1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T Y.3301 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (09/2016) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES Future networks Funct
2、ional requirements of software-defined networking Recommendation ITU-T Y.3301 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, a
3、pplications and middleware Y.200Y.299 Network aspects Y.300Y.399 Interfaces and protocols Y.400Y.499 Numbering, addressing 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 an
4、d applications Y.1100Y.1199 Architecture, access, network capabilities and resource management Y.1200Y.1299 Transport Y.1300Y.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
5、 Y.1800Y.1899 IPTV over NGN Y.1900Y.1999 NEXT GENERATION NETWORKS Frameworks and functional architecture models Y.2000Y.2099 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and n
6、etworks in NGN Y.2250Y.2299 Enhancements to NGN Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures 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
7、 Y.3000Y.3499 CLOUD COMPUTING Y.3500Y.3999 INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES General Y.4000Y.4049 Definitions and terminologies Y.4050Y.4099 Requirements and use cases Y.4100Y.4249 Infrastructure, connectivity and networks Y.4250Y.4399 Frameworks, architectures and protocols Y.4400
8、Y.4549 Services, applications, computation and data processing Y.4550Y.4699 Management, control and performance Y.4700Y.4799 Identification and security Y.4800Y.4899 Evaluation and assessment Y.4900Y.4999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.3301 (09/2
9、016) i Recommendation ITU-T Y.3301 Functional requirements of software-defined networking Summary Recommendation ITU-T Y.3301 describes the functional requirements of software-defined networking (SDN) including the general requirements and functional requirements of the SDN application layer, SDN co
10、ntrol layer, SDN resource layer and any multilayer management functions. This Recommendation is based on Recommendation ITU-T Y.3300 (Framework of software-defined networking), which describes the fundamentals of SDN including the definitions, objectives, high-level capabilities, requirements and hi
11、gh-level architecture of SDN. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T Y.3301 2016-09-29 13 11.1002/1000/13016 Keywords Abstraction, multilayer management, orchestration, programmability, SDN. * To access the Recommendation, type the URL http:/handle.itu.int/ in the a
12、ddress 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.3301 (09/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, i
13、nformation 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 Recommendations on them with a view to standardizing telecommunications on a
14、 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 approval of ITU-T Recommendations is covered by the procedure laid down
15、 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 “Administration“ is used for conciseness to indicate both a telecommunication a
16、dministration 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 compliance with the Recommendation is achieved when all of these mandatory
17、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 required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attenti
18、on 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 Intellectual Property Rights, whether asserted by ITU members or others o
19、utside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the lat
20、est information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2016 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T Y.3301 (09/2016) iii Tabl
21、e 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 . 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Overview . 2 7 Functional requirements . 2 7.1 General requirements 2 7.2 SDN application layer 3 7.3 SDN contro
22、l layer . 3 7.4 SDN resource layer . 4 7.5 Multilayer management functions 4 8 Environmental considerations 5 9 Security considerations . 5 Rec. ITU-T Y.3301 (09/2016) 1 Recommendation ITU-T Y.3301 Functional requirements of software-defined networking 1 Scope This Recommendation describes the funct
23、ional requirements of software-defined networking (SDN), which are defined in ITU-T Y.3300, by providing: general requirements, functional requirements of the SDN application layer, functional requirements of the SDN control layer, functional requirements of the SDN resource layer, and functional re
24、quirements of the multilayer management functions. NOTE In ITU-T Y.3300 the term “application layer“ refers to “SDN application layer“ and “resource layer“ refers to “SDN resource layer“ As the names “application layer“ and “resource layer“ are too general this Recommendation uses more specific name
25、s of layers such as “SDN application layer“ and “SDN resource layer“. 2 References The following 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
26、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 Recommendations and other references listed below. A list of the currently valid ITU-T Recommendati
27、ons 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.3011 Recommendation ITU-T Y.3011 (2012), Framework of network virtualization for future networks. ITU-T Y.3300 Recommendation ITU-T
28、Y.3300 (2014), Framework of software-defined networking. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 software-defined networking ITU-T Y.3300: A set of techniques that enables to directly program, orchestrate, control and manage net
29、work resources, which facilitates the design, delivery and operation of network services in a dynamic and scalable manner. 3.1.2 network virtualization ITU-T Y.3011: A technology that enables the creation of logically isolated network partitions over shared physical networks so that heterogeneous co
