Basic Concepts

The following ETH-OAM concepts help you understand the ETH-OAM function.

Location of the OAM Sub-layer in the OSI Reference Model

Figure 1 shows the location of the OAM sub-layer in the OSI reference model.

Figure 1 Location of the OAM sub-layer in the OSI reference model

The ETH-OAM is located in the data link layer of the OSI reference model, between the LLC sub-layer and MAC Control.

Location of the ETH-OAM in the Transmission Network Model

Figure 2 shows the location of the ETH-OAM in the transmission network model.

Figure 2 Location of the ETH-OAM in the transmission network model

ETH-OAM involves all layers above the MAC layer, covering a wide application range.

• Ethernet Service OAM
  The Ethernet service OAM function is maintained based on Ethernet service streams to provide automatic detection, fault location, and performance detection for the connectivity of Ethernet links. By using this function, you can maintain Ethernet Layer 2.
• Ethernet Port OAM
  The Ethernet port OAM is mainly used to automatically check the connectivity and performance and locate the faults of the physical links at the MAC layer and under the MAC layer. It is applicable when the physical Ethernet ports are directly connected.