When true, this makes the device advertise to its RSVP-TE neighbors, via the Restart_Cap object in Hello messages, that it supports graceful restart, the ability to preserve MPLS forwarding state across a control-plane restart. Advertising restart capability changes how neighbors behave when this device's RSVP-TE process restarts: instead of immediately tearing down LSPs on loss of Hello connectivity, a neighbor that saw this capability advertised will wait for this device to resynchronize. For example, if this is set to true but the device's control-plane software doesn't actually preserve forwarding state across a restart, neighbors would wait out the full restart-time value expecting a graceful resync that never occurs, delaying their own failure detection unnecessarily.