Zte ZXR10 5900E Product Description page 59


Remote loopback
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Link monitoring
DTE involved in OAM sub-layer supports active/passive mode. When OAM is
enabled, DTE that both modes support should choose active or passive.

Remote discovery
OAM provides a mechanism to check whether remote DTE has OAM
sub-layers. If discovery unsatisfied, OAM client learns that discovery is
unsuccessful; and generates discovery unsuccessful alarm. There may be two
reasons for unsuccessful discovery: one is that the peer-end doesn't start OAM;
the other is link connection failure. During the process of remote discovery,
label domain of OAMPDU message carries urgent link event (including link
failure, urgent failure and emergencies). But the particular failure definition of
link failure, urgent failure and emergencies are relevant to their implementation.
One way to learn about link failure via remote discovery is by OAMPDU timeout;
and the other way is to define some specific urgent link events to let client layer
to learn about link failure from OAMPDU.
DTE that configured with active mode launches the discovery process. Once
the discovery process is completed, when the counterpart entity connecting to
remote OAM is in active mode, active DTE is permitted to send any OAMPDU.
DTE that configured with passive mode doesn't launch discovery process. It
provides feedback of discovery process launched by remote DTE.

Remote loopback
OAM provides optional data link layer frame-level loopback mode controlled by
remote. OAM remote loopback can be applied for failure location and link
performance test. When remote DTE is in OAM remote loopback mode, the
statistic data of local and remote DTE can be queried and compared at any
moment. Query could be implemented before, during, or after loopback is sent
to remote DTE. Besides, OAM sub-layer loopback frame can be analyzed to get
additional information concerned link health (to determine frame dropping
caused by link failure).
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ZXR10 5900E Product Description
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