Cisco Systems A9014CFD manual OAM Features, Benefits of Ethernet OAM, 10-33

Chapter 10 Configuring Ethernet OAM

Ethernet OAM has two major components:

•The OAM client establishes and manages Ethernet OAM on a link and enables and configures the OAM sublayer. During the OAM discovery phase, the OAM client monitors OAM PDUs received from the remote peer and enables OAM functionality. After the discovery phase, it manages the rules of response to OAM PDUs and the OAM remote loopback mode.

•The OAM sublayer presents two standard IEEE 802.3 MAC service interfaces facing the superior and inferior MAC sublayers. It provides a dedicated interface for the OAM client to pass OAM control information and PDUs to and from the client. It includes these components:

–The control block provides the interface between the OAM client and other OAM sublayer internal blocks.

–The multiplexer manages frames from the MAC client, the control block, and the parser and passes OAM PDUs from the control block and loopback frames from the parser to the subordinate layer.

–The parser classifies frames as OAM PDUs, MAC client frames, or loopback frames and sends them to the appropriate entity: OAM PDUs to the control block, MAC client frames to the superior sublayer, and loopback frames to the multiplexer.

Benefits of Ethernet OAM

Ethernet OAM provides the following benefits:

•Competitive advantage for service providers

•Standardized mechanism to monitor the health of a link and perform diagnostics

OAM Features

The following OAM features are defined by IEEE 802.3ah:

•Discovery

•Link Monitoring

•Remote Failure Indication

•Remote Loopback

Discovery

Discovery is the first phase of Ethernet OAM and it identifies the devices in the network and their OAM capabilities. Discovery uses information OAM PDUs. During the discovery phase, the following information is advertised within periodic information OAM PDUs:

•OAM mode—Conveyed to the remote OAM entity. The mode can be either active or passive and can be used to determine device functionality.

•OAM configuration (capabilities)—Advertises the capabilities of the local OAM entity. With this information a peer can determine what functions are supported and accessible; for example, loopback capability.

•OAM PDU configuration—Includes the maximum OAM PDU size for receipt and delivery. This information along with the rate limiting of 10 frames per second can be used to limit the bandwidth allocated to OAM traffic.

•Platform identity—A combination of an organization unique identifier (OUI) and 32-bits of vendor-specific information. OUI allocation, controlled by the IEEE, is typically the first three bytes of a MAC address.

	Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
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