The Information OAMPDU is transmitted by each peer at the configured intervals. This OAMPDU performs keepalive and critical notification functions. Various local conditions are conveyed through the setting of the Flags field. The following Critical Link Event defined in IEEE 802.3 Section 57.2.10.1 are supported:
Link Fault: the PHY has determined a fault has occurred in the receive direction of the local DTE
Dying Gasp: an unrecoverable local failure condition has occurred
Critical Event: an unspecified critical event has occurred
The local node can set an unset the various Flag fields based on the operational state of the port, shutdown or activation of the efm-oam protocol or locally raised events. These Flag fields maintain the setting for the continuance of a particular event. Changing port conditions, protocol state or operator intervention may impact the setting of these fields in the Information OAMPDU.
A peer processing the Information OAMPDU can take a configured action when one or more of these Flag fields are set. By default, receiving a set value for any of the Flag fields causes the local port to enter the previously mentioned Link Up port state and an event is logged. If this default behavior is not wanted, the operator may choose to log the event without affecting the local port. This is configurable per Flag field using the options under config>port>ethernet>efm-oam>peer-rdi-rx.