan zai tabbatar da amincin sufuri?
Don cimma nasarar watsa abubuwa, da yawa dalilai suna buƙatar la'akari, kamar su rashawa bayanai, asara, yin sharrints. Idan ba za a iya magance waɗannan matsalolin ba, ba za a iya samun baza abin dogaro ba.
Saboda haka, TCP tana aiki kamar lambar da aka lissafa, amsa da amincewa, sarrafa sarrafawa, sarrafa haɗin kai, da kuma sarrafa taga, da kuma sarrafa taga don cimma nasarar watsa.
A cikin wannan takarda, za mu mai da hankali ga taga rikewa, sarrafa gudanarwa da kuma magance matsalar TCP. Hanyar retransmation an rufe ta daban a sashi na gaba.
Hanyar Cibiyar sadarwa
Cibiyar gudummawar cibiyar sadarwa ko ka sani azaman hanyar zirga-zirgar ababen hawa alama ce mai ma'ana a tsakanin mahimmin dangantaka tsakanin masu samarwa da masu amfani. Wataƙila kun haɗu da wannan yanayin da yawa a wurin aiki ko a cikin tambayoyi. Idan ƙarfin mai samarwa don samar da ikon yin amfani da shi ya ci nasara, zai haifar da jerin gwano don su yi har abada. A cikin ƙarin hali mai mahimmanci, zaku san cewa saƙon zomo na zomo. Haka yake ga TCP; Idan ba a saka saƙonnin da ba a kula ba, za a saka saƙonni da yawa a cikin hanyar sadarwa, kuma masu sayen za su ci gaba da aika saƙonnin kwafi, wanda zai iya shafar aiwatar da hanyar sadarwa.
Don magance wannan sabon abu, TCP tana samar da tsarin mai aikawa don sarrafa adadin bayanan da aka aika dangane da ainihin karɓar karɓar karɓar karɓa, wanda aka san shi da kwarara mai gudana. Mai karɓar yana kula da karɓar taga, yayin da mai aikawa yana kula da taga sake aikawa. Ya kamata a lura cewa waɗannan windows ne kawai don haɗin TCP guda ɗaya ne kawai kuma ba duk haɗin suna raba taga ba.
TCP tana samar da iko na gudana ta hanyar amfani da canji don karɓar taga. The Recepetire taga yana ba da mai aikawa da nuni da sararin samaniya nawa har yanzu yake. Mai aikawa yana sarrafa adadin bayanan da aka aiko gwargwadon ƙarfin karbar mai karɓa.
Mai karɓar baƙi yana sanar da mai aiko da girman bayanan da zai iya karɓa, kuma mai aikawa ya aika zuwa wannan iyakar. Wannan iyaka shine girman taga, tuna da Shugaban TCP? Akwai wani kayan taga, wanda ake amfani dashi don nuna adadin bytes mai karba yana da iko ko kuma yarda.
Mai watsa shiri zai aika da fakiti na taga, wanda ake amfani dashi don gano ko mai karɓar mai karɓa har yanzu yana iya karɓar bayanai. Lokacin da Buffer na mai karɓa yana cikin haɗarin yawan ambaliya, an saita girman taga zuwa ƙaramin darajar don koyar da mai aikawa don sarrafa adadin bayanan da aka aiko.
Ga tashar hanyar sadarwa ta hanyar sadarwa:
Hanyar Conts
Kafin gabatar da iko na cunkoson, muna bukatar fahimtar cewa ƙari da taga, wanda aka yi amfani da shi don magance matsalar don karɓar taga don karɓar taga. Sabili da haka, ana kiyaye taga ta hanyar aika sakon TCP. Muna buƙatar algorithm don yanke shawara nawa ne abin da ya dace don aikawa, tunda aka aika da bayanai da yawa ko da yawa ba daidai bane, saboda haka manufar taga cunkoso.
A cikin kwararar cibiyar sadarwar da ta gabata, abin da muka guje wa shi ne mai aikawa yana cika bayanan mai karɓar tare da bayanai, amma ba mu san abin da ke faruwa a hanyar sadarwa ba. Yawanci, cibiyoyin sadarwa na kwamfuta suna cikin yanayin da aka raba. A sakamakon haka, za'a iya ɗaukar cunkoso na cibiyar sadarwa saboda sadarwa tsakanin sauran runduna.
Lokacin da aka cimon hanyar sadarwa, idan an ci gaba da aika da yawan fakiti masu yawa, yana iya haifar da matsaloli kamar jinkiri da asarar fakitoci. A wannan gaba, TCP za ta mayar da bayanan, amma retransphiplission zai kara nauyi a kan hanyar sadarwa, sakamakon ya haifar da mafi girma jinkiri da kuma karin asarar fakiti da kuma karin asarar fakiti. Wannan na iya shiga cikin m satar kuma ci gaba da samun girma.
