各種ethoam對比ETHOAM所屬協(xié)議層次各個(gè)協(xié)議都屬于L2協(xié)議?！癓inkOAM”802.3ahisrunonapoint-to-pointL2Ethernetlink. Itisarequirementfortheaccesslink“ServiceOAM”CFM802.1ag/Y.1731isrunoveraL2Ethernetserviceend-to-end.ItcantraversemanyL2Ethernethops,butistunneledoverMPLSalongwiththeothercustomertrafficETHOAM，CFM以太網(wǎng)OAMOAM級以太網(wǎng)OAM鏈路級以太網(wǎng)OAM技術(shù)：也就是EthernetIEEE802.3ahUPE設(shè)備—CE測用戶網(wǎng)絡(luò)與運(yùn)營商網(wǎng)絡(luò)之間的鏈路狀態(tài)，保證用戶網(wǎng)絡(luò)和運(yùn)營商網(wǎng)絡(luò)的可靠性和穩(wěn)定性網(wǎng)絡(luò)級以太網(wǎng)OAMCF（ConnectivityFaultManagemenIEEE802.1ag障。圖1協(xié)議層次關(guān)系ETH作為一個(gè)二層協(xié)議，是監(jiān)控和解決網(wǎng)絡(luò)問題的工具。它能夠主要解決最后一公里Ethernet設(shè)備的OAM遠(yuǎn)MIB802.3ah還可以檢測以太網(wǎng)直連鏈路上的故障，尤其是運(yùn)營商接入用戶鏈路上的故障。OAMOAMMIB變量請求。以太網(wǎng)OAM是基于802.3鏈路對全雙工或模擬全雙工的點(diǎn)到點(diǎn)鏈路進(jìn)行管理的，它不支持諸如點(diǎn)到多點(diǎn)等共享鏈路的OAM過程。Customersite1Customersite1CE1PE1ProviderPE2CE2Customersite2圖2ETHOAM應(yīng)用場景3 802.3ah/802.1ag802.3ah的以太網(wǎng)OAM主要是鏈路方面的監(jiān)測和維護(hù)，是一種偏物理層的OAM，它主要應(yīng)用在網(wǎng)絡(luò)的邊緣設(shè)備上（接入層），且OAMPDU報(bào)文只能轉(zhuǎn)發(fā)一跳，主要用來監(jiān)測鏈路質(zhì)量、收集鏈路告警等。802.1agOAMOAM，主要用在匯聚層和核心層上，它的OAMPDU級快速倒換以及traceroute、pingA．802.3ah作為接入設(shè)備至局方邊緣網(wǎng)絡(luò)設(shè)備的鏈路檢測MAC層實(shí)現(xiàn)。ag實(shí)現(xiàn)基于VLANVLAN連接，可部署MEP。接入環(huán)網(wǎng)和匯聚環(huán)網(wǎng)上的設(shè)備可配置為MIP。若某段路徑上未配置VLAN連接，則該段路徑上不能配置802.1ag/Y.1731。4 802.1agY.1731的區(qū)別“ServiceOAM”IEEE802.1ag–“ConnectivityFaultManagement(CFM)”–usedoverEVC.MechanismsincludeContinuityCheck(CC)LoopbackLinktraceAlsoprovidestheabilitytomonitoratspecificservicelevels(includingcustomer,serviceprovider,operator,section)andsupportformaintenancedomains.ITU-T–“OAMFunctionsandMechanismsforEthernetbasednetworks”Providesallofthe802.1agfunctionalitywithadditionsincluding:DelayMeasurement(DM)DelayVariationMeasurement(DVM)LossMeas