Specifications

Installation and Operation Manual Appendix C Operation, Administration and Maintenance (OAM)
LA-210 Ver. 1.5 OAM Flows C-5
used in cases where the MAC address of the destination MEP is not known.
Currently LA-210 supports point-to-point flows only.
OAM Message Association
On the receiver side the OAM frame is associated with a flow and a service.
Flow Association
When an OAM frame is associated with a flow, the following steps are performed:
• Request message reception
When a request message is received, the VLAN is extracted to find the Flow
ID. The Flow ID found at the receiver is compared against the Flow ID in the
frame. If the IDs are equal, further service association is made. If it is not
found, the “Flow ID no match” notification is returned in the reply message.
• Reply message reception
When a reply message is received, the VLAN is extracted to find the Flow ID.
The Flow ID found at the receiver is compared against the Flow ID in the
frame. If the IDs are equal, further service association is made. If it is not
found, the frame is discarded and connectivity alarm is issued.
Service Association
When an OAM frame is associated with a service, the following steps are
performed:
• Request message reception
The class of service characteristics are extracted from the frame and must be
matched to an entry in the flows <-> services table at the receiver. If they are
matched, the frame is processed. If not, the service ID is returned with the
“Not Found” notification.
• Reply message reception
The class of service characteristics are extracted from the frame and must be
matched to an entry in the flow <-> services table at the receiver. If they are
matched, the frame is processed. If not, the frame is discarded.
Ethernet Loopback (ETH-LB)
The ETH-LB can be used to verify connectivity. The ETH-LB is performed by
sending a request ETH-LB message to the remote unit and expecting an ETH-LB
reply message back to verify connectivity. When the insertion rate of ETH-LB
messages is much slower compared to data rate between the flow points, ETH-LB
is suitable to perform in-service connectivity verification and to measure round
trip delays.
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-