1、 International Telecommunication Union ITU-T Y.2081TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (07/2012) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Frameworks and functional architecture models Distributed service
2、networking traffic optimization control functions Recommendation ITU-T Y.2081 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
3、 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 and applications Y.1100Y.1199 Architect
4、ure, 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 Y.1800Y.1899 IPTV over NGN Y.1900Y.1
5、999 NEXT GENERATION NETWORKS Frameworks and functional architecture models Y.2000Y.2099Quality 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,
6、 naming and addressing 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 Y.3000Y.3499 CLOUD COMPU
7、TING Y.3500Y.3999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.2081 (07/2012) i Recommendation ITU-T Y.2081 Distributed service networking traffic optimization control functions Summary Recommendation ITU-T Y.2081 specifies the functional architecture for traf
8、fic optimization control functions (TOCFs), in support of steering traffic distribution according to certain optimization objectives in the environment of DSN described in Recommendation ITU-T Y.2080. The main objective of this Recommendation is to specify the functional entities of the TOCF and ref
9、erence points, including information flows, between these functional entities. History Edition Recommendation Approval Study Group 1.0 ITU-T Y.2081 2012-07-29 13 Keywords Distributed service networking, DSN, functional architecture, functional entities, functions, reference points, traffic optimizat
10、ion control function, TOCF. ii Rec. ITU-T Y.2081 (07/2012) 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)
11、 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 worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four year
12、s, 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 in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the neces
13、sary 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 administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However
14、, 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 provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative eq
15、uivalents 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 RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a
16、 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 outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU
17、had not 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 latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.
18、int/ITU-T/ipr/. ITU 2012 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.2081 (07/2012) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms
19、defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Overview of TOCFs . 3 7 TOCF functional architecture . 4 7.1 Architecture framework 4 7.2 Functional entities 6 8 Reference points and information flows . 7 8.1 Reference point T1 between STIC-FE and OPP-FE 7 8.2 Ref
20、erence point T2 between DTIC-FE and OPP-FE . 9 8.3 Reference point T3 between OPS-FE and OPP-FE . 12 8.4 Reference point A4 between AF and OPP-FE . 12 8.5 Reference point C5 between RLF and OPP-FE . 16 9 Security considerations . 20 Rec. ITU-T Y.2081 (07/2012) 1 Recommendation ITU-T Y.2081 Distribut
21、ed service networking traffic optimization control functions 1 Scope This Recommendation specifies the traffic optimization control functions (TOCFs) and reference points between TOCF functional entities in support of steering traffic distribution according to certain optimization objectives in the
22、environment of distributed service networking (DSN) and next generation networks (NGN). The TOCF supports application traffic optimization based on network awareness features (including topology information and traffic information) and provides capabilities for service providers (SPs) and network pr
23、oviders to work jointly to optimize the transfer of service traffic. 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 v
24、alid. 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 Recommendatio
25、ns 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.2012 Recommendation ITU-T Y.2012 (2010), Functional requirements and architecture of next generation networks. ITU-T Y.2080 Recommend
26、ation ITU-T Y.2080 (2012), Functional architecture for distributed service networking. ITU-T Y.2206 Recommendation ITU-T Y.2206 (2010), Requirements for distributed service networking capabilities. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhe
27、re: 3.1.1 content node ITU-T Y.2080: A distributed service networking (DSN) node which can be used for media content distribution, storage and/or caching. 3.1.2 distributed service networking ITU-T Y.2206: An overlay networking which provides distributed and manageable capabilities to support variou
28、s multimedia services and applications. 3.1.3 DSN node ITU-T Y.2206: A node used in DSN providing distributed functionalities, including distributed routing and distributed storage. 3.1.4 functional entity ITU-T Y.2012: An entity that comprises an indivisible set of specific functions. Functional en
29、tities are logical concepts, while groupings of functional entities are used to describe practical, physical implementations. 3.1.5 reference point ITU-T Y.2012: A conceptual point at the conjunction of two non-overlapping functional entities that can be used to identify the type of information pass
30、ing between these functional entities. 2 Rec. ITU-T Y.2081 (07/2012) 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 management and optimization policies: The policies used in the traffic optimization control function (TOCF) for improving the resource
