Yintoni imodeli ye-OSI kwaye yintoni umsebenzi wayo

Kwinqaku elilandelayo siza kujonga okusisiseko ukuba yintoni imodeli ye-OSI kunye nokuba yintoni umsebenzi wayo. bucala ngasekhohlo imodeli yereferensi yoQhagamshelwano lweeNkqubo eziVulekileyo (I-OSI, i-Open System Interconnection) yakhululwa ngo-1984, kwaye yayiyimodeli yenethiwekhi echazayo eyenziwe yi-ISO (Umbutho waMazwe ngaMazwe woLungiso). Imodeli ye-OSI ayikho enye into ngaphandle komgangatho wemigaqo yonxibelelwano. bomvu. Ezi protocols yimithetho yonxibelelwano esetyenziselwa ukuqhagamshela iikhompyuter ezimbini nangaphezulu. Yintoni eyenziwa yimodeli ye-OSI kukudibanisa ezi protocol zibe ngamaqela athile okanye iileya.

lo mgangatho ilandele injongo yebhongo yokudibanisa iinkqubo zemvelaphi eyahlukileyo, ukuze babenakho ukutshintshiselana ngolwazi ngaphandle kohlobo lwesithintelo., ngenxa yeeprothokholi ababesebenza ngazo ngokomenzi wazo. Imodeli ye-OSI yenziwe ngamanqanaba angama-7 okanye amanqanaba okutsalwa. Ngalinye kula manqanaba liya kuba nemisebenzi yalo, ukuze kunye bakwazi ukufikelela usukelo lwabo lokugqibela. Ngokuchanekileyo oku kwahlula kumanqanaba kwenza kube lula ukunxibelelana kweeprotocol ezahlukeneyo, ngokugxininisa imisebenzi ethile kwinqanaba ngalinye lokusebenza.

Njengoko benditshilo, umaleko ngamnye we-OSI imodeli inomsebenzi othile kwaye inxibelelana namaleko angentla nangaphantsi. Iiprothokholi ziya kuba noxanduva lonxibelelwano phakathi kwamaqela, ukuze a umkhosi inokunxibelelana neyohlukileyo, umaleko ngokomaleko.

Kufuneka kukhunjulwe ukuba i-OSI yimodeli yereferensi yethiyori, oko kukuthi, umgangatho oluncedo kwiinkqubo ezivela kubenzi abahlukeneyo kunye/okanye iinkampani ukunxibelelana ngokufanelekileyo. Inye into ekufuneka uyikhumbule kukuba imodeli yeOSI asiyonkcazelo ye ipolotiki okanye imodeli yenethiwekhi ngokwayo. Yintoni eyenziwa yi-OSI ngokwenene kukuchaza ukusebenza kwabo ukufikelela umgangatho.. Lo mzekelo awuchazi okanye uchaze iiprothokholi ezisetyenziswa kunxibelelwano, kuba ezi ziphunyezwa ngokuzimeleyo.

Iimaleko ezisi-7 zemodeli ye-OSI

Olu lwakhiwo lujongene nengxaki yonxibelelwano lwe-elektroniki kunye nendlela ye-7 yamanqanaba okanye amanqanaba. Olona lwazi luphezulu Uluhlu 7, kulapho usebenza khona idatha yesicelo, kwaye ezi zifakwe kwaye ziguqulwe de zifike kwi Uluhlu loku-1, okanye inqanaba elisezantsi, elilawulayo amasuntswana acocekileyo izakugqithiselwa kwindawo ebonakalayo (Iimpawu zombane, amaza erediyo, ukubethelwa kokukhanya...).

Ulwaleko olubonakalayo (Ye1)

Lo ngowona mgangatho uphantsi wemodeli ye-OSI, kwaye ikhathalela i-topology yenethiwekhi kunye noqhagamshelo lwehlabathi lwezixhobo kuthungelwano. Ibhekisa kokubini kwindlela ebonakalayo kunye nendlela ulwazi kunye nothungelwano olusasazwa ngayo. Inqanaba lomzimba okanye umaleko womzimba (Ye1) kulapho uguqulo olwenziwayo kulandelelwano lwamasuntswana ukuwahambisa ukusuka kwenye indawo ukuya kwenye lwenziwa.

Le Kapa Inoxanduva lokusasaza amasuntswana olwazi ngokusebenzisa indlela esetyenziselwa ukusasaza. Ikwajongene neempawu ezibonakalayo kunye neempawu zombane zamacandelo ahlukeneyo. Ukongeza, uya kuba ngumphathi wemiba yomatshini woqhagamshelo kunye neetheminali, kubandakanya nokutolikwa kwemiqondiso yombane/yombane.

