Page 835 - Cloud computing: From paradigm to operation

Intercloud and interoperability 5

7.3 Peer service integration

7.3.1 Peer CSP management
The peer CSP management function supports discovery of peer CSPs, negotiation with peer CSPs, primary
CSP role delegation, primary CSP switchover and switchback.
This function includes the following.
– Peer CSP discovery. This allows for exchanging of available inter-cloud service and resource
information between peer CSPs with peering, federation and intermediary patterns.
– Negotiation with peer CSPs. This allows for performing of API negotiation, SLA negotiation and policy
negotiation between peer CSPs.
NOTE 1 – API negotiation mainly deals with the API format, protocol, and content.
NOTE 2 – SLA negotiation deals with the different inter-cloud service quality between peer CSPs.
NOTE 3 – Policy negotiation with peer CSPs deals with policies that apply to inter-cloud services. Policies can include
business, technical, security, privacy and certification policies that apply to inter-cloud services and their usage by peer
CSPs.
– Primary CSP role delegation. This allows for identifying of peer CSPs that are capable of inheriting
the primary CSP role with peering, federation and intermediary inter-cloud patterns. This allows
negotiating with the peer CSPs identified as to whether they can accept the inheritance and also
allows for delegating of one of the peer CSPs identified to take the role of primary CSP.

– Primary CSP switchover and switchback. This allows for switchover of CSC access to a peer CSP
(acting as primary CSP) without service interruption for that CSC. This allows the CSC to use services
in a similar manner to the way they did before the access was switched over. This also allows for
switching back on CSC access to the primary CSP when this CSP has recovered from the reasons that
led to the switchover (e.g., a fault or load distribution).
NOTE 4 – Switchover conditions include load distribution between CSPs, in which the primary CSP role is maintained as
it is; and fault cases, in which the primary CSP role is delegated to the peer CSP (see clause 9.6 of [ITU-T Y.3511]).
NOTE 5 – The mechanism of switchover and switchback of a primary CSP can be a policy-based process.

7.3.2 Inter-cloud service negotiation
The inter-cloud service negotiation function negotiates inter-cloud service information, quality of service
(QoS), and performance estimation and selection policy between peer CSPs.
This function includes the following.
– Inter-cloud service information negotiation. This allows for negotiation of inter-cloud service
information between peer CSPs. Inter-cloud inter-working can only start when inter-cloud service
information negotiation is finalized and the inter-cloud service is available.

NOTE – The inter-cloud service information includes: inter-cloud service provider, inter-cloud service identifier, inter-
cloud service type, inter-cloud service status (available, reserved, allocated, released), inter-cloud service priority (high,
medium, normal, low).
– Inter-cloud service performance negotiation. This allows a primary CSP to negotiate with peer CSPs
in order to guarantee inter-cloud service performance that satisfies inter-cloud service SLAs.

– Inter-cloud service performance estimation and selection policy negotiation. This allows for
negotiating of inter-cloud service performance estimation and selection policies associated with
peer CSPs.
7.3.3 Inter-cloud service discovery

The inter-cloud service discovery function discovers available particular inter-cloud services between
peer CSPs.

This function includes the following.
– Inter-cloud service discovery. This allows for discovering of available particular inter-cloud services
provided by peer CSPs that meet the requirements of an inter-cloud service SLA.

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