Define the ATM 1 and ATM 2 OAM F5 Loopback Cell Period

For ATM 1 and ATM 2 interfaces with an ATM encapsulation, you can configure the OAM F5 loopback cell period on virtual circuits. This is the interval at which OAM F5 loopback cells are transmitted.

By default, no OAM F5 loopback cells are sent. To send OAM F5 loopback cells on a point-to-point interface, include the oam-period statement at the [edit interfaces interface-name unit logical-unit-number] hierarchy level:

[edit interfaces interface-name unit logical-unit-number] 

oam-period (disable | seconds); 

To send OAM F5 loopback cells on a virtual circuit that is part of a point-to-multipoint interface, include the oam-period statement at the [edit interfaces interface-name unit logical-unit-number family family address address multipoint-destination destination-address] hierarchy level:

[edit interfaces interface-name unit logical-unit-number family family address address 
multipoint-destination destination-address] 

oam-period (disable | seconds); 

The period can range from 1 through 900 seconds. You can also choose the disable option to disable the OAM loopback cell transmit feature.

OAM VC-AIS (alarm indication signal) and VC-RDI (remote defect indication) defect indication cells are used for identifying and reporting VC defects end-to-end. When a physical link or interface failure occurs, intermediate nodes insert OAM AIS cells into all the downstream VCs affected by the failure. Upon receiving an AIS cell on a VC, the router marks the logical interface down and sends an RDI cell on the same VC to notify the remote end of the error status. When an RDI cell is received on a VC, the router sets the logical interface status to down. When no AIS or RDI cells are received for 3 seconds, the router sets the logical interface status to up. You do not need to configure anything to enable defect indication.