Specifications

Appendix C Operation, Administration, and Maintenance (OAM) Installation and Operation Manual
C-6 OAM Flows RICi-4E1/T1, RICi-8E1/T1 Ver. 2.0
The message is initiated by the local device and runs periodically making it
suitable for fault detection.
Unicast ETH-LB request message is sent from a MEP to a specific MEP (remote
device). The DA of the request message is a unicast MAC address of destination
device. Upon receipt of the request message, the MEP responds with unicast ETH-
LB reply message. The DA of the reply message is a unicast MAC address of
requesting device, learned from request message.
Continuity Check (ETH-CC)
Ethernet Continuity Check (ETH-CC) can be used to detect continuity failures
across flows between a given pair of edge service point on a flow. Continuity
failures are caused by:
• Major failures (link failure, device failure, network path failure etc)
• Minor failures (software failure, memory corruption, incorrect configuration
etc).
The ETH-CC signal is generated by one MEP. Upon receipt of the first ETH-CC
signal from a sending MEP, the receiving MEP detects continuity with sending MEP
and expects to receive further periodic ETH-CC signals. Once the receiving MEP
stops receiving periodic ETH-CC signals from sending MEP, it declares continuity
failure. The MEP that detects the continuity failure notifies the operator by
sending an alarm or a trap.
OAM Procedures
This section discusses the continuity check (CC) and the performance
measurement (PM) procedures.
Continuity Check Procedure
The loopback message and the ETH-CC messages are used for continuity check. In
case the services are defined and PM collection is enabled, they are also used to
carry PM messages. If PM collection is disabled, the messages are used for
continuity check only.
If the RX CC mode of the receiver is configured to CC-based, the continuity
detection is based on ETH-CC. If the mode is set to LB-based, the continuity
detection is based on ETH-LB. If the mode is disabled, the continuity detection is
not performed.
ETH-LB Method
The ETH-LB method includes the following elements:
• Unicast ETH-LB transmission
Unicast ETH-LB request message is transmitted by a MEP
(RICi-4E1/T1, RICi-8E1/T1) every second. The transmitted Transaction
Identifier is retained for at least five seconds after the unicast ETH-LB signal
is transmitted. The Transaction Identifier must be changed for every unicast
ETH-LB message, and no Transaction Identifier from the same MEP is allowed
to be repeated within 1 minute.