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.2041 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2017) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS, NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES Next Generation Networks
2、 Frameworks and functional architecture models Policy control mechanism in multi-connection Recommendation ITU-T Y.2041 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS, NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES GLOBAL INFORMATION INFRAS
3、TRUCTURE General Y.100Y.199 Services, applications 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 A
4、SPECTS General Y.1000Y.1099 Services and 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, administratio
5、n and maintenance Y.1700Y.1799 Charging 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 aspe
6、cts: Interoperability of services and networks 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 e
7、nvironment Y.2900Y.2999 FUTURE NETWORKS 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 Framewo
8、rks, architectures and protocols Y.4400Y.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 R
9、ecommendations. Rec. ITU-T Y.2041 (03/2017) i Recommendation ITU-T Y.2041 Policy control mechanism in multi-connection Summary Recommendation ITU-T Y.2041 describes a policy control mechanism in multi-connection. Recommendation ITU-T Y.2041 also covers scenarios, requirements, solutions and informat
10、ion flows. Multi-connection architecture is designed for heterogeneous networks, has the ability to provide multi-connection user equipment (MUE) and networks the functionality to maintain more than one access network connection simultaneously. It controls policies, flows, quality of service (QoS),
11、etc. Policy control is useful or even necessary for multi-connection. Policy control determines how to use multiple access network connections. There can be several policies in multi-connection, such as those for QoS and service transfer. Recommendation ITU-T Y. 2041 provides a coordination mechanis
12、m to ensure that all policies work together in a coherent manner for multi-connection. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T Y.2041 2017-03-29 13 11.1002/1000/13248 Keywords Multi-connection, policy control * To access the Recommendation, type the URL http:/handle.
13、itu.int/ in the address 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.2041 (03/2017) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of tele
14、communications, 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 on them with a view to standardizing teleco
15、mmunications 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 ITU-T Recommendations is covered by the pr
16、ocedure 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 used for conciseness to indicate both a te
17、lecommunication 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 the Recommendation is achieved when all of
18、 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 of any party. INTELLECTUAL PROPERTY RIGHTS
19、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 Property Rights, whether asserted by ITU me
20、mbers 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, implementers are cautioned that this may
21、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 2017 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.20
22、41 (03/2017) iii Table 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 . 1 4 Abbreviations and acronyms 2 5 Conventions 2 6 Requirements 3 6.1 Overview 3 6.2 Requirements 3 7 Policy control mechanism. 5 7.1 Function
23、ality entities of multi-connection policy control 5 7.2 Description of the mechanism 6 7.3 Procedures 8 Bibliography. 11 Rec. ITU-T Y.2041 (03/2017) 1 Recommendation ITU-T Y.2041 Policy control mechanism in multi-connection 1 Scope This Recommendation describes scenarios, requirements, solutions and
24、 information flows for policy control in multi-connection. NOTE Security and charging requirements for policy control in multi-connection are addressed in b-ITU-T Y.2251. 2 References None. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.
25、1 connection b-ITU-T X.200: A connection is an association established for the transfer of data between two or more peer-(N)-entities. This association binds the peer-(N)-entities together with the (N1)-entities in the next lower layer. 3.1.2 multi-connection b-ITU-T Y-Sup.9: Multi-connection is the
26、 collection of several simultaneous connections between two or more peer-(N)-entities. At least one of the connections is required to be associated with a physical layer connection different from the rest of the connections. All connections are dynamically coordinated with each other by the subscrib
27、er or the network to provide service to higher layer entities. 3.1.3 IP-CAN session b-3GPP TS 23.203: The association between a UE and an IP network. The association is identified by one IPv4 and/or an IPv6 prefix together with UE identity information, if available, and a PDN represented by a PDN ID
28、 (e.g., an APN). An IP-CAN session incorporates one or more IP-CAN bearers. Support for multiple IP-CAN bearers per IP-CAN session is IP-CAN specific. An IP-CAN session exists as long as UE IP addresses/prefix are established and announced to the IP network. 3.1.4 policy control b-3GPP TS 23.203: Th
29、e process whereby the PCRF indicates to the PCEF how to control the IP-CAN session. Policy control includes QoS control and/or gating control. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 enhanced policy and charging enforcement function (ePCEF): A
