1、 International Telecommunication Union ITU-T Y.3300TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (06/2014) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Future networks Framework of software-defined networking Recommendation ITU-T Y.3300 ITU-T
2、Y-SERIES 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, addressin
3、g and 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.1
4、300Y.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.2
5、099 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 architecture
6、s and 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.3499CLOUD COMPUTING Y.3500Y.3999 For further details, please refer to the list of ITU-T Recommendations. Rec. IT
7、U-T Y.3300 (06/2014) i Recommendation ITU-T Y.3300 Framework of software-defined networking Summary Recommendation ITU-T Y.3300 describes the framework of software-defined networking (SDN) to specify fundamentals of SDN. The definitions, objectives, high-level capabilities, requirements and high-lev
8、el architecture of SDN are addressed in this Recommendation. Appendix I describes areas for further consideration in SDN standardization. History Edition Recommendation Approval Study Group Unique ID*1.0 ITU-T Y.3300 2014-06-06 13 11.1002/1000/12168 Keywords SDN, software-defined networking. _ *To a
9、ccess 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.3300 (06/2014) FOREWORD The International Telecommunication Union (ITU) is the Un
10、ited 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 technical, operating and tariff questions and issuing Recomme
11、ndations 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, in turn, produce Recommendations on these topics. The ap
12、proval 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. NOTE In this Recommendation, the expression “Administr
13、ation“ 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 ensure, e.g., interoperability or applicability) and compli
14、ance 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 not suggest that compliance with the Recommendation is
15、 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 the evidence, validity or applicability of claimed Int
16、ellectual 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, which may be required to implement this Recommendatio
17、n. 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 publication may be reproduced, by any means whatsoever, without
18、 the prior written permission of ITU. Rec. ITU-T Y.3300 (06/2014) 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 Conventions 2 6 Introduction 2 7 Overview 3 8 Objectives
19、. 3 9 High-level capabilities 4 10 Requirements 5 11 High-level architecture . 5 11.1 Application layer 5 11.2 SDN control layer . 6 11.3 Resource layer 6 11.4 Multi-layer management functions . 7 11.5 Interfaces 7 12 Environmental considerations 8 13 Security considerations . 8 Appendix I Areas for
20、 further considerations in SDN standardization 9 I.1 Interworking . 9 I.2 Verification of SDN applications . 9 I.3 Adaptation to large-scale networks 10 I.4 Design of resource abstraction . 10 I.5 Virtualization of network elements 10 I.6 Multiple-level of programmability . 11 I.7 Programmatic exten
21、sion in resource layer . 11 Bibliography. 13 Rec. ITU-T Y.3300 (06/2014) 1 Recommendation ITU-T Y.3300 Framework of software-defined networking 1 Scope This Recommendation describes the framework of software-defined networking (SDN) by providing: definitions, objectives, high-level capabilities, req
22、uirements, and high-level architecture of the fundamentals of SDN. In addition, Appendix I describes areas for further consideration in SDN standardization. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute prov
23、isions 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 Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendati
24、ons 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 not give it, as a stand-alone document, the status of a Recommendation. ITU-T Y.3001 Recommendation ITU-T Y.3001 (2011), Futu
25、re Networks: Objectives and Design Goals. ITU-T Y.3011 Recommendation ITU-T Y.3011 (2012), Framework of network virtualization for Future Networks. ITU-T M.3400 Recommendation ITU-T M.3400 (2000), TMN management functions. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the follow
26、ing term defined elsewhere: 3.1.1 network virtualization ITU-T Y.3011: A technology that enables the creation of logically isolated network partitions over shared physical networks so that heterogeneous collection of multiple virtual networks can simultaneously coexist over the shared networks. This
27、 includes the aggregation of multiple resources in a provider and appearing as a single resource. 3.2 Terms defined in this Recommendation This Recommendation defines the following term: 3.2.1 software-defined networking: A set of techniques that enables to directly program, orchestrate, control and
28、 manage network resources, which facilitates the design, delivery and operation of network services in a dynamic and scalable manner. 2 Rec. ITU-T Y.3300 (06/2014) 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: AAA Authentication, Authorization, and A
29、ccounting FCAPS Fault, Configuration, Accounting, Performance, and Security OSI Open System Interconnection SDN Software-Defined Networking 5 Conventions This Recommendation uses the following conventions: The term “is required to“ indicates a requirement which must be strictly followed, and from wh
30、ich no deviation is permitted, if conformance to this Recommendation is to be claimed. The term “is recommended“ indicates a requirement which is recommended, but which is not absolutely required. Thus, this requirement need not be present to claim conformance. 6 Introduction Due to the great succes
