Continuity Check Messages With Network Fault - FibroLAN Falcon Gen-3 M-Class User Manual

Falcon M-Class | User Guide
The Continuity Check is configured via the Functional Configuration
The drawing below shows the CCM Continuity Check Messages operation
Figure 4-185: Continuity Check Messages
4.22.6

Continuity Check Messages with Network Fault

The drawing below illustrates a fault in the network.
Figure 4-186: Continuity Check Messages with Network Fault
The fault in this case, is uni-directional or one way fault and its location is unknown.
MEPs notify each other of the faults they detect using the remote Defect indicator (RDI) flag in the
CCM message.
A MEP, upon detecting a fault condition, sets the RDI field in the CCM frame until the fault
condition is repaired. When a CCM frame is received, the MEP will examine it to verify that the
MEP sender belongs to its same domain level and that the RDI field is set.
Once the last unit on the right has not received 3 consecutive CCM messages, it will send an alarm
to the network manager and transmit CCM frames marked with RDI flag, notifying the remote MEP
receiving the CCM messages that there is a loss of service. The MEPs will try to allocate the fault by
using the Loopback and the Link Trace functions.
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