The Ethernet Remote Defect Indication function (ETH-RDI) is used by a MEP to communicate to its peer MEPs that a defect condition has been encountered. Defect conditions such as signal failure and AIS may result in the transmission of frames with ETH-RDI information. ETH-RDI is used only when ETH-CC transmission is enabled and it is enabled automatically.
ETH-RDI has the following two applications:
single-ended fault management — the receiving MEP detects an RDI defect condition, which gets correlated with other defect conditions in this MEP. The absence of received ETH-RDI information in a single MEP indicates the absence of defects in the entire MEG.
contribution to far-end performance monitoring — the transmitting MEP reflects that there was a defect at the far end, which is used as an input to the performance monitoring process
A MEP that is in a defect condition transmits frames with ETH-RDI information. A MEP, upon receiving frames with ETH-RDI information, determines that its peer MEP has encountered a defect condition.
The specific configuration information required by a MEP to support the ETH-RDI function is as follows:
MEG level — the MEG level at which the MEP exists
ETH-RDI transmission period — application-dependent and is the same value as the ETH-CC transmission period
priority — the priority of frames containing ETH-RDI information and is the same value as the ETH-CC priority
The PDU used to carry ETH-RDI information is the CCM.
When a port or interface experiences a failure, the Up MEP on the port or interface transmits a Port or Interface Status TLV (or both).
If the hold-mep-up-on-failure command is enabled:
the Up MEP indicates ETH-RDI
the remote MEP indicates a DefMACstatus
If the hold-mep-up-on-failure command is disabled:
the Up MEP indicates a DefRemoteCCM defect
the remote MEP indicates both a DefMACstatus and a DefRDICCM defect
The hold-mep-up-on-failure command is not supported for VPLS SAPs.