Ulwaleko loMzimba (Ye1) unoxanduva lokudityaniswa kwezinto eziphathekayo kwinethiwekhi, zombini ngokwemiqathango ye indawo ebonakalayo (Amajelo eendaba akhokelwayo kunye nemidiya engakhokelwayo), e iimpawu eziphakathi (uhlobo lwekhebula okanye umgangatho walo; uhlobo lweziqhagamshelo ezisemgangathweni, njl ...) sele indlela yokuhanjiswa kolwazi.

Umaleko womzimba ufumana umlambo weebhithi kwaye uzama ukuwuthumela kwindawo ekuyiwa kuyo, kwaye akusiyo uxanduva lwayo lokuzinikezela ngaphandle kwempazamo, kuba olu xanduva luwela kuluhlu lwekhonkco lwedatha. Umaleko womzimba ibonelela ngeenkonzo kwikhonkco ledatha, ngenjongo yokuba ibonelele ngeenkonzo kumaleko womnatha.

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Umaleko weNxibelelaniso yeDatha (Uluhlu 2)

Le Kapa ijongene nokulungiswa kwendawo, ufikelelo oluphakathi, ubhaqo lwemposiso, unikezelo olucwangcisiweyo lwesakhelo, kunye nolawulo lokuhamba. Inoxanduva lokudluliselwa okuthembekileyo kolwazi ngesekethe yothumelo lwedatha. lo maleko ifumana izicelo kumaleko womnatha kwaye isebenzisa iinkonzo zomaleko womzimba.

Nayiphi na indlela yothumelo kufuneka ikwazi ukubonelela ngothumelo olungenaziphene, oko kukuthi, uhambo oluthembekileyo lwedatha kwikhonkco elibonakalayo. Ukufezekisa oku, kufuneka unyuse iibhloko zolwazi (ezibizwa ngokuba zizakhelo kulo maleko), banike idilesi yomaleko wekhonkco (I-Dirección MAC), lawula ukufunyanwa kwempazamo okanye ukulungiswa, kunye nokujongana nolawulo lokuhamba phakathi kwamaqela. Ke ngoko, olu maleko kufuneka ludale kwaye luqaphele imida yezakhelo, kunye nokusombulula iingxaki ezisuka ekuwohlokeni, ekulahlekeni okanye ekuphindaphindweni kwezi bhloko zolwazi.

Unokubandakanya ezinye indlela yolawulo lwendlela, ukuze kuthintelwe ukugcwala komamkeli ocothayo kunomthumeli.

Las imisebenzi ephambili yalo maleko Zizo: ukuqaliswa, ukupheliswa kunye nokuchongwa, ukwahlula kunye nokuthintela, i-octet kunye nongqamaniso lwabalinganiswa, ukucaciswa kwefreyimu kunye nokungafihli, ukulawula iimpazamo, ukulawula ukuhamba, ukubuyisela iimpazamo kunye nokulawula, kunye nokulungelelaniswa konxibelelwano..

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Ingubo yoMnatha (iNqanaba lesi-3)

Eli linqanaba okanye umaleko ukuba inikeza uqhagamshelwano kunye nokukhethwa kwendlela phakathi kweendlela ezimbini zokusingatha, enokuthi ibekwe kuthungelwano olwahlukileyo ngokwejografi. Iiyunithi zedatha zibizwa ngokuba ziipakethi, kwaye zingahlelwa ngokwemigaqo elandelwayo ekwazi ukusebenziseka kunye neendlela zokuziphatha. Unikezela ngeenkonzo kwinqanaba eliphezulu (umaleko wezothutho) kwaye ixhaswa ngumaleko wekhonkco lwedatha, oko kukuthi, sebenzisa imisebenzi yayo.

Umsebenzi oyintloko woluhlu lwekhonkco lwedatha kukuthatha ukuhanjiswa kwedatha kwaye uyiguqule ibe yimpazamo engenazo impazamo yoluhlu lwenethiwekhi.. Ifezekisa lo msebenzi ngokwahlula idata yegalelo kwidataframes (ukuba awuyi kuceba), kwaye idlulisela izakhelo ngokulandelelana ukuqhubekekisa ubume bezakhelo ezizithumelayo kwindawo ekuyiwa kuyo.

Ukuze wenze umsebenzi wakho, inganika iidilesi zothungelwano ezizodwa, qhagamshela iisubnets ezahlukeneyo, iipakethi zendlela, sebenzisa ulawulo lokuxinana kunye nolawulo lwemposiso..

Umsebenzi womnatha womnatha kukufumana idatha ukusuka kumthombo ukuya kwindawo ekuyiwa kuyo, naxa ezi zimbini zingadityaniswanga ngokuthe ngqo. Ii-routers zisebenza kulo maleko, nangona zinokuthi zisebenze njengoluhlu lwe-2 kwiimeko ezithile, kuxhomekeke kumsebenzi owabelwe kuwo. Yintoni egqithisile iifirewall zisebenza kulo maleko ikakhulu, ukulahla iidilesi zoomatshini.

