Huawei Quidway S3700 Series Configuration Manual page 163

Quidway S3700 Series Ethernet Switches
Configuration Guide - Reliability
mile. EFM OAM is a link-level OAM mechanism. The S3700 provides the following EFM OAM
functions:
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Each interface enabled with EFM OAM works in a certain mode. EFM OAM has two operation
modes: active mode and passive mode. OAM discovery and remote loopback are initiated only
by the interface in active mode.
Ethernet CFM
802.1ag, referred to as Connectivity Fault Management (CFM), defines the OAM function used
to detect the connectivity of the Ethernet bearer network.
Issue 01 (2011-10-26)
Peer discovery
When the EFM OAM function is enabled on an interface of the S3700 and the peer interface,
the two interfaces match their EFM OAM configurations by sending and responding to
OAM Protocol Data Units (OAMPDUs). If the EFM OAM configurations on both
interfaces match, the two interfaces start the EFM OAM handshake. During the handshake,
the two interfaces send OAMPDUs periodically to maintain the neighbor relationship.
Link monitoring
When an interface detects an errored frame event or an errored frame error seconds event,
the interface sends an OAMPDU to notify the peer device of the event.
– An errored frame event occurs when the number of errored frames detected on an
interface reaches or exceeds the specified threshold within a certain period.
– An errored code event occurs when the number of errored codes reaches or exceeds the
specified threshold within a certain period.
– An errored frame seconds occurs when that the number of errored frame seconds
detected on an interface reaches or exceeds the specified threshold within a certain
period.
The detection duration is measured in seconds. If at least one errored frame is detected
within a second, this second is called an errored frame second.
Fault notification
When an errored frame event or severe fault event occurs on the local device, the local node
sends fault notification messages to notify the peer device. At the same time, the local
device records the fault event in the log and reports the fault to the NMS. Fault events
include the following:
– System reboot
– Fault of a physical link
– Timeout of OAMPDUs
– Errors reported by the OAM module
When receiving the notification message, the peer records the event contained in the
message to the log and reports it to the NMS.
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4 Ethernet OAM Configuration
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