114 • Bring Your Own Devices (BYOD) Survival Guide
instead purchasing IT “on-demand” as an organization consumes ser-
vices, unique requirements have arisen that organizations need to address
when contracting with cloud service providers (CSPs).
SELECTING A CLOUD SERVICE
e primary driver behind purchasing any new IT service is to eectively
meet a commodity, support, or requirement that the organization has.
Part of the analysis of that need or problem is determining the appropriate
solution. Choosing the cloud is only the rst step in this analysis. It is also
critical for organizations to decide which cloud service and deployment
model best meets their needs.
e National Institute of Standards and Technology (NIST) has dened
three cloud computing service models: Infrastructure as a Service,
Platform as a Service, and Soware as a Service.
ese service models can be summarized as follows:
1. Infrastructure: the provision of processing, storage, networking,
and other fundamental computing resources
2. Platform: the deployment of applications created using programming
languages, libraries, services, and tools supported by a cloud provider
3. Soware: the use of applications running on a cloud infrastruc-
Each service model oers unique functionality depending on the class
of user, with control of the environment decreasing as you move from
Infrastructure to Platform to Soware. Infrastructure is most suitable for
users like network administrators as organizations can place unique plat-
forms and soware on the infrastructure being consumed. Platform is most
suitable for users such as server or system administrators in development
and deployment activities. Soware is most appropriate for end-users since
all functionalities are usually oered out of the box. Understanding the
degree of functionality and what users will consume the services is critical
for organizations in determining the appropriate cloud service to procure.
NIST has also dened four deployment models for cloud services:
Private, Public, Community, and Hybrid. ese service deployments can
be summarized as follows: