CTRM in the Cloud
Public Cloud
A public cloud is a set of computers and computer network resources based on the standard cloudcomputing model, in which a service provider makes resources, such as applications and storage, available
to the public over the Internet. Public cloud services may be free or offered on a pay-per-usage model.
There are a growing number of global scale service providers (like Amazon, Microsoft or Google) who own
all infrastructures at their data center, as well as Cloud Brokers who aggregate infrastructure from multiple
providers.6
Private Cloud
Private cloud is cloud infrastructure operated solely for a single organization, whether managed internally or
by a third party, and located internally or externally at a third party datacenter. Undertaking a private cloud
project requires a significant level of engagement to virtualize the business environment, and requires the
organization to reevaluate decisions about existing resources. When done right, deploying a private cloud
can add value, but every step in the project raises security issues that must be addressed to prevent serious
vulnerabilities. Private clouds have attracted criticism because users "still have to buy, build, and manage
them" and thus do not benefit from less hands-on management, essentially "[lacking] the economic model
that makes cloud computing such an intriguing concept".7
Hosted
Hosted software refers to software that is installed, hosted and accessed entirely from a remote server or
location. While the term “hosted” is sometimes used synonymously with SaaS, we use it to mean single-tenanted
SaaS in which the client company is using its own instance of the application exclusively and accessing it via the
internet.
Application Service Provider (ASP)
In an ASP environment, the application software resides on an IT infrastructure that is owned or managed by
the software vendor and is accessed by licensed users through a web browser using HTML, or by special purpose
software provided by the vendor and residing on the users computers. Custom client software can interface to
these systems via XML APIs, providing integration with the clients’ in-house systems. ASPs may or may not use
multi-tenancy in the deployment of their software; some ASPs offer an instance or license to each customer (for
example using Virtualization), some deploy in a single instance multi-tenant access mode, now more frequently
referred to as "SaaS".
Leased
A commercial model, not specific to the method of software deployment, whereby the use of the application
software is paid for through periodic lease payments (generally monthly or annually). The software may actually
be delivered traditionally on-premises, hosted or SaaS. The lease fees are calculated based on any number of
formulae such as per user, per instance and so on.
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