This indicates the type of resource protection as linkProtection(0) or nodeProtection(1). It distinguishes whether the bypass tunnel is engineered merely to route around a failed link, rejoining the primary path at the very next hop, versus around a failed node entirely, which must reroute at least two hops downstream to bypass the node and its links. For example, a bypass tunnel set to nodeProtection(1) would still successfully reroute traffic if the entire next-hop router crashed, whereas one set to linkProtection(0) would fail to protect against that same node failure since it only detours around the link itself.