GE Multilin F650 - G.3 Link Loss Alert (LLA)

G-8 F650 DIGITAL BAY CONTROLLER GEK-106310-AF
G.3 LINK LOSS ALERT (LLA) APPENDIX G: REDUNDANCY PROTOCOL
G.3 Link loss alert (LLA)
G.3.1 LLA
(Link Loss Alert) operation: The operation of ports A and B are as follows:
Ports A and B use port A’s MAC and IP address settings while port B is in standby mode in that it does not actively
communicate on the Ethernet network but monitors its link.
G.3.2 LLA priority
If this setting is set to enabled, the port A has the priority. If PORTA’s LLA detects a problem with the link, communications is
switched to Port B. Port B is, in effect, acting as a redundant or backup link to the network for port A.
G.3.3 LLA timeout
This setting is active only when the LLA PRIORITY is set to ENABLED. When the link on primary port is detected again after it
fails, there is LLA TIMEOUT (ms) monitoring time for the health of the network. During this time, the secondary port remains
active. If primary network is healthy for more than LLA TOIMEOUT value, the switch over to primary port is automatic.
If the setting LLA PRIORITY is enabled:
• The primary port is port A while secondary (redundant) port is port B.
• The primary port is always used if available.
• If the link on primary port is lost switch over to secondary port occurs immediately.
• When the link on primary port is detected again, there is a monitoring timeout (LLA TIMEOUT) for the health of the
net
work. After that period the communication switch over to primary port automatically.
If the setting LLA PRIORITY is disabled:
• There is no priority, therefore there is no primary port. The communication switch over from one Port to the other
occurs when the link fails.
• In this case the LLA TIMEOUT setting does not act.