This object reports how long, in seconds, this router will wait without receiving a Hello packet across the sham link before declaring the far-end neighbor down, and per the description should be configured as a multiple of the Hello interval. It matters for tuning how quickly the router detects a failure in the underlying MPLS VPN path carrying this sham link versus how tolerant it is of transient packet loss; too short a dead interval on a sometimes-lossy VPN path can cause unnecessary adjacency flaps. An admin seeing frequent sham link flaps might deliberately lengthen this value if the underlying VPN transport occasionally drops a Hello or two without a real outage occurring.