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COM 13 – C 1174 – E
/ INTERNATIONAL TELECOMMUNICATION UNION / COM 13 – C 1174 – ETELECOMMUNICATION
STANDARDIZATION SECTOR
STUDY PERIOD 2009-2012 / October 2011
English only
Original: English
Question(s): / 12/13
STUDY GROUP 13 – CONTRIBUTION 1174
Source: / ETRI
Title: / Revised Draft Recommendation Y.NGN-Web (Functional Requirements and Architecture of Web Service Component in NGN)
This contribution is the revised document of Draft Recommendation Y.NGN-Web based on the output document (TD 733 (NGN-GSI)) of NGN-GSIevent held in Geneva on May 2011.
In this meeting, we would carefully review this revised text for further enhancement in order to request the consent of this document at the next meeting.
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Draft Recommendation Y.NGN-Web
Functional Requirements and Architecture of Web Service Component in NGN
Summary
This draft Recommendation providesfunctional requirements and architecture ofweb service component using web technologies in NGN. For this, this draft Recommendation describes requirements,capabilities and functional architectureof web service component in NGN.
Keywords
NGN, Web
Contents
1. Scope
2. References
3.Definitions
3.1Terms defined elsewhere:
3.2Terms defined in this Recommendation:
4.Abbreviations and acronyms
5.Conventions
6. Requirements for web service in NGN
7. High-level service control architecture for web
7.1 Web service component
7.2 NGN architecture with web service component
7.3 Services classification using web service component
8. Interactions with web service component
8.1Interactions for the support of legacy Internet services
8.2Interactions for the support of web-based conversation services
8.3Interactions for the support of web-based streaming services
9. Functional architecture
9.1 Functional entities for web service component
9.2 Web service control function (WSCF)
9.3 Web media function (WMF)
10. Security considerations
Appendix I NGN service specific components in NGN architecture
Appendix II Relationship with functions defined in ITU-T Recommendations
Appendix III Information flows for services using web service component in NGN
1. Scope...... 4
2. References...... 4
3.Definitions...... 5
3.1Terms defined elsewhere:...... 5
3.2Terms defined in this Recommendation:...... 5
4.Abbreviations and acronyms...... 5
5.Conventions...... 6
6. Requirements and capabilities for web service in NGN...... 7
6.1 Requirements for web service in NGN...... 7
6.2 Capabilities for web service in NGN...... 8
7. High-level service control architecture for Web...... 8
7.1 Web service component...... 8
7.2 NGN architecture with web service component...... 8
7.3 Services classification using web service component...... 9
8. Interactions with web service component...... 10
8.1Interactions for the support of legacy Internet services...... 10
8.2Interactions for the support of web-based conversation services...... 11
8.3Interactions for the support of web-based streaming services...... 11
9. Functional architecture...... 12
9.1 Functional entities for web service component...... 12
9.2 Web service control function (WSCF)...... 13
9.3 Web media function (WMF)...... 14
10. Security considerations...... 14
Appendix I NGN service specific components in NGN architecture...... 15
Appendix II Mapping of related functions between ITU-T Recommendations and Y.NGN-Web18
Appendix III NGN-Web convergence...... 19
Appendix IV Common component and functionalities related to web service component...... 21
Appendix V Information flows for services using web service component in NGN...... 24
Draft Recommendation Y.NGN-Web
Functional Requirements and Architecture of Web Service Component in NGN
1. Scope
The objective of this draft recommendation is to describe functional requirements and architecture ofweb service component in NGN using web technologies such as HTML, HTTP, XML, SOAP, REST and so on. The web service component in NGN basically supports legacy Internet services such as web-browsing, e-mail, blogging, web-office services and etc., and converged NGN services such as web-based conversational services using IP multimedia service component and web-based multimedia streaming service using IPTV services component.
The scope of this draft Recommendationincludes:
Requirements and capabilities for web service in NGN;
Web service component in the support of legacy Internet services and converged NGN services;
Functional architecture for web service component in NGN.
This draft Recommendation mainly focuses on service controland content delivery functions ofin service stratum inof NGN. Detailed web technologies are out of scope.
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 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 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.101]ITU-T Recommendation Y.101 (2000), Global Information Infrastructure terminology: Terms and definitions
[ITU-T Y.1901]ITU-T Recommendation Y.1901 (2009), Requirements for the support ofIPTV services
[ITU-T Y.1910]ITU-T Recommendation Y.1910 (2008), IPTV functional architecture
[ITU-T Y.2007]ITU-T Recommendation Y.2007 (2010), NGN capabilitys Set 2
[ITU-T Y.2011]ITU-T Recommendation Y.2011 (2004), General principles and general reference model for Next Generation Networks
[ITU-T Y.2012]ITU-T Recommendation Y.2012 (2010), Functional requirements and architecture of next generation networks
[ITU-T Y.2021]ITU-T Recommendation Y.2021 (2006), IMS for Next Generation Networks
[ITU-T Y.2031]ITU-T Recommendation Y.2031 (2006), PSTN/ISDN emulation architecture
[ITU-T Y.2091]ITU-T Recommendation Y.2091 (2008), Terms and definitions for Next Generation Networks
[ITU-T Y.2201]ITU-T Recommendation Y.2201 (2009), Requirements and capabilities for ITU-T NGN
[ITU-T Y.2235]ITU-T Recommendation Y.2235 (2008), Converged web-browsing service scenarios in NGN
3.Definitions
3.1Terms defined elsewhere:
This Recommendation uses the following terms defined elsewhere:
3.1.1application [ITU-T Y.101]: A structured set of capabilities, which provide value-added functionality supported by one or more services.
