This is the default holding priority, 0 highest to 7 lowest, applied to LSPs that don't explicitly signal their own holding priority, determining how resistant an established LSP is to being preempted by a higher-priority LSP being set up later. A lower numeric value here means the LSP is harder to preempt once up and running, so an admin protecting a critical service's default LSPs from being displaced by newer, less important tunnels should set this to a low number like 0 or 1 rather than leaving it at a permissive default. For example, an LSP carrying a customer's premium SLA traffic defaulting to holding priority 0 would survive a resource crunch that ends up preempting other LSPs defaulting to holding priority 5 or 6.