This specifies whether this dynamically-signaled tunnel imposes a fixed TTL on its MPLS label or inherits the TTL from the encapsulated frame, functioning identically to the same setting on static tunnels regardless of how the LSP itself was established. An admin sets this to fixed for the same core-hiding reason as on static tunnels, hiding the number of dynamically-selected hops (which can itself vary after a re-signal) from customer traceroutes. For example, a fixed TTL policy here means a customer's traceroute shows no core hops even after the tunnel silently re-signals over a path with a different hop count.