Yintoni iProtocol ye-Spanning Tree?

IProtocol yeSpanning Tree, ngamanye amaxesha ibizwa nje ngokuba yi-Spanning Tree, yiWaze okanye iMaphuQuest yothungelwano lwale mihla lwe-Ethernet, isalathisa izithuthi ngeyona ndlela isebenzayo ngokusekwe kwiimeko zexesha lokwenyani.

Ngokusekwe kwi-algorithm eyenziwe ngusosayensi wekhompyuter waseMelika uRadia Perlman ngelixa wayesebenzela iDigital Equipment Corporation (DEC) ngo-1985, eyona njongo iphambili yeSpanning Tree kukuthintela amakhonkco angafunekiyo kunye nokuphoswa kweendlela zonxibelelwano kubume benethiwekhi obuntsonkothileyo.Njengomsebenzi wesibini, i-Spanning Tree inokuhambisa iipakethi kwiindawo ezinengxaki ukuqinisekisa ukuba unxibelelwano luyakwazi ukungena kuthungelwano olunokuthi lube nokuphazamiseka.

I-topology yoMthi eNabileyo ngokuchasene ne-Ring topology

Xa imibutho yayiqala ukuthungelanisa iikhomputha zayo ngeminyaka yoo-1980, olona lungelelwaniso ludumileyo yayiluthungelwano lweringi.Umzekelo, i-IBM yazisa itekhnoloji yeToken Ring yobunini kwi-1985.

Kwi-topology yenethiwekhi yeringi, i-node nganye idibanisa nezinye ezimbini, enye ehlala phambi kwayo kwiringi kwaye enye ibekwe emva kwayo.Iimpawu zijikeleza kuphela iringi kwicala elinye, kunye nenodi nganye ecaleni kwendlela inikezela ngayo nayiphi na kunye nazo zonke iipakethi ezijikelezayo kwiringi.

Ngelixa iinethiwekhi zeringi ezilula zisebenza kakuhle xa kukho iikhompyuter ezimbalwa kuphela, iiringi ziye zingasebenzi kakuhle xa amakhulu okanye amawaka ezixhobo zongezwa kuthungelwano.Ikhompyuter inokufuna ukuthumela iipakethi kumakhulu eendawo ukuze yabelane ngolwazi nenye inkqubo kwigumbi elikufuphi.I-Bandwidth kunye ne-throughput iphinda ibe yingxaki xa itrafikhi inokuhamba kwicala elinye kuphela, kungekho sicwangciso sokugcina ukuba i-node endleleni iyophuka okanye ixinanise kakhulu.

Kwi-90s, njengoko i-Ethernet yafumana ngokukhawuleza (i-100Mbit / sec. I-Fast Ethernet yaziswa ngo-1995) kunye neendleko zothungelwano lwe-Ethernet (iibhulorho, ukutshintsha, i-cabling) zaba zixabiso eliphantsi kakhulu kune-Token Ring, i-Spanning Tree iphumelele iimfazwe ze-LAN topology kunye noPhawu. Umsesane waphela ngokukhawuleza.

Usebenza Njani Umthi Obhadulayo

[BHALISA NGOKU kumsitho wokugqibela we-FutureIT wonyaka!Iworkshop yophuhliso lobuchwephesha olulodwa iyafumaneka.I-FutureIT eNew York, ngoNovemba 8]

I-Spanning Tree yiprothokholi yokudlulisela iipakethi zedatha.Yinxalenye enye ye-traffic cop kunye nenxalenye enye injineli yezothungelwano zeendlela ezihamba ngedatha.Ihlala kuLuhlu 2 (umaleko wekhonkco ledatha), ngoko ke ixhalabele ngokuhambisa iipakethe kwindawo yazo efanelekileyo, hayi ukuba luhlobo luni lweepakethi ezithunyelwayo, okanye idatha equlethwe yiyo.

I-Spanning Tree iye yanda kakhulu kangangokuba ukusetyenziswa kwayo kuchazwe kwiIEEE 802.1D umgangatho wothungelwano.Njengoko kuchaziwe kumgangatho, inye kuphela indlela esebenzayo enokubakho phakathi kwazo naziphi na iindawo ezimbini zokugqibela okanye izikhululo ukuze zisebenze ngokufanelekileyo.

