1、 International Telecommunication Union ITU-T Y.3011TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2012) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Future networks Framework of network virtualization for future net
2、works Recommendation ITU-T Y.3011 ITU-T 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 p
3、rotocols 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 and applications Y.1100Y.1199 Architecture, access, network capabilities and resour
4、ce 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 Y.1800Y.1899 IPTV over NGN Y.1900Y.1999 NEXT GENERATION NETWORKS Frameworks and
5、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 networks in NGN Y.2250Y.2299 Numbering, naming and addressing Y.2300Y.2399 Network
6、 management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Smart ubiquitous networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 Future networks Y.3000Y.3099For further details, please refer to the list of IT
7、U-T Recommendations. Rec. ITU-T Y.3011 (01/2012) i Recommendation ITU-T Y.3011 Framework of network virtualization for future networks Summary Recommendation ITU-T Y.3011 describes the framework of network virtualization for future networks (FNs). It presents its motivation and definition, and descr
8、ibes the concept of logically isolated network partition (LINP) that is provisioned by network virtualization. This Recommendation also discusses the problem spaces of network virtualization and investigates its design goals. Finally, this Recommendation discusses the applicability of network virtua
9、lization by summarizing its advantages and disadvantages. An appendix provides detailed use cases on various aspects of network virtualization, such as experimental network and mobility. History Edition Recommendation Approval Study Group 1.0 ITU-T Y.3011 2012-01-13 13 ii Rec. ITU-T Y.3011 (01/2012)
10、 FOREWORD The 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 stu
11、dying technical, 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 gro
12、ups which, in 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
13、ISO and IEC. 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 provisi
14、ons (to ensure, 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 suc
15、h words does 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 positio
16、n concerning 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, protecte
17、d by patents, 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 2012 All rights reserved. No part of t
18、his publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T Y.3011 (01/2012) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 3.1 Term defined elsewhere . 1 3.2 Terms defined in this Recommendation . 1 4 Abbreviations and ac
19、ronyms 2 5 Conventions 2 6 Overview 2 7 Problem spaces . 4 7.1 Coexistence of multiple networks 4 7.2 Simplified access to resources 5 7.3 Flexibility in provisioning 5 7.4 Evolvability 6 8 Design goals . 6 8.1 Isolation 6 8.2 Network abstraction 6 8.3 Topology awareness and quick reconfigurability
20、. 7 8.4 Performance 7 8.5 Programmability . 7 8.6 Management . 8 8.7 Mobility 8 8.8 Wireless 9 9 Applicability . 9 10 Environmental considerations 9 11 Security considerations . 10 Appendix I Detailed description of LINP . 11 Appendix II Use cases of network virtualization 13 II.1 Case 1: Network vi
21、rtualization for network service providers . 13 II.2 Case 2: Experiments on the feasibility of new network architectures b-GENI GDD0608 14 II.3 Case 3: mobility in virtualized network . 14 II.4 Case 4: Wireless access network virtualization 16 Bibliography. 19 iv Rec. ITU-T Y.3011 (01/2012) Introduc
22、tion Future networks (FNs) are networks that will be able to provide revolutionary services, capabilities, and facilities that are difficult to support using existing network technologies. One of the basic objectives of FNs is service awareness. The number and range of services are expected to explo
23、de in the future, and FNs need to adapt to the surge in the number of services ITU-T Y.3001. That surge in the number of services makes it difficult to satisfy the requirements of every service on a single network architecture. However, it is unrealistic to realize heterogeneous network architecture
24、s using multiple physical networks because of the installation, operation, and maintenance costs. FNs therefore need to realize diverse services and heterogeneous network architectures on a common physical network. The future information and communication infrastructure is expected to support arbitr
25、ary kinds of social and economic activities. For example, while a proliferating number of network services are emerging and such services require high-speed, large-volume, low-latency network connectivity for voice, video, database communications, it is also imperative to ensure low-power consumptio
26、n. A mixture of contradicting goals, including those described above, is to be resolved by the flexibly reconfigurable networks that accommodate multiple virtual networks with different capabilities. It is therefore crucial to make the networks more flexible and more reconfigurable so that they cont
27、inuously and dynamically evolve to adapt to the changing requirements for future network services and applications. It is especially important to optimize the usage of the limited resources and maximize the number of users of the resources by quickly and dynamically adapting to environmental changes
28、, for example, the emergency situations caused by natural disasters, through tailoring the amount and the quality of resources allocated for each virtual network and switching between multiple virtual networks with different capabilities. At the same time, to make diverse services flourish, it is pr
