1、 International Telecommunication Union ITU-T Y.2206TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (04/2010) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Service aspects: Service capabilities and service architecture Req
2、uirements for distributed service networking capabilities Recommendation ITU-T Y.2206 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.
3、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 and applications Y.1100Y.1199 A
4、rchitecture, 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
5、.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.2249Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Nu
6、mbering, naming and addressing Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Future networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 For further details, please refer to t
7、he list of ITU-T Recommendations. Rec. ITU-T Y.2206 (04/2010) i Recommendation ITU-T Y.2206 Requirements for distributed service networking capabilities Summary Recommendation ITU-T Y.2206 specifies requirements for distributed service networking (DSN) capabilities. The main objective of this Recomm
8、endation is to provide guidance regarding the design of networks, services and applications making use of DSN. History Edition Recommendation Approval Study Group 1.0 ITU-T Y.2206 2010-04-30 13 ii Rec. ITU-T Y.2206 (04/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nati
9、ons 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 Recommendations
10、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 approval of
11、 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 “Administration“ is
12、 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 compliance with
13、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 required
14、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 Intellectual
15、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 Recommendation. However
16、, 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 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior
17、 written permission of ITU. Rec. ITU-T Y.2206 (04/2010) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Terms and definitions . 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 High level requirements for DSN capabilities 3 6
18、.1 Routing . 3 6.2 Numbering, naming and addressing . 4 6.3 Load balancing . 4 6.4 Scalability . 4 6.5 Fault tolerance 4 6.6 Mobility support and service continuity . 4 6.7 Quality of service . 4 6.8 Interworking . 5 6.9 Accounting in the distributed environment 5 6.10 OAM in the distributed environ
19、ment . 5 6.11 Traffic and topology awareness 5 6.12 Traffic optimization 5 6.13 Bandwidth management . 6 6.14 Terminal support 6 6.15 Resource contribution and usage management 6 6.16 Heterogeneity support 6 6.17 Adaptability to service and network environment 6 6.18 Dynamic DSN infrastructure resou
20、rce scheduling . 6 6.19 Open service interface 7 6.20 Content distribution management . 7 6.21 Accumulation of transferred fragmented content . 7 6.22 Distributed storage and lookup . 7 7 Security considerations . 8 Bibliography. 9 Rec. ITU-T Y.2206 (04/2010) 1 Recommendation ITU-T Y.2206 Requiremen
21、ts for distributed service networking capabilities 1 Scope This Recommendation specifies requirements for distributed service networking (DSN) capabilities necessary to guide the design of networks, services and applications supported through the use of DSN. The specific mapping of requirements for
22、DSN capabilities into requirements for existing and extended NGN capabilities is out of scope of this Recommendation. 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 t
23、ime 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 Recommendations and other references listed below.
24、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 Q.1706 Recommendation ITU-T Q.1706/Y.2801 (2006), Mobility management requirements for
25、 NGN. 3 Terms and definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 application b-ITU-T Y.101: A structured set of capabilities, which provide value-added functionality supported by one or more services. 3.1.2 control plane b-ITU-T Y.2011:
26、The set of functions that controls the operation of entities in the stratum or layer under consideration, plus the functions required to support this control. 3.1.3 data plane b-ITU-T Y.2011: The set of functions used to transfer data in the stratum or layer under consideration. 3.1.4 overlay networ
27、k b-ITU-T Y-Sup.10: A network of nodes and logical links that is built on top of the underlying, e.g., transport, network with the purpose of providing network service that is not available in the underlying network. 3.1.5 personal mobility ITU-T Q.1706: This is the mobility for those scenarios wher
28、e the user changes the terminal used for network access at different locations. The ability of a user to access telecommunication services at any terminal on the basis of a personal identifier, and the capability of the network to provide those services delineated in the users service profile. 3.1.6
29、 service b-ITU-T Y.101: A structure set of capabilities intended to support applications. 3.1.7 service provider b-ITU-T M.1400: A general reference to an operator that provides telecommunication services to customers and other users either on a tariff or contract basis. A service provider may or ma
30、y not operate a network. A service provider may or may not be a customer of another service provider. See 1.4.6/M.3320. 2 Rec. ITU-T Y.2206 (04/2010) 3.1.8 terminal mobility b-ITU-T Q.1703: The ability of a terminal to access telecommunication services from different locations and while in motion, a