Don haka, TCP ba ta iya watsi da abin da ke faruwa a hanyar sadarwa. Lokacin da aka tattara hanyar sadarwa, hadayun TCP da kanta ta rage yawan bayanan da ta aika.
Saboda haka, ana ba da shawarar ikon sarrafawa, wanda ke da nufin guje wa cika duk cibiyar sadarwar da bayanai daga mai aikawa. Don tsara adadin bayanan mai aikawa ya kamata ya aika, TCP yana ba da sanarwar ra'ayi da ake kira da taga cunkoson. Algorithm Controly Algorithm zai daidaita girman taga cunkoson-cunkoso bisa ga matakin congroon cibiyar sadarwar, don sarrafa adadin bayanan da mai aikawa.
Menene taga cunkoso? Menene wannan ya yi da taga Aika?
Titin conggrestoni ne mai canzawa ta hanyar mai aikawa wanda ke tantance adadin bayanan da mai aikawa zai iya aikawa. Canjin taga na ruwa da ke nazarin matakan cunkoson hanyar sadarwa.
Window ɗin aika aikawa ne a kan girman taga tsakanin mai aikawa da mai karɓa wanda ke nuna adadin bayanan mai karɓa zai iya karɓa. Taga cunkoson kuma taga aika aika; Tag ɗin aika aikawa yawanci daidai yake da mafi ƙarancin cunkoso da karɓar windows, windows ne, swnd = min (cwnd, rwnd).
Matsakaicin taga na CWNGENTESE kamar haka:
Idan babu cunkoso a cikin hanyar sadarwa, watau, babu komawar komputa na faruwa yana faruwa, taga cunkoso yana ƙaruwa.
Idan akwai cunkoso a cikin hanyar sadarwa, taga cunkoson ya ragu.
Mai aikawa ya yanke hukunci ko ana binne shi ta hanyar lura da ko fakiti ko fakiti na Ack Revelet a cikin lokacin da aka kayyade. Idan mai aikawa ya karbi fakitin itacen ack Recedket a cikin kayyade lokaci, ana ganin cibiyar sadarwa ta haduwa.
Baya ga taga cikawa, lokaci ya yi da za mu tattauna batun Controgithm na TCP. Algrognion Gudanar da TCP Algorithm ya ƙunshi manyan ɓangarorin uku:
Siyarwa Siyarwa:Da farko, window yakan koyi kadan ne, kuma mai aikawa yana ƙara taga cunkoson da ya dace don daidaitawa da sauri.
Cire Ciwon Kogin:Bayan taga cunkoson ya zarce da wani kofa, mai aikawa yana ƙara taga cunkoson-layi a cikin layi don rage girman ƙimar cunkoson da taga.
Mai sauri dawo:Idan cunkoso ya faru, mai aika halartar cikar taga da shiga da saurin murmurewa don tantance wurin da cibiyar sadakarwar da aka samu, sannan ya ci gaba da ƙara taga cunkoso.
Jinkirin farawa
Lokacin da aka kafa haɗin TCP, an saita crandarfin taga a farkon farawa zuwa mafi ƙarancin MSS (mafi girman sashi) darajar. Wannan hanyar, ƙimar aikawa ta farko ita ce game da MSS / RTT bytes / na biyu. Ainihin akwai bandwidth yawanci yafi girma fiye da MSS / RTT, don haka TCP yake so ya nemo ƙimar aikawa mafi kyau, wanda za'a iya samu ta hanyar jinkirin farawa.
A cikin jinkirin farawa, ƙimar cuttendy ɗin cuttend za a fara shi zuwa 1 mss, kuma kowane lokaci za a ƙara ƙimar fakitin da aka watsa, wato, ƙimar CWND zai zama 2 mss. Bayan haka, ƙimar CWND an ninka ninki biyu ga kowace nasara watsa ɓangaren ɓangaren fakiti, da sauransu. An nuna takamaiman tsarin ci gaban a cikin adadi mai zuwa.
Koyaya, ragin aikawa ba zai iya girma koyaushe ba; Ci gaban dole ne ya ƙare wani lokaci. Don haka, yaushe aikin aikawa ya ƙare? Sannu-lokaci-fara yawanci yana ƙare da karuwa a cikin adadin aika farashin a cikin ɗayan hanyoyi da yawa:
Hanya ta farko ita ce batun rashin barka da fakiti yayin aiwatar da jinkirin farawa. A lokacin da asarar fakiti ya faru, TCP ya kafa abin da ke tattare da Window ɗin da aka aika zuwa 1 kuma yana sake farawa da tsari mai saurin fara aiki. A wannan gaba, wani ra'ayi na jinkirin fara kofa na farawa SSthresh ne, darajar sa ta farko rabin darajar CWND wanda ke haifar da asarar fakiti wanda ke haifar da asarar fakiti wanda ke haifar da asarar fakiti. Wannan shine, lokacin da aka gano cunkoso, darajar SSthresh rabin darajar taga.
