Operation Manual – Ethernet OAMH3C S9500 Series Routing Switches Chapter 1 Ethernet OAM Configuration1-4Processing capability Active DTE Passive DTESend variable response OAMPDUsYes, but the peerDTE is required tobe in the activemode.YesSend loopback control OAMPDUs Yes NoRespond to loopback control OAMPDUsYes, but the peerDTE is required tobe in the activemode.YesSend organization specific OAMPDUs Yes YesIf OAM configurations at both ends are consistent, OAM operation begins at the datalink layer.1.1.2 Link MonitorThrough link monitor, you can detect and find faults in various environments at the datalink layer. Link monitor uses event notification PDUs. When a link fault occurs, the locallink notifies the OAM entity of the fault after detecting the fault. The following tabledefines standard link events.Table 1-3 Standard link eventsStandard link events DefinitionError signal event The number of error signals within a fixed period oftime exceeds the defined threshold.Errored frame event The number of errored frames within a fixed periodof time exceeds the defined threshold.Errored frame period event The number of errored frames received within theperiod of N frames exceeds the defined threshold.Errored frame seconds event The number of error seconds within M secondsexceeds the defined threshold.802.3ah does not guarantee that all OAMPDUs can be sent successfully. An eventnotification OAMPDU should be sent multiple times to handle the packet loss situationand a counting sequence number is used to identify each OAMPDU to be sent.1.1.3 Diagnosing Remote FaultsEthernet faults are difficult to diagnose, especially when physical communication is stillmaintained but network performance is decreasing gradually. OAMPDU defines a flagto allow an OAM entity to send information to the peer. The flag defines an emergency
