Ethernet alarm indication signal

Junos OS supports ITU-T Y.1731 Ethernet alarm indication signal function (ETH-AIS) to provide fault management for service providers. ETH-AIS enables you to suppress alarms when a fault condition is detected. Using ETH-AIS, an administrator can differentiate between faults at the customer level and faults at the provider level. When a fault condition is detected, a maintenance end point (MEP) generates ETH-AIS packets to the configured client levels for a specified duration until the fault condition is cleared. Any MEP configured to generate ETH-AIS packets signals to a level higher than its own. A MEP receiving ETH-AIS recognizes that the fault is at a lower level and then suppresses alarms at current level the MEP is in.

ACX Series routers support ETH-AIS PDU generation for server MEPs on the basis of the following defect conditions:

•  Loss of connectivity (physical link loss detection)
•  Layer 2 circuit or Layer 2 VPN down