802.3ah OAM Discovery

 

Discovery is the first phase of the 802.3ah protocol. During Discovery, local and remote units exchange Information OAM PDUs indicating capabilities and configuration information (mode, PDU size, loopback support, etc.). After successful negotiation the OAM protocol is enabled on the link. If no OAM PDU is received after 5 seconds, Discovery is restarted. The device can be configured in Active or Passive mode combinations.

 

 

Notice that each device can be placed in any mode as long as the remote and local device are not both in passive mode.

 

Discovery Capabilities: Capabilities advertised during discovery process

  • Remote Loopback

  • Link Events: Supported, but no stateful

  • MIB Retrieval: Can be advertised but is not supported in current release

  • Unidirection

 

Remote Loopback: The user can transmit a loopback command to place the remote unit into loopback mode. Every frame received is transmitted back on the same port to ensure the quality of links during installation or troubleshooting and for fault isolation testing.

 

Link Events: Event OAMPDU is transmitted when the link error exceeds the threshold. Events may be sent once or multiple times. In the current software release, link events are only transmitted upon user request, not based on threshold crossing.

 

MIB Retrieval: Retrieves information on network devices and interfaces.

 

Unidirection: Checks for unidirectional transmission.