30、llection of multiple virtual networks can simultaneously coexist over the shared networks. This includes the aggregation of multiple resources in a provider and appearing as a single resource. 3.1.3 virtual resource ITU-T Y.3011: An abstraction of physical or logical resource, which may have differe
31、nt characteristics from the physical or logical resource and whose capability may be not bound to the capability of the physical or logical resource. 2 Rec. ITU-T Y.3301 (09/2016) 3.2 Terms defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation uses the following abbre
32、viations and acronyms: BSS Business Support Systems FCAPS Fault, Configuration, Accounting, Performance and Security IP Internet Protocol MAC Media Access Control OSS Operations Support Systems SDN Software-Defined Networking 5 Conventions This Recommendation uses the following conventions: The term
33、 “is required to“ indicates a requirement which must be strictly followed and from which 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 requirem
34、ent need not be present to claim conformance. 6 Overview ITU-T Y.3300, the framework of SDN, defines SDN as a set of techniques that enables network resources to be directly programmed, orchestrated, controlled and managed, which facilitates the design, delivery and operation of network services in
35、a dynamic and scalable manner. The high-level architecture of SDN in the framework consists of the application layer, SDN control layer, resource layer and multilayer management functions. The application layer executes SDN applications and enables network resources to act as instructed from SDN app
36、lications in a programmatic manner via the SDN control layer. The SDN control layer provides a means to control the behaviours of network resources via resource-control interfaces. The resource layer performs the transporting and the processing of data packets based on the decisions of the SDN contr
37、ol layer. The multilayer management functions provide functionalities for managing other layers including FCAPS. This Recommendation defines the following functional requirements of SDN: general requirements; SDN application layer; SDN control layer; SDN resource layer; and multilayer management fun
38、ctions. 7 Functional requirements 7.1 General requirements The general requirements are as follows: It is required to provide interoperability with external OSS/BSS. Rec. ITU-T Y.3301 (09/2016) 3 It is required to provide an orchestration functionality of the SDN application layer and SDN control la
39、yer, and multilayer management to handle the lifecycle management of software-based SDN functions. It is required to provide scalability for supporting a large number of users and vast geographical areas. It is required to provide a management support functionality in each layer to enable the delega
40、tion of multilayer management functions. It is recommended to maximize the energy-efficient usage of physical resources of all layers. 7.2 SDN application layer The SDN application layer executes SDN applications and enables network resources to behave in a service-aware, programmatic manner. The fu
41、nctional requirements for the SDN application layer are as follows: It is required to create and apply the application-specific programs to the SDN resource layer by interacting with the SDN control layer. It is required to support multiple applications at the same time. It is required to notify net
42、work events from the SDN control layer to the corresponding SDN application. NOTE Network events are information of network resources that are necessary for SDN applications to run in an appropriate manner, e.g., start/end of an activity, failure, performance degradation to be handled by SDN applica
43、tions. It is required to orchestrate multiple SDN applications within the SDN application layer. It is required to categorize SDN applications and combine multiple applications into an integrated SDN application. 7.3 SDN control layer The SDN control layer includes application support, orchestration
44、, and abstraction functions. Orchestration provides the coordination of requests from the SDN application layer and automated control of network resources, such as the management of physical and virtual network topologies, network resources and traffic. Abstraction provides abstracted views of the p
45、roperty and behaviour of underlying network resources, in order to support the management and orchestration of physical and virtual network resources. The functional requirements for the SDN control layer are as follows: It is required to provide orchestration, abstraction and programmability of the
46、 network resources. NOTE Programmability provides the ability to control or configure the network resources by introducing a high level of automation. Behaviour of network resources can be programmed by SDN applications for network control and management functionality. It is required to discover und
47、erlying network topology to see how network resources (e.g., SDN-enabled switches) connect to each other. It is required to collect and maintain network information about the capability of network resources and network-wide information, including the status of forwarding tables, routing policies and
48、 network topologies. It is required to back up network information in case of failures. 4 Rec. ITU-T Y.3301 (09/2016) It is required to build and update forwarding paths constituted by network resources, such as switches, routers and data processing entities. It is required to provide an abstracted
49、view of different network solutions (e.g., Packet Transport Network, Optical Transport Network) to SDN applications. It is required to expose network configurations (e.g., routing policies) to the SDN application layer. It is required to maintain a set of lists of data processing entities (e.g., firewall, transcoding) categorized by their capabilities. It is recommended to create and maintain mapping information between SDN applications and network resources.
