2N+1 is a redundancy configuration that provides two full, independent systems (2N) plus one additional spare unit, so redundancy is preserved even during maintenance of one system when a failure occurs in the active side. It offers the fault tolerance of 2N with extra margin, used for the most critical facilities where any degradation of protection is unacceptable.
Category: Resilience & Availability · Subcategory: Redundancy Topologies · Part of the AIDC Technical Terminology reference.