31、nd the capability of the network to identify and locate that terminal. Terminal mobility can be further classified into: continuous terminal mobility (handover) and discrete terminal mobility (roam). 3.1.9 trust b-ITU-T Y.2701: Entity X is said to trust entity Y for a set of activities if and only i
32、f entity X relies upon entity Y behaving in a particular way with respect to the activities. 3.1.10 user b-ITU-T Y.2091: A user includes end user, person, subscriber, system, equipment, terminal (e.g., FAX, PC), (functional) entity, process, application, provider, or corporate network. 3.2 Terms def
33、ined in this Recommendation This Recommendation defines the following terms: 3.2.1 core DSN node: A DSN node deployed in the service provider domain. 3.2.2 distributed service networking (DSN): An overlay networking which provides distributed and manageable capabilities to support various multimedia
34、 services and applications. 3.2.3 DSN node: A node used in DSN providing distributed functionalities, including distributed routing and distributed storage. NOTE The node can be seen as a set of functions grouped together. 3.2.4 peer-to-peer (P2P): A system is considered to be P2P if the nodes of th
35、e system share their resources in order to provide the service the system supports. The nodes in the system both provide services to other nodes and request services from other nodes. 3.2.5 user DSN node: A DSN node in the user domain, e.g., a PC, mobile terminal, etc. 4 Abbreviations and acronyms T
36、his Recommendation uses the following abbreviations and acronyms: API Application Programming Interface DSN Distributed Service Networking IMS IP Multimedia Subsystem IP Internet Protocol NAT Network Address Translation NGN Next Generation Network OAM Operation, Administration and Maintenance P2P Pe
37、er-to-Peer PSTN Public Switched Telecommunications Network QoS Quality of Service SLA Service Level Agreement VoIP Voice over Internet Protocol WLAN Wireless Local Area Network Rec. ITU-T Y.2206 (04/2010) 3 5 Conventions In this Recommendation: The phrase “is required to“ indicates a requirement whi
38、ch must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. The phrase “is prohibited from“ indicates a prohibition which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to b
39、e claimed. The phrase “is recommended“ indicates a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be satisfied to claim conformance. The phrase “is not recommended“ indicates a requirement which is not recommended but which is not specifically
40、prohibited. Thus, conformance with this Recommendation can still be claimed even if this requirement is satisfied. The phrase “can optionally“ indicates an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendors
41、implementation 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 Recommendation. A DSN service provider is to be understood as a service provi
42、der that makes use of DSN in order to provide services and applications to its users. 6 High level requirements for DSN capabilities DSN is based upon the use of a collection of nodes organized in a peer-to-peer (P2P) or other distributed fashion and the links between the nodes for the purpose of en
43、abling multimedia services and applications. It is assumed that DSN is an overlay above IP. Collectively, the nodes provide a distributed mechanism. DSN also provides capabilities for application layer QoS support. The high level requirements for DSN capabilities are provided in the following clause
44、s. 6.1 Routing 6.1.1 DSN is required to support routing in the control plane using distributed mechanisms, such as those based upon P2P techniques. NOTE P2P-based routing mechanisms are used for node searching: locating the called parties, requested contents, etc. 6.1.2 DSN is required to offer data
45、-plane routing optimization using distributed mechanisms, such as those based upon P2P techniques. NOTE 1 Different applications have different data-plane routing requirements; e.g., VoIP requires low latency and jitter; downloading needs high throughput and high QoS and video conferencing needs bot
46、h. NOTE 2 To meet these different requirements, P2P technology can offer better-than-best-effort routing, which is hard to realize in the native IP network, by the use of application layer routing optimization. For example, sometimes the routing path selected may be congested and one DSN node will b
47、e selected to perform a relay function to establish a new path, so as to improve the QoS. 6.1.3 DSN is required to support NAT traversal between DSN nodes separated by one or more NATs. 6.1.4 DSN is recommended to support multicasting of content. NOTE Multicasting capability efficiently utilizes the
48、 network resources in delivering content to multiple receivers. 6.1.5 DSN is recommended to support multipath distributed routing, which includes delivery of the same traffic from one DSN node to another DSN node via different paths. 4 Rec. ITU-T Y.2206 (04/2010) NOTE This support includes routing b
49、ased on user DSN node information that provides optimized delivery according to the location and heterogeneity (such as in terms of supported access technologies) of DSN nodes. 6.2 Numbering, naming and addressing 6.2.1 DSN is required to provide numbering, naming and addressing capability of DSN nodes. 6.2.2 DSN is required to support the separation of the DSN node network address and the DSN node identifier. 6.2.3 DSN is recommended to provide mapping between a DSN node network address and a DSN node identif
