1、 International Telecommunication Union ITU-T Y.3503TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (05/2014) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Cloud Computing Requirements for desktop as a service Recommendation ITU-T Y.3503 ITU-T Y-S
2、ERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.200Y.299 Network aspects Y.300Y.399 Interfaces and protocols Y.400Y.499 Numbering, addressing a
3、nd naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 Architecture, access, network capabilities and resource management Y.1200Y.1299 Transport Y.1300
4、Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 IPTV over NGN Y.1900Y.1999 NEXT GENERATION NETWORKS Frameworks and functional architecture models Y.2000Y.2099
5、 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Enhancements to NGN Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures a
6、nd protocols Y.2500Y.2599 Packet-based Networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 FUTURE NETWORKS Y.3000Y.3499 CLOUD COMPUTING Y.3500Y.3999For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T
7、 Y.3503 (05/2014) i Recommendation ITU-T Y.3503 Requirements for desktop as a service Summary As one of cloud computing service categories, desktop as a service (DaaS) provides cloud service customers with desktop functions remotely delivered by cloud service providers. Recommendation ITU-T Y.3503 i
8、ntroduces the concept of DaaS, and describes general and functional requirements. To derive those requirements relevant use cases are also presented. History Edition Recommendation Approval Study Group Unique ID*1.0 ITU-T Y.3503 2014-05-22 13 11.1002/1000/12167 Keywords Desktop as a service, DaaS, v
9、irtual desktop, virtual desktop infrastructure. _ *To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T Y.3503 (05/2014) FOREWORD Th
10、e International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying techni
11、cal, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, i
12、n turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
13、 NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensu
14、re, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does
15、 not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning
16、 the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents
17、, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2014 All rights reserved. No part of this publicat
18、ion may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T Y.3503 (05/2014) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 1 4 Abbreviations and acronyms 2 5 Co
19、nvention 3 6 Introduction to desktop as a service (DaaS) . 3 6.1 Main advantages of DaaS . 5 6.2 General configuration for DaaS 5 6.3 Interaction between DaaS components 7 7 DaaS general requirements . 7 8 DaaS functional requirements 8 8.1 Operation and management requirements 8 8.2 DaaS platform-s
20、ide functional requirements 9 8.3 DaaS client-side functional requirements . 10 8.4 DaaS platform-DaaS client interaction functional requirements 11 8.5 DaaS security requirements 11 9 Security considerations . 12 Appendix I Relationship between DaaS logical components and the cloud computing refere
21、nce architecture 13 Appendix II DaaS client classification 14 Appendix III DaaS use cases 15 Appendix IV Value for response time limit 22 Appendix V Service provisioning based on CSC types in DaaS 23 V.1 Types of cloud service customer 23 V.2 User account provisioning based on CSC types in DaaS . 23
22、 V.3 Service provisioning in DaaS . 24 Bibliography. 25 Rec. ITU-T Y.3503 (05/2014) 1 Recommendation ITU-T Y.3503 Requirements for desktop as a service 1 Scope This Recommendation provides use cases, general requirements and functional requirements for desktop as a service (DaaS). 2 References The f
23、ollowing ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this R
24、ecommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does
25、not give it, as a stand-alone document, the status of a Recommendation. ITU-T X.1601 Recommendation ITU-T X.1601 (2014), Security framework for cloud computing. ITU-T Y.3501 Recommendation ITU-T Y.3501 (2013), Cloud computing framework and high-level requirements. ITU-T Y.3510 Recommendation ITU-T Y
26、.3510 (2013), Cloud computing infrastructure requirements. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 cloud service customer ITU-T Y.3501: A person or organization that consumes delivered cloud services within a contract with a clo
27、ud service provider. 3.1.2 cloud service provider ITU-T Y.3501: An organization that provides and maintains delivered cloud services. 3.1.3 hypervisor ITU-T Y.3510: A type of system software that allows multiple operating systems to share a single hardware host. 3.1.4 virtual machine b-DMTF OVF: The
28、 complete environment that supports the execution of guest software. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 DaaS client: A physical device and associated software running on the device that collectively enables a cloud service user to access d
29、esktop as a service (DaaS). 3.2.2 desktop as a service (DaaS): A cloud service category in which the capabilities provided to the cloud service customer are the ability to build, configure, manage, store, execute and deliver users desktop functions remotely. 3.2.3 virtual desktop: An environment for
30、 accessing end users desktop functions remotely. 2 Rec. ITU-T Y.3503 (05/2014) NOTE Examples of end users desktop functions can include desktop interface functions for applications, data access functions for multimedia data, and control functions for input/output (I/O) devices. 3.2.4 virtual desktop
