ITU-T K.131 PDF

This Recommendation provides principles and appropriate methods for the design of measures to prevent failures caused by soft errors to satisfy the reliability requirement for telecommunication equipment installed at telecommunications centres for carrier networks, including that in core networks (link and node) and access networks. The principle used to set reliability requirements is described, but the values related to the requirements lie outside the scope of this Recommendation.

A similar methodology for the design of equipment made from dedicated hardware that configures physical network function-based networks described in this Recommendation may be applied to equipment made from general-purpose hardware that configures virtual network function-based networks expected to be introduced in the future. However, the precise methodology is still under study at the time of approval.