Page 96 - Cloud computing: From paradigm to operation

1 Framework and requirements for cloud computing

connect various processing, storage and networking units in the physical resources so that together they
deliver an environment where NaaS, IaaS, PaaS or SaaS cloud service categories can be offered. The
controller might decide which CPUs and/or racks contain which virtual machines executing which parts of a
given cloud service's workload, and how such processing units are connected to each other, and when to
dynamically and transparently reassign parts of the workload to new units as conditions change.
The decision as to whether the physical resources are virtualized or not depends on the workload
characteristics to be run. For many cloud services' workloads (e.g., related to Compute as a Service and Data
Storage as a Service), it is convenient to virtualize the underlying physical resources, especially since
virtualization enables some scenarios which basically cannot be realized with a physical infrastructure (e.g.,
scenarios related to image management or dynamic scaling of CPU capacity as needed). For other workloads
(e.g., analytics and/or search) it is required to have maximum compute capacity and use hundreds or
thousands of nodes to run a single specialized workload. In such cases non-virtualized physical resources can
be more appropriate.

9.2.4.2 Physical resources
The physical resources functional component represents the elements needed by the cloud service provider
to run and manage the cloud services that they offer.

Physical resources include hardware resources, such as computers (CPU and memory), networks (routers,
firewalls, switches, network links and network connectors, storage components (hard disks) and other
physical computing infrastructure elements. These resources can include those that reside inside cloud data
centres (e.g., computing servers, storage servers, and intra-data centre networks), and those that reside
outside of data centres, typically networking resources, such as inter-data centre networks and core
transport networks.
All the elements of the physical resources are managed from the operational support systems functional
component, with the capability to place instances of each cloud service onto the resources as required to
satisfy customer requirements. Note that typically, the operational support systems functional component
itself runs on some part of the physical resources.

9.2.5 Multi-layer functions

9.2.5.1 Integration functional components
The integration functional components are responsible for connecting functional components in the
architecture to create a unified architecture. The integration functional components provide message
routing and message exchange mechanisms within the cloud architecture and its functional components as
well as with external functional components. Message routing can be based on various criteria, e.g., context,
policies.
The integration functional components include:
• security integration;

• monitoring integration;
• service integration;
• peer service integration.

9.2.5.1.1 Security integration
The security integration functional component provides integration to security capabilities including
authentication, authorization, encryption and integrity verification and to policy mechanisms that relate to
security capabilities.

9.2.5.1.2 Monitoring integration
The monitoring integration functional component provides connection from functional components in the
access layer, services layer and resource layer to the monitoring and reporting capabilities of the operational
support systems.

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