31、 infrastructure (VDI): A desktop as a service (DaaS) solution enabling the hosting of a desktop operating system within a virtual machine. NOTE In this Recommendation, VDI means that the virtual machine hosting the desktop operation system is running in a cloud computing environment. 3.2.5 virtual d
32、esktop template: A representation of a set of system configuration and application parameters with an option of including customer personalization, and other desired attributes. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: 3D Three Dimensional 3G Th
33、ird Generation CPU Central Processing Unit CSC Cloud Service Customer CSP Cloud Service Provider CRM Customer Relationship Management DaaS Desktop as a Service DCN Data Communication Network DHCP Dynamic Host Configuration Protocol DNS Domain Name System DTLS Datagram Transport Layer Security ERP En
34、terprise Resource Planning FEC Forward Error Correction GPS Global Positioning System HD High Definition HTML Hypertext Markup Language HTTP Hypertext Transfer Protocol IaaS Infrastructure as a Service I/O Input/Output IT Information Technology LAN Local Area Network OS Operating System PLMN Public
35、Land Mobile Network PSTN Public Switched Telephone Network QoE Quality of Experience RAM Random Access Memory SLA Service Level Agreement Rec. ITU-T Y.3503 (05/2014) 3 SSL Secure Socket Layer TCP Transmission Control Protocol UDP User Datagram Protocol VDI Virtual Desktop Infrastructure VM Virtual M
36、achine VPN Virtual Private Network 5 Convention The keywords “is required to“ indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. The keywords “is recommended“ indicate a requirement which is recommen
37、ded but which is not absolutely required. Thus this requirement need not be present to claim conformance. The keywords “can optionally“ indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendors implemen
38、tation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. In the body of this Recommendation and its annexes, the words shall, s
39、hall not, should, and may sometimes appear, in which case they are to be interpreted, respectively, as is required to, is prohibited from, is recommended, and can optionally. The appearance of such phrases or keywords in an appendix or in material explicitly marked as informative are to be interpret
40、ed as having no normative intent. 6 Introduction to desktop as a service (DaaS) DaaS is defined as a cloud service category in which the capabilities provided to the cloud service customer (CSC) are the ability to build, configure, manage, store, execute and deliver users desktop functions remotely.
41、 With DaaS, the user experience is achieved through a user interface, which is presented on a DaaS client over the network. Figure 6-1 shows the conceptual view of DaaS. 4 Rec. ITU-T Y.3503 (05/2014) Figure 6-1 Conceptual view of DaaS Instead of maintaining and running a desktop operating system and
42、 applications on CSC devices, servers of a cloud service provider (CSP) located in the cloud are used to execute the instances of users virtual desktops. This allows a party (e.g., an organization) to run end users operating systems and applications, and keep their data in the cloud computing enviro
43、nment. Based on application streaming and virtualization technologies, CSCs can access the virtual desktop environment through cloud infrastructure. A few technologies can be used for providing services of the DaaS like virtual desktop infrastructure (VDI) and web-based solutions with various delive
44、ry protocols such as the virtual desktop delivery protocol and the web-based delivery protocol shown in Figure 6-2. .Y.3503(14)_F6-2Access layerServices layerResource layerVirtual desktopdelivery protocolUser layerWeb-baseddelivery protocolDaaS client DaaS clientFigure 6-2 DaaS delivery solutions VD
45、I supports the users virtual desktop and recreates it in an environment hosted on a remote system. A virtual desktop is executed for each user from the server side. Users access this Rec. ITU-T Y.3503 (05/2014) 5 environment remotely through DaaS clients, with all virtual desktop associated processi
46、ng. A virtual desktop delivery protocol is used to deliver the virtual desktop. In the web-based DaaS solution, a web-based server invokes application services from different servers and aggregates them to build a virtual desktop service. The web-based DaaS solution relies on cloud services provided
47、 through the use of web oriented technologies, i.e., based on the hypertext transfer protocol (HTTP), hypertext markup language (HTML) and the new features supported by HTML5 b-W3C-HTML5. 6.1 Main advantages of DaaS The main advantages of DaaS b-ITU-T FGCC1 are: Enhanced management and security: Sin
48、ce all desktop applications actually run in a CSP server, they are more secure than if they were installed on each users DaaS client since the CSP can focus more on security aspects. Lower total cost of ownership: By placing emphasis on the data centre rather than on individual user devices, DaaS pr
49、omotes longer hardware life. Organizations or enterprises seeking to avoid additional costs can switch part of their information and communication technology infrastructure from capital expenditure to operating expenditure, as they now pay for virtual desktops. Also, decoupling the desktop operating system from the hardware permits the use of cost-effective users devices. Preservation of user experience: DaaS allows for a rich user experience by enabling the possible ch
