本文件从弹性的角度描述了NFV环境中端到端可靠性和软件升级的模型和方法。本文件的范围包括以下项目:研究NFV的可靠性评估模型，包括建模架构。研究NFV的可靠性和可用性方法。为这些方法开发可靠性评估模型，包括动态运行方面，如负载和寿命周期运行的影响。研究NFV软件升级期间的可靠性问题，并开发升级机制以提高恢复能力。制定指导方针，实现不同服务弹性的差异化。

The present document describes the models and methods for end-to-end reliability in NFV environments and software upgrade from a resilience perspective. The scope of the present document covers the following items:Study reliability estimation models for NFV including modelling architecture.Study NFV reliability and availability methods.Develop reliability estimation models for these methods, including dynamic operational aspects such as impact of load and life-cycle operations.Study reliability issues during NFV software upgrade and develop upgrade mechanisms for improving resilience.Develop guidelines to realise the differentiation of resiliency for different services.