Specifications

Appendix C Operation, Administration, and Maintenance (OAM) Installation and Operation Manual
C-8 OAM Flows RICi-4E1/T1, RICi-8E1/T1 Ver. 2.0
ETH-CC Method
The ETH-CC method includes the following elements:
• ETH-CC transmission
Unicast ETH-CC request message is transmitted by a MEP (RICi-4E1/T1, RICi-
8E1/T1) every 1 second. The transmitted Transaction Identifier is retained for
at least 5 seconds after the unicast ETH-CC signal is transmitted. The
Transaction Identifier must be changed for every Unicast ETH-CC message,
and no Transaction Identifier from the same MEP is allowed to be repeated
within 1 minute.
• Unicast ETH-CC reply receipt
When a unicast ETH-CC message is received by a MEP (RICi-4E1/T1, RICi-
8E1/T1) diagnostic flow termination function, it examines the TLVs returned
in the unicast ETH-CC message, and declares the signal invalid if the TLVs do
not match those sent in the corresponding exiting MEP ID and Flow ID.
• Continuity declarations
Loss of Continuity and Connectivity Mismatch states are declared by the
ETH-CC mechanism.
 Loss of continuity declaration
When the MEP receives the ETH-CC message a timer is set with a
3.5 seconds timeout. If the source does send another message during
this period, the destination enters the loss of continuity state. Upon
receipt of the ETH-CC message, the destination resets the timer to
3.5 seconds. Regarding the continuity check message, the destination
check the Flow ID and the MEP ID. When the destination enters the loss
of continuity state, it adds 4 to the Unavailable Seconds counter. The
3.5 second period is calculated as a sliding window.
Loss of continuity state is cleared after 3.5 seconds with at least
2 messages from the source. In this case the Unavailable Seconds counter
is decreased by 4.
 Connectivity mismatch declaration
If the source Flow ID is not equal to the destination Flow ID for
10 consecutive times, the destination enters in to misconnection state.
Misconnection state is cleared after 10 consecutive reply messages with
the correct flow name from the source.
The Unavailable counter is maintained by the service according to the
number of PM messages that did not receive replies. If a mismatch
notification is received to the LB request, the frame is dropped and reply
message is not sent. This is why the service becomes unavailable (no
reply) in case of mismatch and the unavailable counter is raised.
Performance Measurement
RICi-4E1/T1, RICi-8E1/T1 measure performance in 15-minute intervals. The units
also store performance history data for the last 24 hours (96 intervals).
Table C-2
lists the PM counters supported by RICi-4E1/T1, RICi-8E1/T1.