ABSTRACT
Cloud user service quality risks potentially impact service reliability, latency, availability, or overall quality delivered to cloud service users. It is useful to factor risk causes into following: proximal risk causes are the immediate cause of risk event, and distal factors are the deeper and ultimate causes of a risk event, sometimes called root causes. The lost packet compensation algorithm on the user's device can produce degraded quality when it tries to conceal episodes of packet loss. There are seven fundamental differences between virtualized network function (VNF) and physical network function (PNF) deployments, each of which raises several risks: software is decoupled from hardware; shared compute, memory, storage, and networking infrastructure; automated resource and application life cycle management; automated network service life cycle management; dynamic operations; increasingly complex multivendor environment; and "virtualized" demark or reference point. The chapter discusses the highest-level role-based service quality risks per the European Telecommunications Standards Institute (ETSI) network functions virtualization (NFV) quality accountability framework (QAF).