I-Spanning Tree yenzelwe ukuphelisa ukuba kunokwenzeka ukuba idatha phakathi kwamacandelo enethiwekhi iya kuxinga kwi-loop.Ngokubanzi, iilophu zibhidanisa i-algorithm yokudlulisa efakwe kwizixhobo zenethiwekhi, iyenza ukuba isixhobo singasazi ukuba singathumela phi iipakethi.Oku kunokuba nesiphumo sokuphindwa kwezakhelo okanye ugqithiso lweepakethi eziphindiweyo kwiindawo ezininzi ekusingwa kuzo.Imiyalezo inokuphinda-phindwa.Unxibelelwano lunokubuyela emva kumthumeli.Inokuthi iphazamise inethiwekhi ukuba i-loops eninzi iqala ukwenzeka, isitya i-bandwidth ngaphandle kweenzuzo ezixabiswayo ngelixa uvimba ezinye iitrafikhi ezingafakwanga ukuba zidlule.

INkqubo yoMgaqo weMithi eNabileyokumisa amaqhina ekubeni enzengokuvala zonke ngaphandle kwendlela enye enokwenzeka kwipakethi yedatha nganye.Ukutshintshela kuthungelwano sebenzisa iSpanning Tree ukuchaza iindlela zeengcambu kunye neebhulorho apho idatha inokuhamba khona, kwaye isebenze ngokuvala iindlela eziphindwe kabini, zibenza zingasebenzi kwaye zingasebenzi ngelixa indlela yokuqala ikhona.

Isiphumo sesokuba unxibelelwano lwenethiwekhi luhamba ngaphandle komthungo nokuba luntsokothe ​​kangakanani okanye lukhulu kangakanani na uthungelwano.Ngandlel 'ithile, iSpanning Tree idala iindlela zothungelwano ukuze idatha ihambe kusetyenziswa isoftware ngendlela efanayo naleyo iinjineli zenethiwekhi zisebenzisa ihardware kuthungelwano oludala lwelophu.

IiNzuzo ezoNgezelelweyo zoMthi wokuNabula

Esona sizathu singundoqo sisetyenzisiweyo iSpanning Tree kukuphelisa ukuba nokwenzeka komzila wendlela ngaphakathi kuthungelwano.Kodwa zikho nezinye iingenelo.

Ngenxa yokuba i-Spanning Tree isoloko ikhangela kwaye ichaza ukuba zeziphi iindlela zothungelwano ezikhoyo kwiipakethi zedatha ukuhamba ngazo, inokubona ukuba indawo ehleli ecaleni kwenye yezo ndlela ziphambili ivaliwe.Oku kunokwenzeka ngenxa yezizathu ezahlukeneyo ukusuka kukusilela kwehardware ukuya kuqwalaselo olutsha lomsebenzi womnatha.Isenokuba yimeko yethutyana esekwe kwi-bandwidth okanye ezinye izinto.

Xa iSpanning Tree ifumanisa ukuba indlela yokuqala ayisasebenzi, inokukhawuleza ivule enye indlela ebikade ivaliwe.Inokuthi emva koko ithumele idatha ejikeleze indawo yengxaki, ekugqibeleni ikhethe indlela ejikileyo njengeyona ndlela intsha, okanye ithumele iipakethi kwibhulorho yokuqala ukuba inokuphinda ifumaneke.

Ngelixa i-original Spanning Tree yayikhawuleza ukwenza olo nxibelelwano lutsha njengoko lufuneka, ngo-2001 i-IEEE yazisa iProtocol ye-Rapid Spanning Tree Protocol (RSTP).Ekwabizwa ngokuba yinguqulo ye-802.1w yeprotocol, i-RSTP yenzelwe ukubonelela ngokukhawuleza ngokukhawuleza ekuphenduleni utshintsho lwenethiwekhi, ukuphuma kwesikhashana okanye ukungaphumeleli okucacileyo kwamacandelo.

Kwaye ngelixa i-RSTP yazisa indlela entsha yokuziphatha ehambelanayo kunye neendima zezibuko zebhulorho ukukhawulezisa inkqubo, kwaye yayiyilwe ukuba ibuyele umva ngokupheleleyo ihambelane noMthi wokuqala oPhumayo.Ke kuyenzeka ukuba izixhobo ezineenguqulelo zombini zeprotocol zisebenze kunye kuthungelwano olufanayo.