3.1.2functional entity[ITU-T Y.2012]: An entity that comprises an indivisible set of specific functions. Functional entities are logical concepts, while groupings of functional entities are used to describe practical, physical implementations.
3.1.3functional architecture[ITU-T Y.2012]: A set of functional entities and the reference points between them used to describe the structure of an NGN. These functional entities are separated by reference points, and thus, they define the distribution of functions.
3.1.4IPTV [ITU-T Y.1901]:Multimedia services such as television/video/ audio/text/graphics/data delivered over IP-based networks managed to support the required level of QoS/QoE, security, interactivity and reliability.
3.1.5NGN service stratum [ITU-T Y.2011]: That part of the NGN which provides the user functions that transfer servicerelated data and the functions that control and manage service resources and network services to enable user services and applications (see also 7.1 [ITU-T Y.2011]).
3.1.6NGN transport stratum [ITU-T Y.2011]: That part of the NGN which provides the user functions that transfer data and the functions that control and manage transport resources to carry such data between terminating entities (see also 7.1 [ITU-T Y.2011]).
3.1.7service [ITU-T Y.2091]: A set of functions and facilities offered to a user by a provider.
3.2Terms defined in this Recommendation:
This Recommendation defines the following terms:
3.2.1converged NGN service: A kind of interworking services with web and NGN such as web-based conversational service using IP multimedia service component and streaming service using IPTV service component.
3.2.2legacy Internet service: A kind of well-known Internet services such as FTP, Telnet, web-browsing, e-mail, blogging, web-office services and etc.
3.2.3web service component: One of NGN service components in NGN service stratum together with IP multimedia service component, IPTV service component and, it enables NGN services to support legacy Internet services and converged NGN services.
4.Abbreviations and acronyms
This Recommendation uses the following abbreviations and acronyms:
APIApplication Programming Interface
CSCFCall Session Control Function
FTPFile Transfer Protocol
HTMLHyper Text Markup Language
HTTPHyper Text Transfer Protocol
IMSIP Multimedia Subsystem
ISDNIntegrated Service Digital Network
MMoIPMultimedia over IP
NACFNetwork Attachment Control Function
PCPersonal Computer
PCC-FEPolicy and Charging Control - Functional Entity
PDAPersonal Digital Assistant
PDFPolicy Decision Function
PSTNPublic Switched Telephone Network
PWC-FEProxy Web Control - Functional Entity
QoSQuality of Service
RACFResource Admission Control Function
REST Representational State Transfer
RTSPReal Time Streaming Protocol
SCIMSmart Common Input Method
SIPSession Initiation Protocol
SOAPSimple Object Access Protocol
VoIPVoice over IP
WMFWeb Media Function
WMGC-FEWeb Media GatewayControl - Functional Entity
WMRC-FEWeb Media Resources Control - Functional Entity
WMT-FEWeb Media Transform - Functional Entity
WSCFWeb Service Control Function
WSDLWeb Service Definition Language
WSGC-FEWeb Signaling Gateway Control - Functional Entity
XMLExtensible Markup Language
5.Conventions
In this Recommendation:
The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed.
The keywords "is prohibited from" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed.
The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance.
The keywords "is not recommended" indicate a requirement which is not recommended but which is not specifically prohibited. Thus, conformance with this Recommendation can still be claimed even if this requirement is present.
The keywords "can optionally" indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendor's 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 this Recommendation.
6. Requirementsand capabilities for web service in NGN
6.1 Requirements for web service in NGN
The NGN has the following general requirements to support web related applications/services.
It is required to provide ‘web-based application support’ satisfying with interoperability across wired and wireless network environment;
The web-based application support enablers allow enhanced utilization of device capabilities and network characteristics for web-based applications[ITU-T Y.2201].
Web-based application support capabilities provide users with a consistent web environment which spans multiple network environments and multiple devices (PC, laptop, smart phonePDA, cell phone, etc.)[ITU-T Y.2201].
It is required to support web-based information and media types including text, audio, image, video and related metadata formats.
It is required to provide the service control functions such as service directory, classification, session management, protocol mapping, billing & charging and etc. on the web.
