This read-only Counter64 is the current total number of packets lost on this specific underlying Path. An admin uses this per-path loss figure to isolate which physical route within a VPath is responsible when the VPath overall shows elevated loss. For example, discovering that nearly all of a VPath's packet loss is concentrated on one specific underlying path (say, the LTE-based one) tells the admin to focus remediation on that particular circuit rather than the whole virtual path.