Page 65 - Cloud computing: From paradigm to operation

Framework and requirements for cloud computing 1

Figure 7-4 illustrates the concepts of functions, layers and functional components.

Functional Layer Multi-layer
component functions

Functional Layer
component
Functional
component
Functional Layer
component

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Figure 7-4 – Functional layering

The cloud computing functional architecture is described in clause 9.1.

7.3.1 Functional components
A functional component is a functional building block needed to engage in an activity, backed by an
implementation.
The capabilities of a cloud computing system are fully defined by the set of implemented functional
components.
Functional components are further described in clause 9.2.

7.3.2 Functional layers
A layer is a set of functional components that provide similar capabilities or serve a common purpose.

The functional architecture is partially layered (i.e., has layers and a set of multi-layer functions).
There are four distinct layers defined in the CCRA:
• user layer, which includes functional components that support the cloud computing activities of
cloud service customers and cloud service partners;
• access layer, which includes functional components that facilitate function distribution and
interconnection;
• service layer, which includes functional components that provide the cloud services themselves
plus related administration and business capabilities, and the orchestration capabilities necessary
to realize them;
• resource layer, which includes the functional components that represent the resources needed to
implement the cloud computing system.

Note that not all layers or functional components are necessarily instantiated in a specific cloud computing
system.

7.3.3 Multi-layer functions

The multi-layer functions include functional components that provide capabilities that are used across
multiple functional layers.

Multi-layer functions are grouped into subsets.
The following subsets of multi-layer functions are defined:
• development support;
• integration;
• security systems;
• operational support systems;
• business support systems.

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