User Manual
UMN:CLI
V8102
185
MEG Level
Eight MEG levels are available to accommodate different network deployment scenarios.
There are two cases based upon ETH layer encapsulation:
•
Shared MEG Levels
: Customer, provider, and operator share the MEG levels.
-
Customer role: Level 7, 6, 5
- Provider role: Level 4, 3
- Operator role: Level 2, 1
•
Independent MEG Levels
: Customer and provider do not share the MEG levels but
provider and operator share the MEG levels.
- Provider bridge: C-Tag, S-Tag
Fig. 7.3
Shared MEG Levels
Y.1731 Functions for Fault management
ITU-T Y.1731 OAM supports the following functions for fault management:
•
Ethernet Continuity Check (ETH-CC)
Each MEP sends periodic CCMs to other MEPs with a multicast destination address.
The loss of CCMs that ride along the data path would indicate a connectivity failure.
•
Ethernet Loopback (ETH-LB)
A LBM is sent to a unicast destination MAC address. MEP at the destination MAC
address responds to the LBM with an LBR. These messages are useful for verifying
connectivity with a specific L2 destination.
•
Ethernet Link Trace (ETH-LT)
ETH-LT function is used to retrieve adjacency relationship between a MEP and a
remote MEP or MIP.
•
Ethernet Alarm Indication Signal (ETH-AIS)
ETH-AIS is used to suppress alarms at the client layer following detection of defect
conditions at the server layer. Upon detecting a defect condition, the MEP start
transmitting periodic AIS frames at a configured client MEG level.
•
Ethernet Locked Signal (ETH-LCK)
ETH-LCK is used to communicate the administrative locking of a server layer MEP
and consequential interruption of data traffic forwarding towards the MEP expecting
the traffic.
