Page 317 - Cloud computing: From paradigm to operation

Framework and requirements for cloud computing 1

Appendix III

Abstract service offering models for inter-cloud computing
(This appendix does not form an integral part of this Recommendation.)

This appendix describes several abstract service offering models relevant to inter-cloud computing and
provides supplementary information to the description provided in the main body of the Recommendation.
Inter-cloud computing performed over multiple CSPs allows a CSP (i.e., the primary CSP) to offer new services
with respect to expanded service items (cf. clause III.1) and enhanced service operations (cf. clause III.2).

III.1 Service item expansion

In terms of service variety, there are roughly two types of cloud expansions; one refers to adding more of the
same resources that the primary CSP already has, and the other refers to adding features based on the
resources that differ from those the primary CSP has.

Figure III.1 shows these two expansions.

CSC
CSC

Secondary CSP A

Primary CSP
CSP Secondary CSP B
a) Basic model – b) Volume expansion –
Two units are offered to a user. More than two units are offered beyond primary capacity.

CSC

Secondary CSP A

Secondary CSP B
Primary CSP
C) Service variety expansion –
Various units are offered beyond primary capability.

Y.3511(14)_FIII.1

Figure III.1 – Service item expansion – Volume and variety expansions in inter-cloud computing

In the basic model shown in Figure III.1-a, a single CSP offers a service consisting of two resource units. A
typical example of such a resource is a virtual machine (VM). The CSP by itself offers two VMs to a given CSC.
In the volume expansion shown in Figure III.1-b, two additional VMs are provided by the secondary CSPs A
and B. With their support, the primary CSP can offer a volume-expanded service, which now consists of four
VMs.

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