Indicate the status of PVC link. Not Managed Down Verify loopback cells are sent at retry frequency to verify the VC is really down. After down-count unsuccessful retries, the VC goes to the down state (see definition of rc2kAtmPvcOamLoopbackDownCount). Down F5 OAM loopback cells. Up Verify End-to-end F5 OAM loopback cells are sent at retry frequency to verify the VC is really up. After up-count successive and successful loopback retries, the VC goes to the Up state (see definition of rc2kAtmPvcOamLoopbackUpCount). Up - End-to-end loopbacks are successful.