FDDI 1 vs FDDI 2
Fiber Distributed Data Interface (FDDI) yog tus qauv xa tawm cov ntaub ntawv rau Local Area Networks (LAN) uas siv cov kab fiber ntau optic. Lub FDDI LAN tuaj yeem txuas mus txog 200 mais thiab nws tuaj yeem txhawb nqa ntau txhiab tus neeg siv. FDDI 1 raws tu qauv yog ua raws li cov txheej txheem token nplhaib. FDDI 2 yog qhov txuas ntxiv ntawm FDDI. Nws txuas ntxiv FDDI los ntawm kev ntxiv lub peev xwm los tswj lub suab thiab cov teeb liab video.
FDDI 1 yog dab tsi? (FDDI)
FDDI tseem hu ua FDDI 1, yog tus qauv kho qhov muag rau LANs raws li tus lej token nplhaib. Txawm hais tias lub hauv paus nruab nrab siv los ntawm FDDI yog optical fiber, nws kuj siv tau tooj liab. Nyob rau hauv xws li mob, nws yog hu ua CDDI (Copper Distributed Data Interface). FDDI network muaj ob lub nplhaib. Cov tsheb khiav ntawm txhua lub nplhaib ntws mus rau qhov sib txawv, uas yog hu ua counter rotating. Lub nplhaib thib ob ua raws li kev thaub qab yog tias lub nplhaib tseem ceeb ua tsis tiav. Vim li no, FDDI tes hauj lwm muab superior robustness thiab kev ntseeg tau. Lub peev xwm ntawm lub nplhaib tseem ceeb yog 100Mbps thiab yog tias lub nplhaib thib ob tsis siv rau kev thaub qab, nws tseem tuaj yeem nqa cov ntaub ntawv, uas ua rau tag nrho lub peev xwm ntawm lub network mus txog 200 Mbps. Txij li thaum FDDI txhawb nqa lub siab bandwidth thiab qhov kev ncua deb ntau dua li tooj liab, nws tau nquag siv los ua cov cuab yeej siv hluav taws xob ceev ceev. American National Standards Committee X3-T9 tsim FDDI thiab nws kuj ua raws li Open System Interconnect (OSI) qauv ntawm kev ua haujlwm txheej. FDDI kuj tseem siv tau los cuam tshuam LANs uas siv lwm cov kev cai. FDDI yog ib qho kev sau ntawm plaub qhov tshwj xeeb thiab txhua qhov kev qhia tshwj xeeb no muaj cov haujlwm tshwj xeeb. Thaum cov kev qhia tshwj xeeb no sib xyaw ua ke, lawv tuaj yeem muab kev sib txuas ceev ntawm cov txheej txheem sab saud xws li TCP / IP thiab IPX thiab tseem muaj xov xwm xws li fiber-optic cabling. Plaub qhov tshwj xeeb hauv FDDI yog Media Access Control (MAC), Physical Layer Protocol (PHY), Lub Cev-Medium Dependent (PMD) thiab Chaw Tswj Xyuas Chaw Nres Tsheb (SMT). MAC specification txhais li cas qhov nruab nrab nkag mus. PHY specification txhais cov haujlwm xws li cov ntaub ntawv encoding/decoding cov txheej txheem, clocking yuav tsum, thiab lwm yam. PMD qhia cov kis nruab nrab yam ntxwv. Thaum kawg lub SMT specification txhais qhov chaw nres tsheb configuration, nplhaib configuration thiab nplhaib tswj nta.
FDDI 2 yog dab tsi? (FDDI ii)
FDDI-2 yog tus txheej txheem thib ob ntawm FDDI. Nws yog kev txhim kho tsis ntev los no ntawm FDDI uas ntxiv lub peev xwm los tswj lub suab teeb liab thiab yees duab los ntawm kev ntxiv cov kev pab cuam uas tsim nyog hloov hluav taws xob rau lub network. Qhov no ua rau FDDI-2 zoo heev haum rau loj scale Internet Service Provider (ISP) Is Taws Nem qaum kev siv scenarios. Tsis tas li ntawd, FDDI-2 muaj hom kev ua haujlwm tshiab hu ua Hybrid Mode. Ntxiv rau asynchronous thiab synchronous hom thav ntawv, hybrid hom siv lub voj voog 125 microsecond los thauj isochronous tsheb.
Qhov txawv ntawm FDDI 1 thiab FDDI 2 (FDDI ii)
FDDI-2 yog lub cim thib ob ntawm FDDI. Qhov tseem ceeb sib txawv ntawm lawv yog tias, ntxiv rau tag nrho cov functionality FDDI muab, FDDI-2 muab lub peev xwm los lis lub suab teeb liab thiab yees duab. Txawm hais tias ob qho tib si FDDI thiab FDDI-2 khiav ntawm 100 Mbits / sec ntawm cov fiber ntau thiab thauj asynchronous thiab synchronous hom thav ntawv, FDDI-2 tuaj yeem thauj cov tsheb khiav isochronous siv cov qauv tsim tshiab hybrid. Ntxiv mus, FDDI thiab FDDI-2 chaw nres tsheb tuaj yeem ua haujlwm hauv tib lub nplhaib nkaus xwb hauv hom FDDI yooj yim.
