Which component is required to enable resilience in a Server Edition deployment?

Resilience in Server Edition ensures continuity of service if the Primary Server fails. Option A, "Secondary Server," is the required component, acting as a failover system that takes over call processing and management if the Primary Server becomes unavailable. This setup is a key feature of Server Edition’s high-availability design. Option B (Expansion System) adds capacity but does not provide resilience. Option C (Voicemail Pro Server) enhances voicemail but isn’t tied to core resilience. Option D (Application Server) supports additional applications (e.g., one-X Portal) but isn’t required for failover.References: Avaya IP Office Server Edition Resilience Configuration Guide.