It is required to provide the media transformation functions such as transcoding, filtering, QoS control and media gateway and etc. on the web.
It is required to support the interaction with existing NGN services & transport control functions such as user profile function in service stratum and RACF, NACF in transport stratum and so on.
The NGN is required to support various types of services using web as follows.
It is required to support legacy Internet services in NGN environment.
A number of well-known Internet services shallare required to be supported in NGN, for instance web-browsing, e-mail, blogging, web-office services and etc.using web technologies.
It is required to support interworking with conversation services using web
NOTE - The service capability interaction manager (SCIM) and Parlay Gateway could be used for conversation services.
NOTE – A protocol interworking between HTTP and SIP is necessary to support Web-based IMS service.
It is required to support interworking with streaming services using web
NOTE - The IPTV media deliverycould be used for streaming services.
6.2 Capabilities for web service in NGN
(Editor’s Note) Related contributions are invited for describing required capabilities.
This clause addresses the required capabilities to support interworking/convergence between NGN and web.
(1) Open service environment
It may be used for interworking between IMS, IPTV and web by enabling open and standard ANIs to accommodate interactions between NGN entities and applications (e.g., for service creation). By utilizing the capability, the portable and/or reusable across networks could be possible.
(2) Interworking
The protocol interworking between HTTP and SIP is necessary to support Web-based IMS service. Thus, interworking gateway is responsible for mapping HTTP/SOAP messages to SIP messages.
7. High-level service control architecture for web
7.1 Web service component
NGN architecture has three service components for service control function: IPTV service component, PSTN/ISDN emulation service component, and IP multimedia service component. Additionally a web service component is newly added into service stratum of NGN architecture to support web related capabilities as shown in Figure 1.
The web service component enables NGN services to support legacy Internet services and converged NGN services. For this, the web service component supports the web standard interfaces and protocols such as HTML, XML, HTTP, SOAP, REST, WSDL and so on.
Figure 1.Web service component in NGN service specific components
7.2NGN architecture with web service component
The Figure 2 shows NGN-Web convergence architectural model for interconnecting NGN and web. The architecture mainly comprises web service control function (WSCF) and web media function (WMF). The WSCF performs adaptation function between the NGN service stratum and the web. The WMF performs interworking between the NGN transport stratum and the web.
In Figure 2, the service components are related to each other and may contain common or shared functionality.
Figure 2. NGN architecture with web service component
7.3Services classification using web service component
NGN should support multi-service capabilities which support various composition services simultaneously. The network requires networking environment with NGN/web convergence.
According to different service control, web service in NGN can be classified as follows.
Legacy Internet services (Pure Web Services): A kind of well-known Internet services using web in NGN environment such as web-browsing, e-mail, blogging, web-office services and etc.
Converged NGN services: A kind of interworking services with web and NGN
Web-based IMS services (e.g., MMoIP using web)
Web-based IMS services using interworking with IP multimedia service component
Web-based streaming services (e.g., IPTV using web)
Web-based streaming services using interworking with IPTV service component
Web-based composition services (e.g., MMoIP + IPTV using web)
Composition services both web service component and interworking with other service components
Figure 3 depictsrelated service components for various kinds of web service in NGN. Web service component interacts with IPTV service component as well as IP multimedia service component for converged NGN services.Common componentfunctionalitiesisare a group of functional entities which are specified in other service component.
Figure 3. Service classification according to different service control
(Editor’s Note) Based on our discussion, we had decided to change the “common component” into “common functionalities” or other appropriate terms. In this regards, other text (e.g., Appendix IV) should be modified.
Appendix IV describes common component and functionalities related to web service component in detail.
8. Interactionswithweb service component
This section introduces the interactions among relevant functions to provide web services as well as web based services.
8.1Interactionsfor the support of legacy Internet services
End user requests an Internet service to web service control functions, utilizing HTTP protocol to communicate with web server. At next, web service control functions determine an appropriate web server to provide the request service with directory by referringservice user profile functions. The web server makes an Internet service by transferringservice response message to end user. At this time, web media functions can transcode the media data in web page into an appropriate format to end user’s device, if the web server cannot support the requested format from end user.
Figure 4. Legacy Internet services using web service component
8.2Interactionsfor the support of web-based conversation services
End user requests a conversation service to web service control functions, utilizing HTTP protocol to communicate with IP multimediaservice component. IP multimediaservice component makes a conversation service by a method of calling relevant APIs to interact with IMS call server and then responds to the service request from end user. At this time, web media functions can transcode the media data into an appropriate format to end user, if IMS call server cannot support the requested codec from end user.
Figure 5. Web-based conversation services using web service component
8.3Interactionsfor the support of web-based streaming services
End user requests a streaming service to web service control functions, utilizing HTTP protocol to communicate with IPTV service component. IPTV service component makes a streaming service by delivering video streaming to end user. At this time, web media functions can transcode the media data into an appropriate format to end user, if IPTV service component cannot support the requested video streaming format from end user.