Netiweki ya EPON itengera njira ya FTTB kupanga netiweki, ndipo gawo loyambira la netiweki ndi OLT ndi ONU.OLT imapereka madoko ochulukirapo a PON a zida zapakati zamaofesi kuti alumikizane ndi zida za ONU;ONU ndi zida zogwiritsa ntchito zomwe zimapereka deta yofananira ndi maulalo amawu kuti azindikire kugwiritsa ntchito kwa ogwiritsa ntchito.Kuti akwaniritse ntchito zosiyanasiyana, ogwiritsa ntchito osiyanasiyana ndi mautumiki osiyanasiyana amalembedwa ndi ma tag osiyanasiyana a VLAN kuti atumize mosabisa ku seva yolumikizirana, ndipo ma tag ofananira a VLAN amachotsedwa ndikutumizidwa ku netiweki ya IP kuti atumizidwe.
1. EPON network introduction
EPON (Ethernet Passive Optical Network) ndiukadaulo wapaintaneti womwe ukubwera.Imatengera kapangidwe ka point-to-multipoint, passive optical fiber transmission mode, yotengera nsanja ya Ethernet yothamanga kwambiri komanso gawo la TDM nthawi ya MAC (Media Access Control) njira yowongolera media., Ukadaulo wofikira pa Broadband womwe umapereka mautumiki osiyanasiyana ophatikizika.Zomwe zimatchedwa "passive" zimatanthawuza kuti ODN ilibe zipangizo zamagetsi zamagetsi ndi magetsi, ndipo imapangidwa ndi zipangizo zopanda kanthu monga optical splitters (Splitter).Imatengera ukadaulo wa PON mu gawo lakuthupi, imagwiritsa ntchito protocol ya Ethernet mugawo lolumikizana, ndikuzindikira mwayi wa Ethernet pogwiritsa ntchito mawonekedwe a topology a PON.Choncho, imaphatikiza ubwino wa teknoloji ya PON ndi teknoloji ya Efaneti: mtengo wotsika, bandwidth mkulu, scalability amphamvu, kusinthasintha ndi mofulumira utumiki kukonzanso, kugwirizana ndi Efaneti alipo, kasamalidwe zosavuta ndi zina zotero.
EPON imatha kuzindikira kuphatikiza kwa mawu, data, makanema ndi ntchito zam'manja.Dongosolo la EPON limapangidwa makamaka ndi OLT (optical line terminal), ONU (optical network unit), ONT (optical network terminal) ndi ODN (optical distribution network).lowani.
Zida zamagetsi zogwira ntchito zimaphatikizapo zida zapakati paofesi (OLT) ndi optical network unit (ONU).Optical Network Units (ONUs) amapatsa ogwiritsa ntchito mawonekedwe pakati pa data, makanema ndi ma telefoni network ndi PON.Ntchito yoyambirira ya ONU ndiyo kulandira chizindikiro cha njira ya kuwala ndikuyisintha kukhala mawonekedwe ofunikira ndi wogwiritsa ntchito (Ethernet, IP broadcasting, telefoni, T1 / E1, etc.).Zida za OLT zimalumikizidwa ndi netiweki ya IP core kudzera mu ulusi wa kuwala.Kumayambiriro kwa maukonde kuwala kupeza, Kuphunzira ake kufika 20km, amaonetsetsa kuti OLT akhoza akweza kwa chikhalidwe metro convergence mfundo kuyambira gawo loyamba la kuwala mwayi maukonde yomanga, potero wosalira zambiri dongosolo maukonde a mwayi maukonde convergence wosanjikiza ndi kupulumutsa. mphamvu.chiwerengero cha maofesi omaliza.Kuphatikiza apo, mawonekedwe amtundu waukulu, bandwidth yofikira kwambiri, kudalirika kwakukulu, komanso kuthekera kothandizira kwapaintaneti yautumiki wambiri wa QoS kumapangitsanso kusinthika kwa netiweki yolumikizira kukhala malo ogwirizana, osinthika, komanso ogwira ntchito bwino.
2. Mfundo yofunikira ya netiweki ya EPON
Dongosolo la EPON limagwiritsa ntchito luso la WDM kuti lizindikire kufalikira kwa fiber imodzi, pogwiritsa ntchito uplink 1310nm ndi downlink 1490nm wavelengths kutumiza deta ndi mawu, pamene ntchito za CATV zimagwiritsa ntchito 1550nm wavelength kunyamula.OLT imayikidwa kumapeto kwa ofesi yapakati kuti igawire ndikuwongolera kulumikizidwa kwa njirayo, ndipo imakhala ndi ntchito zowunikira, kuyang'anira ndi kukonza nthawi yeniyeni.ONU imayikidwa pambali ya ogwiritsa ntchito, ndipo OLT ndi ONU zimagwirizanitsidwa mu 1: 16 / 1: 32 mode kudzera pa intaneti yogawa mawonedwe.
Pofuna kulekanitsa zizindikiro za maulendo ozungulira a ogwiritsa ntchito angapo pamtundu womwewo, njira ziwiri zotsatirazi zochulukitsira zingagwiritsidwe ntchito.
1) Kutsitsa kwa data kumatengera ukadaulo wowulutsa.Mu EPON, njira yotumizira deta yotsika kuchokera ku OLT kupita ku ma ONU angapo imatumizidwa pogwiritsa ntchito kuwulutsa kwa data.Deta imawulutsidwa pansi kuchokera ku OLT kupita ku ma ONU angapo mu mawonekedwe a mapaketi akutali-kutalika.Phukusi lililonse lazidziwitso lili ndi mutu wa EPON, womwe umazindikiritsa mwapadera ngati paketiyo itumizidwa ku ONU-1, ONU-2 kapena ONU-3.Itha kudziwikanso ngati paketi yowulutsa kwa ma ONU onse kapena ku gulu linalake la ONU (mapaketi ambiri).Deta ikafika ku ONU, ONU imalandira ndikuzindikira mapaketi azidziwitso omwe amatumizidwa kwa iyo kudzera mu ma adilesi ofananira, ndikutaya mapaketi a chidziwitso omwe amatumizidwa ku ma ONU ena.ONU italembetsedwa kuti ikugwira ntchito, LLID yapadera imaperekedwa;OLT ikalandira deta, imafanizira mndandanda wa zolembera za LLID.ONU ikalandira deta, imangolandira mafelemu kapena mafelemu owulutsa omwe amafanana ndi LLID yake.
2) Kutsetsereka kwa data kumtunda kumatenga ukadaulo wa TDMA.OLT ikufanizira mndandanda wolembetsa wa LLID musanalandire deta;ONU iliyonse imatumiza mafelemu a data mu nthawi yofanana yoperekedwa ndi zida zapakati zaofesi OLT;nthawi yomwe yaperekedwa (kudzera muukadaulo woyambira) imalipira kusiyana kwa mtunda pakati pa ONU iliyonse ndikupewa kugundana kulikonse kwa ONU pakati.
https://720yun.com/t/d3vkbl8hddl?scene_id=86634935
https://www.smart-xlink.com/products.html