31、s of communication technologies, diverse applications are realized on networks, and the requirements that they bring are diverging. To support these diverging requirements, it is necessary to make networks even more controllable and manageable. The necessity to treat different traffic in different m
32、anners, and to make networks more application- and service-oriented is also increasing. Technologies that enable more direct and lower-level (e.g., flow-level) control methods of data packet forwarding are emerging. These technologies can simplify the reaction of network resources (e.g., switches or
33、 routers) to operations, and significantly increase the controllability of networks for operators. With modeling and programing of network resources, networks can be controlled in an automated manner, which enables more agile operations of the networks. This change of control method can also provide
34、 a chance to redesign control functionalities by introducing logically centralized and programmable control of network resources through standardized interfaces and protocols. This approach allows for: logically centralized network control, which decreases the number of points to control and manage;
35、 supporting network virtualization as one important feature of the network architecture; defining, controlling and managing network resources using software; thus, allowing network services to be provided in a deterministic manner in accordance with the requested behaviour; and network customization
36、, which is necessary for efficient and effective network deployment and operations. In order to realize the aforementioned features, this Recommendation provides the framework of software-defined networking (SDN) by specifying the fundamentals of SDN with its definitions, objectives, high-level capa
37、bilities, requirements and high-level architecture. While there have been various efforts to develop SDN-related technologies and standards (see ITU-T Y.3001, ITU-T Y.3011, b-ITU-T Y.2622, b-ETSI NFV, b-IETF I2RS b-IETF RFC 3746, b-ONF and b-OpenDayLight) with different approaches and different Rec.
38、 ITU-T Y.3300 (06/2014) 3 focuses, they all share the same objective of providing the programmability of network resources as described above, which is a core technology for the networks of the future. 7 Overview SDN is a set of techniques that enables users to directly program, orchestrate, control
39、 and manage network resources, which facilitates the design, delivery and operation of network services in a dynamic and scalable manner. Figure 7-1 depicts the basic concept of SDN. Figure 7-1 Concept of SDN SDN relocates the control of network resources to a dedicated network element, namely SDN c
40、ontroller, which provides a means to program, orchestrate, control and manage the network resources through software (i.e., SDN applications). The distributed network resources perform the network functions such as data packet transport and processing, but the behaviors of network resources are dire
41、ctly controlled via a standardized interface (i.e., resource-control interface) and the relevant information and data models. See b-IETF RFC 3444. The SDN controller uses the interface and arbitrates the control of network resources in a logically centralized manner. The SDN controller manages and c
42、onfigures the distributed network resources and provides an abstracted view of the network resources to the SDN applications via another standardized interface (i.e., application-control interface) and the relevant information and data models. The SDN application can customize and automate the opera
43、tions (including management) of the abstracted network resources in a programmable manner via this interface. Note that the SDN controller can provide different types of interfaces to SDN applications (e.g., more abstracted and more object-oriented). 8 Objectives The objectives of SDN are to realize
44、: Faster network business cycles SDN reduces the response time of business requests to network providers, e.g., to increase customer satisfaction or to shorten the payback time of investment through further automation of network operations; 4 Rec. ITU-T Y.3300 (06/2014) Acceleration of innovation SD
45、N accelerates business and/or technical innovation through more flexibility of the network operations, thus making trials easier; Accelerated adaptation to customer demands SDN facilitates the accommodation of customers connectivity requirements by means of dynamic negotiation of network service cha
46、racteristics and of dynamic network resource control; Improved resource availability and usage efficiency SDN is meant to improve network resource availability and efficiency, in particular when combined with network virtualization, due to the introduction of a high level of automation in the overal
47、l service delivery and operation procedures, from service parameter negotiation to fulfilment and assurance; Customization of network resources including service-aware networking SDN allows network customization for the network services which have different requirements, through the programming of n
48、etwork resource operations, including the dynamic enforcement of a set of policies (e.g., resource planning as a function of the number of customers orders to be processed over time, forwarding and routing, quality of service (QoS) and traffic engineering, security). 9 High-level capabilities SDN pr
49、ovides the following high-level capabilities: Programmability The behaviour of network resources can be customized by SDN applications through a standardized programming interface for network control and management functionality. The user of the interface may be network providers, service providers, and customers including end-users. This enables the SDN applications to automate the operations of network resources according to their needs. Resource abstractio
