A read-only status string reporting the condition of the Contivity's demand interface subsystem, mostly reported as Healthy with a Disabled fallback. Demand interfaces bring up WAN links only when traffic requires them, so this status lets an admin confirm the feature is functioning before relying on it as a backup path. During a scheduled test of the backup dial path, the admin would first confirm demandintfServer shows Healthy rather than Disabled to ensure the interface can actually be brought up on demand.