Page 302 - Cloud computing: From paradigm to operation

1 Framework and requirements for cloud computing

3) The CSC accesses the primary CSP's catalogue of service offerings and selects one or some of the
services in the catalogue;
4) The primary CSP arranges the service selected by the CSC. The service may be provided by the
primary CSP, by (some of) the secondary CSP(s) or by a combination of these CSPs. The primary CSP
intermediates, aggregates and/or arbitrages the services (see clause 7.3). The CSC starts using the
service.

In practice, the actual process will be more complex. There are different ways for the CSC to use the services.
If the requested service is hosted in the primary CSP, the CSC may access to this service directly (in the case
of 4a)). If the requested service is offered by a secondary CSP, the CSC may access to the service in the
secondary CSP via the primary CSP (in the cases of 4b) and 4c)). In the latter case, the network conditions,
service characteristics and service agreement among the CSC, the primary CSP and the involved secondary
CSP should be considered in order that the CSC accesses to the service in an appropriate manner.

9 Functional requirements for inter-cloud
This clause describes the CSPs' capabilities necessary to support different inter-cloud computing patterns
described in clause 8.

The capabilities and the relevant requirements identified in this clause are complementary to the general
requirements applicable to a CSP involved in inter-cloud as specified in [ITU-T Y.3501].

9.1 SLA and policy negotiation

The SLA and policy negotiation capability deals with the matching made by a primary CSP between SLA
requirements of a CSC and the SLAs of secondary CSPs involved in the considered inter-cloud pattern. The
subject includes the QoS related aspects. This capability also deals with the negotiation of service
provisioning policies associated with the different CSPs involved in the inter-cloud pattern.
The SLA requirements (including QoS) of a CSC for a given cloud service are expected to be met by appropriate
interworking with selected CSPs, even in the event of service performance degradation or a disaster.
The SLA and policy negotiation capability is required to:

– be aware of the SLA information related to the QoS and performance aspects of the CSPs involved
in the inter-cloud using standard formats.

The SLA and policy negotiation capability is recommended to:
– allow comparing, negotiating and settling down service provisioning policies between multiple CSPs
(for example, based on the settlement, these CSPs may be considered as a trusted group for inter-
cloud support).
NOTE – In this clause, policy refers to a way for a CSP to provide services in terms of presumed reliability, including its
backup scheme and target service levels. The policy affects SLAs. Policies may be different among CSPs. Policies may be
negotiated beforehand and settled. This process is referred to as the policy negotiation.
9.2 Resource monitoring

The resource monitoring capability deals with the monitoring by the primary CSP of the resources of the
secondary CSPs and the status attributes of these resources (e.g., usage amount, performance and quality
aspects). The primary CSP collects and monitors the information from the secondary CSPs in a secure way.
By monitoring the secondary CSPs' resources status (e.g., availability and dead/alive status of machines) and
detecting service level performance degradation (in terms of delay and response time), the primary CSP can
initiate actions to maintain service availability with the help of other secondary CSPs.

The resource monitoring capability is recommended to:
– allow describing and expressing the resource information (e.g., resource type, configuration and
status) in a standard manner in order to be able to monitor these resources across multiple CSPs;

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