Apha kwenziwa i idilesi enengqiqo yesixhobo setheminali, eyabelwe idilesi ye-IP.

Ezinye iiprothokholi zomaleko womnatha zezi: IP, OSPF, IS-IS, ICMP, ICMPv6, IGMP.

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Uluhlu lwezoThutho (iNqanaba lesi-4)

Le Kapa Inoxanduva lokuthutha idatha engenaziphene ukusuka kumatshini womthombo ukuya kumatshini wendawo., nokuba loluphi uhlobo lwenethiwekhi ebonakalayo oyisebenzisayo.

Injongo ephambili yoluhlu lwezothutho yi ukubonelela ngenkonzo esebenzayo nethembekileyo kubasebenzisi, ezizinkqubo zomaleko wesicelo. Ukufezekisa le njongo, olu luhlu lusebenzisa iinkonzo ezinikezelwa yi-network layer. I-hardware yothutho okanye isoftware ephethe uthutho ibizwa ngokuba iqumrhu lezothutho.

Lo ngumaleko wokuqala oqhuba unxibelelwano oluphela ukuya ekupheleni., kwaye le meko iya kuba sele igcinwe kwiindawo eziphezulu.

Umsebenzi wayo osisiseko kukwamkela idatha ethunyelwe ngamaleko angaphezulu, uwahlule ube ngamacandelo amancinci (ma candelo) ukuba kukho imfuneko, kwaye udlulisele kubo kumaleko womnatha. Kwimeko yomzekelo we-OSI, kwakhona kuqinisekiswa ukuba bafika ngokuchanekileyo kwelinye icala lonxibelelwano. Enye into ekufuneka uyiqaphele kukuba kufuneka ihlukanise iileya ezingaphezulu kuphumezo olunokwenzeka lwetekhnoloji yenethiwekhi kumaleko asezantsi.

kolu maleko iinkonzo zoqhagamshelo zibonelelwa ngoluhlu lweseshoni, oluya kuthi ekugqibeleni lusetyenziswe ngabasebenzisi benethiwekhi xa bethumela kwaye befumana iipakethi. I-Intanethi ineeprothokholi ezimbini eziphambili zothutho, enye i-connectless (UDP), kunye neyonxibelelwano-oriented (TCP). Ezi nkonzo ziya kudibaniswa nohlobo lonxibelelwano olusetyenzisiweyo, olunokuthi luhluke ngokuxhomekeke kwisicelo esenziwe kuluhlu lwezothutho.

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Uluhlu lweseshoni (iNqanaba lesi-5)

Uluhlu lweseshini luvela njengendlela yokulungelelanisa kunye nokuvumelanisa incoko kunye nokulawula utshintshiselwano lwedatha. Umsebenzi wayo kukulungelelanisa unxibelelwano phakathi kweenkqubo zombini zokugqibela., yiyo loo nto ikwabizwa ngokuba ngumaleko wonxibelelwano. Iseshoni ivumela uthutho oluqhelekileyo lwedatha, njengoko umaleko wezothutho usenza, kodwa ikwabonelela ngeenkonzo eziphuculweyo eziluncedo kwezinye izicelo.

Lo maleko ngowona ujongene nokugcina nokulawula ikhonkco esekwe phakathi kweekhompyuter ezimbini ezithumela idatha yalo naluphi na uhlobo. Yintoni egqithisile inikeza iindlela zokulawula incoko yababini phakathi kosetyenziso lweenkqubo zokugqibela.

iNqanaba lesi-5 eliseMpuma inikeza iinkonzo ezininzi ezibalulekileyo kunxibelelwano, njengoko zinjalo:

1. Ulawulo Lwengxoxo. Inokuba ngaxeshanye kumacala omabini (epheleleyo-kabini) okanye zitshintshwe kumacala omabini (isiqingatha-kabini)
2. Ulawulo lwamaqela. Ngale nto kuphunyezwa ukuba unxibelelwano ezimbini alwenziwa ngaxeshanye.
3. Ukubuyisela (iindawo zokujonga). Ezi zisebenza ukuze ukuba uphazamiseko lothumelo lwenzekile, lunokuqaliswa kwakhona ukusuka kwindawo yokugqibela yokuqinisekisa hayi ekuqaleni.

Ngoko ke, Inkonzo enikezelwa ngolu luhlu yikhono lokuqinisekisa ukuba, iseshoni esekwe phakathi koomatshini ababini, inokuqhutyelwa kwimisebenzi echazwe ukususela ekuqaleni ukuya ekupheleni, ukuyibuyisela kwakhona kwimeko yokuphazamiseka.. Kwiimeko ezininzi, iinkonzo zeeseshini zeseshini zixabisa ngokuyinxenye okanye ngokupheleleyo.