31、management efficiency or optimizing the traffic transportation. These policies can be defined according to demands of the network provider, application provider, and also can be adjusted based on static and dynamic network information. 3.2.2 point of presence (POP): A point representing one or sever
32、al distributed service networking (DSN) nodes, which support DSN users to access services directly without having intermediate DSN nodes. 3.2.3 traffic optimization control function (TOCF): A function which optimizes application traffic distribution by the cooperation between network providers and a
33、pplication providers. The TOCF supports traffic optimization based on network awareness features (including topology information and traffic information). 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: ADSL Asymmetric Digital Subscriber Line AF Applic
34、ation Function AS Autonomous System CDF Content Delivery Function CSAF Content Service Application Function DSN Distributed Service Networking DTIC-FE Dynamic Traffic Information Collection Functional Entity HTTP Hypertext Transfer Protocol ID Identifier NEF Node Enrolment Function NGN Next Generati
35、on Network OPP-FE Optimization Policy Processing Functional Entity OPS-FE Optimization Policy Specification Functional Entity P2P Peer to Peer PID Partition ID POP Point Of Presence QoS Quality of Service RF Relay Function RLF Resource Location Function STIC-FE Static Topology Information Collection
36、 Functional Entity TOCF Traffic Optimization Control Function 5 Conventions None. Rec. ITU-T Y.2081 (07/2012) 3 6 Overview of TOCFs Traffic optimization control functions (TOCFs) make the delivery of application traffic, especially content application traffic and real-time application traffic (such
37、as P2P traffic and multimedia telephony traffic) more efficient and cost-effective. TOCFs also achieve efficient transportation, which improves service quality of the DSN network. TOCFs retrieve network information such as topology-related information, traffic-related information from underlying tra
38、nsport network(s) and traffic optimization policy(ies) from the network operator, which help to realize traffic optimization in applications running on top of these underlying networks. TOCFs support the following aspects: a) They provide suitable topology related information for the DSN node locate
39、d within their network. This information can be coarser or finer depending on the different traffic localization requirements. It mainly includes domains (e.g., AS domain) that the DSN nodes belong to, the IP address of those DSN nodes and the relative topological distance based on route hops or tra
40、versed number of AS domains. b) They provide suitable traffic-related information for the DSN node selection. This information can be provided in long-time or in real-time formats to reflect the traffic congestion situation. It mainly includes dynamic loads in links or paths between DSN nodes or POP
41、s. c) They provide information about optimal routing of voice, multimedia telephony and other real-time services. d) They provide the geographic information and property information (e.g., ADSL, cable or other access type) of DSN nodes to help the RLF make decisions regarding which content node is a
42、 better one to cache new content or to respond to a new content request. e) They hide the networks topology from applications. TOCFs support controlling traffic distribution according to certain optimization objectives in the environment of DSN. Figure 6-1 shows the relationship between the TOCF and
43、 other DSN functions as defined in ITU-T Y.2080. 4 Rec. ITU-T Y.2081 (07/2012) Figure 6-1 The position of the TOCF in the DSN architecture 7 TOCF functional architecture 7.1 Architecture framework TOCFs include four functional entities which support more efficient and cost-effective delivery of appl
44、ication traffic. In DSN architecture, TOCFs define traffic optimization policies for the AF and RLF. According to the policies, TOCFs transfer the required traffic optimization information to the AF and RLF. Figure 7-1 describes the TOCF functional architecture with functional entities and relevant
45、reference points. Rec. ITU-T Y.2081 (07/2012) 5 Figure 7-1 TOCF functional architecture The TOCF functional architecture includes the following functional entities: optimization policy specification functional entity (OPS-FE), whose main role is to define traffic optimization policies according to t
46、he demands of the network provider and/or application provider; optimization policy processing functional entity (OPP-FE), whose main role is to provide the required traffic optimization information to the AF and RLF according to the traffic optimization policies; static topology information collect
47、ion functional entity (STIC-FE), whose main role is to get the static topology information; dynamic traffic information collection functional entity (DTIC-FE), whose main role is to get the dynamic traffic information. Clause 7.2 provides a detailed description of the TOCF functional entities while
48、clause 8 describes the reference points related to the TOCF. 6 Rec. ITU-T Y.2081 (07/2012) 7.2 Functional entities 7.2.1 Optimization policy specification functional entity (OPS-FE) OPS-FE defines specific traffic optimization policy which is executed according to the demands of the network provider
49、 and/or application provider. OPS-FE performs the following function: It generates and maintains a policy database about the traffic optimization policies, which includes: intra-operators network traffic localization; inter-operator traffic minimization; real-time application performance optimization; link congestion minimization. 7.2.2 Optimization policy processing functional entity (OPP-FE) OPP-FE performs the following functions: It collects static topology information and node property information fr
