LECTURE 6

NIST CLOUD COMPUTING REFERENCE MODEL

• The NIST cloud computing definition is widely accepted and valuable in providing a clear understanding of cloud computing technologies and cloud services.The NIST cloud computingreference architecture presented in this section is a natural extension to the NIST cloud computing definition. 

• The NIST cloud computing reference architecture is a generic high-level conceptual model that is a powerful tool for discussing the requirements, structures, and operations of cloud computing.The model is not tied to any specific vendor products, services, or reference implementation, nor does it define prescriptive solutions that inhibit innovation. 

• It defines a set of actors, activities, and functions that can be used in the process of developing cloud computing architectures, and relates toa companion cloud computing taxonomy.It contains a set of views and descriptions that are the basis for discussing the characteristics, uses,and standards for cloud computing.

• The NIST cloud computing reference architecture focuses on the requirements of what cloud service provides, not on a design that defines a solution and its implementation. It is intended to facilitate the understanding of the operational intricacies in cloud computing. The reference architecture does not represent the system architecture of a specific cloud computing system;instead, it is a tool for describing, discussing, and developing the system-specific architecture using a common framework of reference.

•  The design of the NIST cloud computing reference architecture serves the objectives to: illustrate and understand various cloud services in the context of an overall cloud computing conceptual model; provide technical references to USG agencies and other consumers to understand, discuss,categorize, and compare cloud services; and communicate and analyze security, interoperability, and portability candidate standards and reference implementations. 

1. cloud consumer

1. cloud provider

1. cloud auditor

1. cloud broker

1. cloud carrier 

OVERVIEW 

The Overview of the Reference Architecture describes five major actors with their roles and responsibilities using the newly developing Cloud Computing Taxonomy.

The NIST cloud computing reference architecture defines five major actors: 

Interactions  between  the  Actors  in  Cloud  Computing

figure shows  the  interactions  among  the actors  in  the  NIST  cloud  computing  reference  architecture.  A  cloud  consumer  may  request  cloud services from a cloud provider directly or via a cloud broker. A cloud auditor conducts independent audits and may contact the others to collect necessary information. The details will be discussed in the following sections and be presented as successive diagrams in increasing levels of detail.

 
Example Usage Scenario 1

A cloud consumer may request service from a cloud broker instead of contacting a cloud provider directly. The cloud broker may create a new service by combining multiple services or by enhancing an existing service.In this example, the actual cloud providers are invisible to the cloud consumer and the cloud consumer interacts directly with the cloud broker. 

Example Usage Scenario 2

Cloud carriers provide the connectivity and transport of cloud services from cloud providers to cloud consumers.  As illustrated in Figure 4, a cloud provider participates in and arranges for two  unique service level agreements (SLAs), one with a cloud carrier (e.g. SLA2) and one with a cloud consumer (e.g. SLA1). A cloud provider arranges service level agreements (SLAs) with a cloud carrier and may request dedicated and encrypted connections to ensure the cloud services are consumed at a consistent level according to the contractual obligations with the cloud consumers.In this case, the provider may specify its requirements on capability, flexibility and functionality in SLA2 in order to provide essential  requirements in SLA1. 

Example Usage Scenario 3

For a cloud service, a cloud auditor conducts independent assessments of the operation and security of the cloud service implementation.The audit may involve interactions with both the Cloud Consumer and the Cloud Provider.