Iintsilelo zoMthi oQhubayo

Ngelixa i-Spanning Tree sele ikhona yonke indawo kwiminyaka emininzi emva kokusungulwa kwayo, kukho abo baphikisayo ukubaixesha lifikile.Esona siphoso sikhulu seSpanning Tree kukuba ivala iilophu ezinokuthi zibe kho kuthungelwano ngokuvala iindlela ezinokuhamba apho idatha inokuhamba.Kuyo nayiphi na inethiwekhi enikiweyo usebenzisa iSpanning Tree, malunga ne-40% yeendlela zothungelwano ezinokubakho zivaliwe kwidatha.

Kwiindawo zothungelwano ezintsonkothileyo kakhulu, ezifana nezo zifunyenwe kumaziko edatha, ukukwazi ukunyusa ngokukhawuleza ukuhlangabezana nemfuno kubalulekile.Ngaphandle kwemida ebekwe nguSpanning Tree, amaziko edatha angavula i-bandwidth eninzi ngaphandle kwesidingo se-hardware eyongezelelweyo yenethiwekhi.Olu luhlobo lwemeko ephoxayo, kuba iimeko zothungelwano ezintsonkothileyo yiyo loo nto yenziwa iSpanning Tree.Kwaye ngoku ukhuseleko olubonelelwa yiprothokholi ngokuchasene ne-loping, ngandlela thile, lubambe ezo ndawo zibuyayo kumandla azo apheleleyo.

Uguqulelo olusulungekileyo lweprothokholi ebizwa ngokuba yiMultiple-Instance Spanning Tree (MSTP) yaphuhliswa ukuze iqeshe iiLAN ezinenyani kwaye yenza ukuba iindlela ezininzi zothungelwano zivuleke ngexesha elinye, lo gama lusakhusela iilophu ekwenzeni.Kodwa nange-MSTP, iindlela ezimbalwa zedatha ezinokubakho zihlala zivaliwe kuyo nayiphi na inethiwekhi enikiweyo esebenzisa iprotocol.

Kubekho iinzame ezininzi ezingezizo ezisemgangathweni, ezizimeleyo zokuphucula imida ye-bandwidth yeSpanning Tree kule minyaka.Ngelixa abayili babanye babo baye babanga impumelelo kwiinzame zabo, uninzi aluhambelani ngokupheleleyo nomgaqo ongundoqo, okuthetha ukuba imibutho kufuneka iqeshe utshintsho olungamiselwanga kuzo zonke izixhobo zabo okanye ifumane indlela yokuzivumela ukuba zibekho nazo. iiswitshi eziqhuba umthi wokuSpanela osemgangathweni.Kwiimeko ezininzi, iindleko zokugcina nokuxhasa iincasa ezininzi zeSpanning Tree azifanelekanga.

Ngaba Umthi Onabileyo Uya Kuqhubeka Kwixesha Elizayo?

Ngaphandle kwemida kwi-bandwidth ngenxa ye-Spanning Tree yokuvala iindlela zenethiwekhi, akukho ngcinga eninzi okanye umzamo owenziweyo wokubuyisela iprotocol.Nangona i-IEEE ngamanye amaxesha ikhupha uhlaziyo ukuzama ukuyenza isebenze ngakumbi, zihlala zibuyela ngasemva zihambelana neenguqulelo ezikhoyo zeprotocol.

Ngandlela ithile, iSpanning Tree ilandela umthetho othi “Ukuba awophukanga, sukuyilungisa.”I-Spanning Tree ibaleka ngokuzimeleyo ngasemva kothungelwano oluninzi ukugcina itrafikhi ihamba, ukuthintela iilophu ezibangela ingozi ukuba zingenzeki, kwaye uhambisa itrafikhi kwindawo ezinengxaki ukuze abasebenzisi bokugqibela bangaze bazi nokuba amava abo enethiwekhi aphazanyiswa okwethutyana njengenxalenye yosuku ukuya- imisebenzi yosuku.Okwangoku, kwi-backend, abalawuli banokongeza izixhobo ezitsha kuthungelwano lwabo ngaphandle kokucinga kakhulu malunga nokuba baya kukwazi ukunxibelelana nenethiwekhi yonke okanye kwihlabathi langaphandle.

Ngenxa yayo yonke loo nto, kusenokwenzeka ukuba uMthi oSwineyo uya kuhlala usetyenziswa iminyaka emininzi ezayo.Kusenokubakho uhlaziyo oluncinci amaxesha ngamaxesha, kodwa iProtocol yeSpanning Tree kunye nazo zonke iimpawu ezibalulekileyo ezenzayo mhlawumbi zilapha ukuze zihlale.