Hanya ta biyu ita ce don daidaitawa kai tsaye tare da ƙimar ƙarshen bakin lokacin ssthresh. Tunda darajar SSHRESH shine rabin darajar taga lokacin da ake gano cunkoso, asarar fakiti na iya faruwa tare da kowace gyara. Sabili da haka, ya fi kyau saita CWND zuwa SSthresh, wanda zai haifar da TCP don canzawa zuwa yanayin sarrafawa da ƙarshen jinkirin.
Hanya ta ƙarshe da fara farawa shine idan an gano ƙafafun kafa uku, TCP tana yin dawowa da sauri da shiga jihar dawo da kai. (Idan ba a bayyane yake ba me yasa akwai fakiti uku na koking ack ack ack ack ack ack act, za a yi bayanin wani daban a cikin kayan aikin sake.)
Cunkoso
A lokacin da TCP ya shiga cikin ikon sarrafa carar, an saita CWND zuwa rabin bakin kofa ciyawar SSthresh. Wannan yana nufin cewa darajar cwnd ba za a ninka sau biyu ba kowane lokaci ana karɓar sashin fakiti. Maimakon haka, ana ɗaukar kusancin ra'ayin mazan jiya wanda ƙimar CWND yake ƙaruwa da ɗaya Mss ɗaya kawai) Bayan an kammala ƙarshen fakiti ɗaya) bayan an gama magana. Misali, koda an yarda da sassan fakiti 10, darajar CWND zai karu ne kawai. Wannan samfurin haɓaka ne mai laushi kuma yana da iyaka akan girma. Lokacin da bashin fakiti ya faru, ƙimar CWND an canza zuwa MSS, kuma ƙimar SSthresh an saita zuwa rabin cwnd. Ko kuma zai dakatar da ci gaban MSS lokacin da aka karɓi martani na 3. Idan har yanzu an karɓi ƙafafun ƙafa uku bayan dakatar da ƙimar CWND, ƙimar SSthresh an yi rikodin rabin darajar CWND da kuma jihar dawo da sauri.
FASAHA
A cikin jihar dawo da sauri, darajar czgendon taga cwnd yana ƙaruwa ɗaya Mss ɗaya ga kowane ya karɓi sakin Ack, wato ack wanda bai isa cikin jerin ba. Wannan don yin amfani da sassan fakiti waɗanda aka yi nasara a cikin cibiyar sadarwar don haɓaka haɓaka haɓaka gwargwadon iko.
Lokacin da wani ɗakin wanka na kwandon ɓaukin bata ya isa, TCP ya rage darajar CWND sannan kuma shiga cikin jihar da ke nisanci. Wannan don sarrafa girman cirewar cunkoson kuma ku guji ƙara haɓakar hanyar sadarwa.
Idan lokacin da aka yi na faruwa ne bayan kammala ikon sarrafa carar gida, yanayin hanyar sadarwa ya zama mafi mahimmanci da TCP ta yi ƙaura daga jihar cunkoso ta guguwa ga jihar. A wannan yanayin, ƙimar congendon taga cwnd an saita zuwa 1 MST, Matsakaicin ɓangaren fakiti, kuma darajar jinkirin farawa zuwa rabin cwnd. Dalilin wannan shine a sake ƙara girman lokacin da keɓawa bayan cibiyar sadarwa ta murmura don daidaita farashin watsa hanyoyin don daidaita farashin watsa yanar gizon.
Taƙaitawa
A matsayin ingantacciyar hanyar sufuri, tcp tana da amincin sufuri ta hanyar lambar da lambar, amincewa, sarrafa returnationsiongissionaddamar, haɗin haɗi da sarrafa haɗi. Daga gare su, tsarin sarrafawa yana sarrafa adadin bayanan da aka aiko da mai aikawa gwargwadon karɓar hanyar karɓa, wanda ke guje wa matsalolin cunkoso na cibiyar sadarwa da lalata. Tsarin sarrafawa na congrestoni yana guje wa abin da ya faru na cunkoson hanyar sadarwa ta hanyar daidaita adadin bayanan da mai aiko. Abubuwan da ke tattare da taga da kuma aika da taga suna da alaƙa da juna, kuma adadin bayanan da ke aikawa ta hanyar gyara girman taga cunkoso. Slow farawa, cunkoso da sauri da kuma dawo da manyan sassan TCP Conrgithion ta hanyar dabarun daban-daban don daidaitawa da karfin cibiyar sadarwa da kuma dabarun sadarwa.
A gefe na gaba, za mu bincika hanyar dawo da TCP dalla-dalla. Hanyar Redransmation shine muhimmin bangare na TCP don cimma nasarar watsa abin dogara. Yana tabbatar da abin dogara da bayanai ta hanyar dawo da batattu, wanda aka lalata ko jinkirta bayanai. Ka'idar aiwatarwa da dabarun aiwatarwa za a gabatar da kuma bincika daki-daki a sashi na gaba. Kasance cikin damuwa!
Lokaci: Feb-24-2025
