Remote Discovery; Remote Loopback - Zte ZXR10 5900 Series User Manual

ZXR10 5900/5200 Series User Manual (Ethernet Switching Volume)
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Remote loopback

� Link monitor
DTE joining OAM sub-layer supports active/passive mode. When
enabling OAM, DTE that supports the two modes should select ac-
tive or passive.

Remote Discovery

OAM provides mechanism for detecting if remote DTE has OAM
sub-layer, if find it isn't satisfied, OAM client will know the result
and generate fail alarm. There are two cases for fail. One is that
peer end doesn't open OAM function, another is link connection
fault. During the remote discovery process, the information OAM-
PDU tag domain carries current link event (link fault, emergency
failure and emergency event). But the specific fault definition ,
composed of link fault, emergency failure and emergency event,
relates to implementation. So there are two ways to know link has
fault by remote discovery. One is knew by OAMPDU timeout, an-
other is to define some detailed emergency link events to let client
layer know which fault occurs on link from information OAMPDU.
The DTE which is configured active mode lauches discovery
process. When discovery process finishes, remote OAM peer en-
tity is in active mode, active DTE is allowed to send any OAMPDU,
DTE configured passive mode doesn't launch discovery process,
passive DTE feedbacks remote DTE launching discovery process.
Remote Loopback
OAM provides optional data link layer frame loopback mode. It is
controlled by the remote. OAM remote loopback is used for fault
location and link performance test. When remote DTE is in OAM
remote loop mode, local and remote DTE statistics can be querid
and compared at any time. Query can happen before , during
and after the process that loop is sent to remote DTE. In addition,
analyze OAM sub-layer loop frame to ensure additional information
about link health ( namely ensure frame dropping for link fault).
If an OAM client has sent a Loopback Control OAMPDU and is wait-
ing for the peer DTE to respond with an Information OAMPDU that
indicates it is in OAM remote loopback mode, and that OAM client
receives an OAM remote loopback command from the peer device,
the following procedures are recommended: a)If the local DTE has
a higher source_address than the peer, it should enter OAM remote
loopback mode at the command of its peer. If the local DTE has
a lower source_address than the peer, it should ignore the OAM
remote loopback command from its peer and continue as if it were
never received.