This is the hold-down time, in seconds (up to one hour), that the primary pseudowire must remain fault-free after recovering before the network automatically switches traffic back to it from the backup, a mechanism designed to prevent flapping back and forth if the primary path is intermittently unstable. A short revert time risks switching back onto a still-flaky primary path prematurely, while a long revert time means traffic stays on the possibly less optimal backup path longer than strictly necessary after the primary has genuinely recovered. If a service keeps bouncing between primary and backup shortly after each reversion, increasing this hold time is a standard remediation to avoid flapping.