Alcatel-Lucent 7750 Configuration Manual page 161

Interface Configuration
===============================================================================
Cleared Degraded Ethernet OAM Event Logs
===============================================================================
Number of Logs : 0
===============================================================================
SRoS supports the vendor specific soft reset graceful recovery of efm-oam through the
configuration of grace-tx-enable under the config>system>ethernet>efm-oam and the
config>port>ethernet>efm-oam contexts. This feature is not enabled by default. When this
functionality is enabled the efm-oam protocol does not enter a non-operational state when both
nodes understand the grace function. The ports associated with the hardware that has successfully
executed the soft reset will clear all local and remote events. The peer that understands the
graceful restart procedure for efm-oam will clear all remote events that it received from the peer
that undergone the soft reset. The local events will not be cleared on the peer that has not
undergone soft reset. Again, the Information OAMPDU Flag fields are critical in propagating the
local event to the peer. Remember, the Event Notification OAMPDU will not be sent because it is
only sent on the initial raise.
In mixed environments where Link Monitoring is supported on one peer but not the other the
following behavior is normal, assuming the Information OAMPDU has been enabled to convey
the monitor fault event. The arriving Flag field fault will trigger the efm-oam protocol on the
receiving unsupportive node to move from operational to "send local and remote". The protocol
on the supportive node that set the Flag field to convey the fault will enter the "send local and
remote ok" state. The supportive node will maintain the Flag field setting until the condition has
cleared. The protocol will recover to the operational state once the original event has cleared;
assuming no other fault on the port is preventing the negotiation from progressing. If both nodes
were supportive of the Link Monitoring process, the protocol would remained operational.
In summary, Link monitors can be configured for frame and symbol monitors (specific hardware
only). By default, Link Monitoring and all monitors are shutdown. When the Link Monitoring
function is enabled, the capability (EV) will be advertised. When a monitor is enabled, a default
window size and a default signal failure threshold are activated. The local action for a signal
failure threshold event is to shutdown the local port. Notification will be sent to the peer using the
Event Notification OAMPDU. By default, the remote peer will not take any port action for the
Event Notification OAMPDU. The reception will only be logged. It is suggested the operator
evaluate the various defaults and configure the local-sf-action to set one of the Flag fields in the
Information OAMPDU using the info-notifications command options when fault notification to a
peer is required. Vendor specific TLVs and vendors specific OAMPDUs are just that, specific to
that vendor. Non-ALU vendor specific information will not be processed.
Capability Advertising
A supported capability, sometimes requiring activation, will be advertised to the peer. The EV
capability is advertisement when Link Monitoring is active on the port. This can be disabled using
7750 SR Interface Configuration Guide Page 161