30、function that addresses the enhanced requirements of the policy and charging enforcement function (PCEF) to support multi-connection related policy control enforcement function. The PCEF is a logical entity that enforces policy decisions. The PCEF is responsible for traffic policy enforcement of uni
31、cast traffic. Policy enforcement may be applied at an Internet protocol (IP) session, IP flow and aggregate level. 3.2.2 enhanced policy and charging rule function (ePCRF): A function that addresses the enhanced requirements of the policy and charging rule function (PCRF) to support multi-connection
32、 related policy and charging rule function. The PCRF is a functional entity making policy decisions for network control, gating, quality of service (QoS) and charging. Such policy decisions are based 2 Rec. ITU-T Y.2041 (03/2017) on subscriber preferences and are applied on an Internet protocol (IP)
33、 session, IP flows or aggregate flows basis. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: 2G second Generation 3G third Generation APN Access Point Name ePCEF enhanced Policy and Charging Enforcement Function ePCRF enhanced Policy and Charging Rule
34、Function FSC Flow-based Service Continuity ID Identification IP Internet Protocol IP-CAN IP Connectivity Access Network IPv4 Internet Protocol version 4 IPv6 Internet Protocol version 6 LTE Long-Term Evolution MC-FE Multi-connection Coordination Functional Entity MMF Multi-connection Media Function
35、MPC-FE Multi-connection Policy Control Functional Entity MUE Multi-connection User Equipment MUP-FE Multi-connection User Profile Functional Entity OTT Over the Top PCEF Policy and Charging Enforcement Function PCRF Policy and Charging Rule Function PDN Packet Data Network QoS Quality of Service RAT
36、 Radio Access Technology SCF Service Control Function TV Television UE User Equipment WLAN Wireless Local Area Network 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
37、 this document is to be claimed. Rec. ITU-T Y.2041 (03/2017) 3 The keywords “is prohibited from“ indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. The keywords “is recommended“ indicate a requirement whic
38、h 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 specification can still be cl
39、aimed 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 vendors implementation must provide the option and the feature can be optionall
40、y enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. 6 Requirements 6.1 Overview Policy control is useful or even necessary for multi-connection. Policy control determines how to use mul
41、tiple access network connections, there can be several policies in multi-connection, such as those for QoS and service transfer. It is necessary to have a coordination mechanism to ensure that all policies work together in a coherent manner for multi-connection. For example, QoS policies match the s
42、ervice to the access network to ensure proper QoS for application and services while service transfer policies control multi-connection network flow transfer during access to a different network. Generally, the multiple policy control mechanism requires combination in a multi-connection service acti
43、on, such as multi-connection service transfer. In terms of related scenarios, consider that, in a video conference or over the top (OTT) video TV at home, the user equipment (UE) accesses heterogeneous access networks, the audio is transmitted by 2G, 3G or long-term evolution (LTE) to assure real ti
44、me service and the video is transmitted by a wireless local area network (WLAN). After a while, we leave home with the service active, but we lose the WLAN connection, we need to transfer the video flow to a 3G or LTE connection, in this process, consider the multiple policy control combination and
45、coordination to serve the application. In this scenario, the application contains policies relating to access selection, service transfer, QoS and others. So, a coordination mechanism is required to ensure that all policies work together in a coherent manner. 6.2 Requirements 6.2.1 General requireme
46、nts The following elements describe the general requirement. The ePCRF should be able to send policies to the ePCEF. The ePCRF should be able to provision policy rules at ePCEF based on a request from the ePCEF (PULL mode), or based on a request from the service control function (SCF), a timer expir
47、ation or a subscription profile modification (PUSH mode). The ePCEF should be able to initiate, modify and terminate the IP-CAN session. The ePCEF should be able to request policies from the ePCRF. The PCEF should be able to receive policies from the ePCRF. The ePCEF should be able to apply policies
48、 to subscriber IP-CAN sessions. The ePCEF should be able to enforce policy for multi-connection traffic. 4 Rec. ITU-T Y.2041 (03/2017) The ePCEF should support policy enforcement for both downstream and upstream traffic. The ePCEF should acknowledge the reception of policies from the ePCRF. The ePCE
49、F should be able to activate or deactivate pre-provisioned policies per list received from the ePCRF. The ePCEF should be able to give precedence to the policies provided by the ePCRF over the others. If the ePCRF is not available at the time of subscriber or host instantiation, the ePCEF should be able to provide the subscriber or host with default policies. 6.2.2 Requirements for quality of service control If the QoS information contained in a policy rule is applicable to the multi-connection s
