Page 564 - Cloud computing: From paradigm to operation

3 XaaS

7 DaaS general requirements

The DaaS general requirements are described in [ITU-T Y.3501] as follows:
• Quality of experience (QoE);
• Fast boot-up time;
• Configurability of the virtual environment;
• Single sign-on access control.

Additional general requirements of DaaS derived from use cases (cf. Appendix III) include (but are not
limited to):
• Support for high-definition (HD) and three-dimensional (3D) applications: DaaS can optionally
support execution of HD applications on virtual desktops for CSCs.

NOTE 1 – HD and/or 3D applications (e.g., high-definition 3D videos or games) are becoming one of the major
user demands in the personal computing device market.
• Extensible storage: It is recommended that a CSP support the storage extension requested by a CSC.
• Response time: It is recommended that DaaS provide CSCs with acceptable QoE.
NOTE 2 – Detailed relevant information on acceptable response time is described in Appendix IV.

• High availability: It is recommended that high availability in terms of delivery and operation of DaaS
be assured by a CSP.
• Resiliency to disaster: In a case of a disaster, DaaS is recommended to provide and maintain an
acceptable level of service.
NOTE 3 – This includes preserving the system information and the users' data including their virtual desktop
state such as power-on, power-off, suspend, etc.
• Service continuity: It is recommended that in case of temporarily unavailable resource access, a CSP
provides the capability to preserve the state of the user session.
• System scalability: It is recommended that DaaS supports elastic scalability of:
– Storage for DaaS user account information, virtual desktop environment settings, and active
and inactive virtual desktop environments;
– Processing and network capacity for the number of concurrent DaaS user connections and total
DaaS users;

– Underlying DaaS resources.
• DaaS developer environments: It is recommended to provide a developer environment for the
service and contents regarding DaaS.
• Diversity of DaaS client: It is recommended that the CSP support a wide selection of DaaS clients.
NOTE 4 – Examples of such DaaS clients are described in Appendix II.

8 DaaS functional requirements

8.1 Operation and management requirements
Operation and management requirements include:
• Unified management interface: It is recommended that the CSC be capable of deploying,
configuring, managing and monitoring the DaaS through a unified management interface.
• User account provisioning: It is recommended that the CSP provide the method of operating and
provisioning various types of accounts in accordance with CSC's characteristics based on the service
level such as one-time usage and permanent account, types of virtual desktop environments, and
allocating options for the virtual desktop environments.
NOTE 1 – User account provisioning depending on the CSC types is described in Appendix V.

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