Specifications

Appendix C Operation, Administration and Maintenance (OAM) Installation and Operation Manual
C-8 OAM Flows LA-210 Ver. 1.5
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 (LA-210) 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
LA-210 measures performance during 15-minute intervals. It also stores
performance history data of nthe last 24 hours (96 intervals).
Table C-2 lists the
PM counters supported by LA-210.
Table C-2. PM Counters
Parameter Description
Frames Above Delay Obj. Number of frames that exceeded delay objective
Frames Below Delay Obj. Number of frames below or equal delay objective
Frames Above DV Obj. Number of frames that exceeded delay variation objective
Frames Below DV Obj. Number of frames below or equal delay variation objective