Huawei NetEngine80E Configuration Manual - Reliability page 397

HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
EFM OAM
Ethernet in the First Mile (EFM) defined in IEEE 802.3ah specifies the physical layer
specifications and Ethernet OAM of the Ethernet for user access networks. It is used to detect
the last mile of the Ethernet link. EFM OAM is OAM at the link level.
EFM OAM supported by the NE80E/40E provides the following functions:
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Issue 02 (2011-09-10)
OAM discovery
When an interface on the NE80E/40E and the remote interface are both enabled with EFM
OAM, the interface and the remote interface send and respond with a slow protocol frame,
that is, an OAM Protocol Data Unit (OAMPDU) to determine whether the EFM OAM
configurations on both interfaces match. This is called OAM discovery. If the EFM OAM
configurations on both interfaces match, the two interfaces enter the EFM OAM Detect
state. In the Detect state, the two interfaces send OAMPDUs regularly to maintain
adjacencies. In normal situations, the interval for sending OAMPDUs is 1 second.
Link monitoring
Link monitoring is a mechanism for an interface to notify the peer of the fault by sending
the event notification OAMPDU when the interface detects the errored frame event, errored
code event, or errored frame seconds event.
– The errored frame event means that the number of errored frames detected on an
interface reaches or exceeds the specified threshold within a set period.
– The errored code event means that the number of errored codes detected on an interface
reaches or exceeds the specified threshold within a set period.
– The errored frame seconds summary event means that the number of errored frame
seconds detected on an interface reaches or exceeds the specified threshold within a set
period.
An errored frame second is a one-second interval during which at least one errored frame
is detected.
Fault notification
When a link event about a fault occurs on the local interface, the local interface notifies the
peer of the fault through OAMPDUs. The local interface then records the event in the log,
and reports the event to the NMS. This is called fault notification.
A link event can be one of the following:
– The system reboots.
– The Line Processing Unit (LPU) resets.
– A physical link fails.
– OAMPDUs time out.
– Errors transmitted by the OAM management module.
After receiving OAMPDUs, the peer records the event carried in OAMPDUs to the log and
reports it to the NMS.
Remote loopback
When the local interface sends non-OAMPDUs to the peer, instead of forwarding non-
OAMPDUs based on their destination MAC addresses, the peer loops back non-
OAMPDUs to the local interface. This is called remote loopback. Remote loopback can be
used to locate faults and test link performance.
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8 Ethernet OAM Configuration
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