29、eferable for networks to provide easy methods for experimenting and/or small-scale deployment. This has to be done without causing unexpected effects for others, so it is often done by building completely separate networks. If experimental networks and/or test-beds could be built on real networks th
30、at share common physical networks and could still provide isolated network environment, it will give developers, providers, and users of the emerging technologies an ideal environment to design, develop, and evaluate new services. Network virtualization is a technology that realizes isolated and fle
31、xible networks in order to support a broad range of network architectures, services, and users that do not interfere with others. It also enables the easy establishment of experimental networks and accelerates research and development on future network technologies. Therefore, network virtualization
32、 is considered as a key technology for realizing FNs. This Recommendation provides the framework of network virtualization technology. Rec. ITU-T Y.3011 (01/2012) 1 Recommendation ITU-T Y.3011 Framework of network virtualization for future networks 1 Scope This Recommendation defines network virtual
33、ization and provides an overview of, and motivation for, network virtualization. It also describes problem spaces, design goals, and applicability of network virtualization. Use cases for network virtualization are discussed in an appendix. 2 References The following ITU-T Recommendations and other
34、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 Recommendation are therefore encouraged to
35、 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 not give it, as a stand-alone document, t
36、he status of a Recommendation. ITU-T Y.3001 Recommendation ITU-T Y.3001 (2011), Future networks: Objectives and design goals. 3 Definitions 3.1 Term defined elsewhere This Recommendation uses the following term defined elsewhere: 3.1.1 future network (FN) ITU-T Y.3001: A network able to provide serv
37、ices, capabilities, and facilities difficult to provide using existing network technologies. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 logical resource: An independently manageable partition of a physical resource, which inherits the same charact
38、eristics as the physical resource and whose capability is bound to the capability of the physical resource. NOTE “independently“ means mutual exclusiveness among multiple partitions at the same level. 3.2.2 logically isolated network partition (LINP): A network that is composed of multiple virtual r
39、esources which is isolated from other LINPs. NOTE “logically isolated“, which is the counter concept of “physically isolated“, means mutual exclusiveness of the subjects (i.e., network partition, in this case), while the original subjects may be physically united/shared within the common physical co
40、nstraints. 3.2.3 virtual resource: An abstraction of physical or logical resource, which may have different characteristics from the physical or logical resource and whose capability may be not bound to the capability of the physical or logical resource. NOTE “different characteristics“ means simpli
41、fication or extension of the resource characteristics. “different characteristics“ allows the virtual resource to expose access or control methods different from the original physical or logical resource. 2 Rec. ITU-T Y.3011 (01/2012) 3.2.4 network virtualization: A technology that enables the creat
42、ion of logically isolated network partitions over shared physical networks so that heterogeneous collections 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. NOTE Re
43、fer to the note of the definition of LINP for “logically isolated“. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: FN Future Network IPsec Internet Protocol security LINP Logically Isolated Network Partition MNO Mobile Network Operator MVNO Mobile Vir
44、tual Network Operator PNM Physical Network Manager VLAN Virtual Local Area Network VPN Virtual Private Network VRM Virtual Resources Manager 5 Conventions None. 6 Overview Network virtualization is a method that allows multiple virtual networks, called logically isolated network partitions (LINPs),
45、to coexist in a single physical network. In order to provide LINPs, physical resources are partitioned and abstracted as virtual resources and the virtual resources are interconnected to create an LINP b-Chowdhuryb-GENI GDD0608b-Nakao. These virtual resources can be created on physical resources suc
46、h as routers, switches and hosts. As such, virtual resources are either allocated to each LINP or else multiple virtual resources are aggregated into a single virtual resource. LINPs are isolated from each other, and when combined with programmability in virtual resources, users of LINPs can program
47、 the virtual resources on the virtualization layer. In other words, each LINP can provide the corresponding users with services similar to those provided by traditional networks without network virtualization. The users of LINPs are not limited to the users of services or applications, but can inclu
48、de service providers. For example, a service provider can lease an LINP and can provide emerging services or technologies such as the cloud computing service. The service providers can realize the emerging services as if they own a dedicated physical network. In order to facilitate the deployment of
49、 network virtualization, it is necessary to provide control and management procedures such as creating, monitoring, and measuring the status of LINPs. Figure 1 represents the conceptual architecture of network virtualization, which consists of LINPs over physical resources supporting network virtualization. A single physical resource can be shared among multiple virtual resources and each LINP consists of multiple virtual resources. Each LINP is managed by an individual LINP manager. In the figure, the physical res