Iiprothokholi ezisebenza kumaleko weSeshini zezi: IProtocol yeRPC (umnxeba wenkqubo ekude), SCP (Khusela ikopi) kunye ne-ASP (Iseshini ye-APPLE TALK protocol).

Iifirewall zisebenza kulo maleko, ukuvala ufikelelo kumazibuko ekhompyuter.

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Uluhlu lwenkcazo-ntetho (iNqanaba lesi-6)

Injongo yoludwe lwenkcazo-ntetho kuku luthathele ingqalelo ukumelwa kolwazi, ukuze nangona iikhompyutha ezahlukeneyo zibe nokumelwa okwahlukileyo kwangaphakathi kwabalinganiswa (ASCII, Unicode, EBCDIC), amanani, isandi okanye imifanekiso, idatha ifika ngendlela eyaziwayo. Idatha ithuthwa ekuhlaleni kwiifomathi ezisemgangathweni

Le Kapa ngowokuqala ukusebenza ngakumbi kumxholo wonxibelelwano kunokuba kusekwe njani na. Ijongana nemiba efana ne-semantics kunye ne-syntax yedatha ethunyelwayo, kuba iikhompyuter ezahlukeneyo zinokuba neendlela ezahlukeneyo zokuziphatha.

Singawushwankathela lo maleko njengo onoxanduva lokuphatha izakhiwo zedatha engabonakaliyo, kunye nokwenza umboniso wedatha uguqulelo oluyimfuneko ukutolika okuchanekileyo okufanayo.. Ngamagama nje ambalwa, ngumguquleli.

Uluhlu lwesi-6 lunemisebenzi emithathu engundoqo. Le misebenzi yile: ukufomatha idatha, ufihlo lwedatha kunye noxinzelelo lwedatha.

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Uluhlu lweSicelo (iNqanaba lesi-7)

Lo maleko unikezela ngezicelo (umsebenzisi okanye hayi) la amathuba okufikelela kwiinkonzo zezinye iileya, kwaye ichaza iiprothokholi ezisetyenziswa zizicelo ukutshintshiselana ngedatha, njenge-imeyile (I-POP kunye ne-SMTP), abaphathi bedatabase okanye umncedisi wefayile (FTP). Zininzi iiprothokholi njengoko kukho izicelo ezahlukeneyo, kuba usetyenziso olutsha luphuhliswa rhoqo, inani leeprothokholi lihlala likhula.

Kulo maleko udibaniso lwamanye amanqanaba lusekiwe kwaye imisebenzi ilungiselelwe izicelo. Iqulethe usetyenziso olubonakalayo kumsebenzisi. Kufuneka kuqatshelwe ukuba umsebenzisi akaqhelekanga ukusebenzisana ngokuthe ngqo kwinqanaba lesicelo. Ngokuqhelekileyo isebenzisana neenkqubo ezithi zidibanise nenqanaba lesicelo.

Phakathi iiprothokholi eziqhelekileyo ezidumileyo ukuma:

1. http (IProtokhol yokuGqithisela umbhalo okhawulezileyo) ukufikelela kumaphepha ewebhu.
2. iftp (iProtocol yokuGqithisela iFayile) kugqithiso lwefayile.
3. I-SMTP (IProtokholi yokuDluliswa kweMeyile elula) ukuthumela nokusasaza ii-imeyile.
4. I-POP (IProtokholi yasePosini)/IMAP, yokufunyanwa kwe-imeyile.
5. I-SSHIndawo ekhuselekileyo) ikakhulu i-terminal ekude.
6. I-Telnet ukufikelela kwiikhompyuter ezikude. Nangona iye yawa ingasetyenziswa ngenxa yokungakhuseleki kwayo, ekubeni izitshixo zihamba zingafihlwanga kuthungelwano.

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Ngeenjongo ze Ukuququzelela ukufunda kunye nokunkqaya amagama amaleko enza imodeli ye-OSI, kukho umgaqo olula obandakanya ukubamba ngentloko njenge-mnemonic: I-FERTSPA. Oku ngesiNgesi kuya kuvakala kufana ne Okokuqala Spa (spa yokuqala kwiSpanish):

• Fngokwasemzimbeni
• Eikhonkco
• Red
• Tuthutho
• Sumboniso
• Pintetho
• Aisicelo

Ngamafutshane, kunokuthiwa I-OSI Stack yimodeli esekelwe kwii-7 iileya okanye amanqanaba okuthatha. Uluhlu ngalunye lunemisebenzi yalo, ukuba kunye luchaze umgangatho wonxibelelwano apho i-hardware kunye neeprotocol ezahlukeneyo zinokusebenzisana.