Switching yog ib lub ntsiab lus dav dav rau cov thev naus laus zis uas xa cov ntaub ntawv xa mus rau cov kev sib raug zoo uas ua tau raws li cov kev xav tau los ntawm kev siv phau ntawv lossis cov khoom siv tsis siv neeg raws li cov kev xav tau ntawm kev xa cov ntaub ntawv ntawm ob qhov kawg ntawm kev sib txuas lus. Raws li kev ua haujlwm sib txawv, nws tuaj yeem muab faib ua qhov dav hauv cheeb tsam network hloov thiab hloov chaw hauv cheeb tsam network. Kev hloov pauv ntawm thaj chaw dav dav yog ib hom khoom siv uas ua tiav cov ntaub ntawv sib pauv muaj nuj nqi hauv kev sib txuas lus. Yog li, dab tsi yog txoj kev xa mus rau qhov hloov pauv? Tom ntej no, cia peb ua rawsJHA Technologykom paub ntau ntxiv txog nws!

Txoj kev xa mus:
1. Txiav-los ntawm kev hloov
2.Kho-thiab-Forward switching
3.Fragment-dawb hloov

Kab lus no tsuas yog tsom rau thawj thiab thib ob txoj kev.

Ob qho kev txiav-los ntawm kev hloov pauv thiab kev hloov pauv hauv khw-thiab-rau pem hauv ntej yog L2 txoj kev xa mus, thiab lawv cov tswv yim xa mus yog raws li qhov chaw MAC (DMAC). Hauv qhov no, tsis muaj qhov sib txawv ntawm ob txoj kev xa mus.
Qhov sib txawv loj tshaj plaws ntawm lawv yog thaum lawv cuam tshuam nrog kev xa mus, uas yog, qhov hloov pauv cuam tshuam li cas nrog kev sib raug zoo ntawm cov txheej txheem tau txais thiab xa tawm ntawm cov ntaub ntawv pob.

Forwarding hom:
1. Txiav hla
Cut Through's Ethernet hloov tuaj yeem nkag siab tias yog kab matrix xov tooj hloov uas hla txhua qhov chaw nres nkoj. Thaum nws pom ib pob ntawv cov ntaub ntawv ntawm qhov chaw nres nkoj input, nws xyuas cov pob ntawv header, tau txais qhov chaw nyob ntawm pob ntawv, qhib lub rooj sab hauv dynamic lookup los hloov nws mus rau hauv qhov chaw tso zis sib xws, txuas ntawm kev sib tshuam ntawm cov tswv yim thiab cov zis, thiab hla cov ntaub ntawv pob ntawv ncaj qha mus rau qhov chaw nres nkoj sib txuas paub txog kev hloov pauv. Txij li thaum tsis muaj kev cia khoom yuav tsum tau, qhov ncua sij hawm me me thiab kev sib pauv tau nrawm heev, uas yog nws qhov zoo dua.

Nws qhov tsis zoo yog vim tias cov ntsiab lus ntawm cov ntaub ntawv pob ntawv tsis tau txais kev cawmdim los ntawm Ethernet hloov, nws tsis tuaj yeem kuaj xyuas seb cov ntaub ntawv xa mus tsis raug, thiab nws tsis tuaj yeem muab qhov yuam kev tshawb nrhiav. Vim tias tsis muaj qhov tsis sib xws, cov tswv yim / tso tawm cov chaw nres nkoj nrog cov nrawm sib txawv tsis tuaj yeem txuas ncaj qha, thiab cov pob ntawv poob tau yooj yim.

2. Khw-thiab-Forward switching
Txoj kev khw-thiab-rau pem hauv ntej yog txoj kev siv dav tshaj plaws hauv kev sib txuas hauv computer. Nws tshawb xyuas cov ntaub ntawv pob ntawv ntawm qhov chaw nres nkoj nkag, tshem tawm qhov chaw nyob ntawm pob ntawv cov ntaub ntawv tom qab ua tiav cov pob ntawv yuam kev, thiab hloov nws mus rau hauv qhov chaw tso tawm kom xa cov pob ntawv los ntawm lub rooj saib. Vim li no, txoj kev khw-thiab-mus tom ntej muaj qhov ncua sij hawm loj hauv kev ua cov ntaub ntawv, uas yog nws qhov tsis txaus, tab sis nws tuaj yeem ua qhov yuam kev ntawm cov ntaub ntawv pob nkag mus rau qhov hloov pauv thiab txhim kho kev ua haujlwm hauv network. Nws yog ib qho tseem ceeb tshwj xeeb uas nws tuaj yeem txhawb kev hloov pauv ntawm cov chaw nres nkoj sib txawv ntawm qhov sib txawv thiab tswj kev koom tes ntawm cov chaw nres nkoj siab ceev thiab cov chaw nres nkoj qis.

3. Fragment Dawb
Qhov no yog kev daws teeb meem ntawm thawj ob. Nws xyuas seb qhov ntev ntawm cov ntaub ntawv pob khoom puas txaus rau 64 bytes, yog tias nws tsawg dua 64 bytes, qhia tias nws yog pob ntawv cuav, ces muab pov tseg cov pob ntawv; yog tias nws loj dua 64 bytes, ces xa cov pob ntawv. Txoj kev no kuj tsis muab cov ntaub ntawv pov thawj. Nws cov ntaub ntawv ua ceev ceev yog ceev tshaj li khw-thiab-forward, tab sis qeeb dua ncaj-dhau.

Txawm hais tias nws yog kev xa mus ncaj qha lossis kev xa khoom xa mus, nws yog ob txheej txheej xa mus, thiab lawv cov tswv yim xa mus yog raws li qhov chaw MAC (DMAC). Tsis muaj qhov sib txawv ntawm ob txoj hauv kev xa mus rau qhov no. Qhov sib txawv loj tshaj plaws ntawm lawv yog thaum lawv tswj kev xa mus, uas yog, yuav ua li cas hloov pauv kev sib raug zoo ntawm cov txheej txheem tau txais thiab cov txheej txheem xa mus ntawm cov ntaub ntawv pob.