1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T H.510TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2002) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSMobility and Collaboration procedures Mobility for H-Series multimedia systems and services Mobility for H.323 multimedia systems and services ITU-T
2、 Recommendation H.510 ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS H.100H.199 INFRASTRUCTURE OF AUDIOVISUAL SERVICES General H.200H.219 Transmission multiplexing and synchronization H.220H.229 Systems aspects H.230H.239 Communication p
3、rocedures H.240H.259 Coding of moving video H.260H.279 Related systems aspects H.280H.299 SYSTEMS AND TERMINAL EQUIPMENT FOR AUDIOVISUAL SERVICES H.300H.399 SUPPLEMENTARY SERVICES FOR MULTIMEDIA H.450H.499 MOBILITY AND COLLABORATION PROCEDURES Overview of Mobility and Collaboration, definitions, pro
4、tocols and procedures H.500H.509 Mobility for H-Series multimedia systems and services H.510H.519 Mobile multimedia collaboration applications and services H.520H.529 Security for mobile multimedia systems and services H.530H.539 Security for mobile multimedia collaboration applications and services
5、 H.540H.549 Mobility interworking procedures H.550H.559 Mobile multimedia collaboration inter-working procedures H.560H.569 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. H.510 (03/2002) i ITU-T Recommendation H.510 Mobility for H.323 multimedia systems and servic
6、es Summary The purpose of this Recommendation is to define services and procedures for the support of mobility in H.323 multimedia systems. Source ITU-T Recommendation H.510 was prepared by ITU-T Study Group 16 (2001-2004) and approved under the WTSA Resolution 1 procedure on 29 March 2002. Keywords
7、 H.323, multimedia systems, terminal mobility, user mobility. ii ITU-T Rec. H.510 (03/2002) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent or
8、gan 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 years, establishes the
9、 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 necessary standards are
10、 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. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that th
11、e 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 members or others outside of the Recommendation
12、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, implementors are cautioned that this may not represent the latest information and are t
13、herefore strongly urged to consult the TSB patent database. ITU 2002 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. H.510 (03/2002) iii CONTENTS Page 1 Scope 1 2 References 1 2.1 Normative reference
14、s . 1 2.2 Informative references 1 3 Definitions 1 4 Symbols and abbreviations. 3 5 H.323 mobility service description. 4 5.1 General description. 4 5.1.1 H.323 user mobility 4 5.1.2 H.323 terminal mobility . 5 5.1.3 Service mobility . 5 5.2 H.323 requirements 5 5.2.1 Requirements for H.323 user mob
15、ility. 5 5.2.2 Requirements for H.323 terminal mobility 6 5.2.3 Mobility identification requirements 6 5.3 Procedures required for mobility management 8 5.4 Procedures required for provisioning and configuring H.323 mobile entities 8 6 Architecture for H.323 mobility . 8 6.1 Architectural model 8 6.
16、2 Functional entities 9 6.2.1 Mobility specific entities 9 6.2.2 H.323 mobile terminal 9 6.2.3 Gatekeeper and border element 10 6.3 Reference points. 10 7 Mobility management procedures 11 7.1 General on mobility management procedures 11 7.2 Example scenarios for mobility management procedures 11 7.
17、3 HLF Address space announcement procedures 12 7.3.1 Static arrangement 12 7.3.2 Dynamic arrangement 12 7.3.3 Address patterns . 12 7.4 Location update procedures 13 7.4.1 Gatekeeper discovery . 13 iv ITU-T Rec. H.510 (03/2002) Page 7.4.2 Registration 14 7.4.3 Unregistration. 15 7.4.4 Information fl
18、ows for the location updating procedures 15 7.4.5 Unregistration. 18 7.5 Call establishment mobility management procedures 22 7.5.1 General principles. 22 7.5.2 Call establishment mobility management procedures for incoming calls 22 7.5.3 Call establishment mobility management procedures for outgoin
19、g calls. 25 7.5.4 Security. 26 7.6 Handover 26 ITU-T Rec. H.510 (03/2002) 1 ITU-T Recommendation H.510 Mobility for H.323 multimedia systems and services 1 Scope This Recommendation deals with mobility aspects for H.323 systems above the transport layer. H.510 applies new functions defined in suppor
20、t of mobility management to H.323-compliant systems. The main focus is on the support of terminal mobility, although support of user mobility in the context of H.323 is covered as well. This version of this Recommendation does not cover handover procedures where active calls can be maintained during
21、 location changes. Interworking with other networks to support mobility across networks of different types is outside the scope of this Recommendation. 2 References 2.1 Normative references The following ITU-T Recommendations and other references contain provisions which, through reference in this t
22、ext, 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
23、 of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. 1 ITU-T Recommendation H.323 (2000), Packet-based multimedia communications systems. 2 ITU-T Recommendation H.225.0 (2000), Call signalling protocols and media strea
24、m packetization for packet-based multimedia communication systems. 3 ITU-T Recommendation H.225.0 Annex G (1999), Communication between administrative domains. 4 ITU-T Recommendation H.501 (2002), Protocol for mobility management and intra/inter-domain communication in multimedia systems. 5 ITU-T Re
25、commendation H.530 (2002), Symmetric security procedures for H.510 (Mobility for H.323 multimedia systems and services). 2.2 Informative references IETF RFC 2486 (1999), The Network Access Identifier. 3 Definitions For the purposes of this Recommendation, the definitions given in ITU-T Rec. H.323 sh
26、all apply, with the following additions. 3.1 administrative domain: Defined as in H.225.0 Annex G. An administrative domain consists of one or more zones. 3.2 callable user identity: A user identity that can be used by a calling user to make a call to the user identified by this user identity. It ma
27、y be announced e.g. in a phonebook as the identity by which a user can be reached. 2 ITU-T Rec. H.510 (03/2002) 3.3 H.323 point of attachment: A network point of attachment that allows the H.323 terminal to register with a gatekeeper or to directly communicate with another H.323 terminal. 3.4 home d
28、omain: The administrative domain that is related by subscription to the mobile user. The home domain contains user-specific data including location, authentication, and service profile information related to the mobile user. 3.5 home gatekeeper (Home GK): A gatekeeper in the home domain of a user. 3
29、.6 home service provider: The service provider or administrator in charge of the home domain of a user; i.e. the user is related to the home service provider by a subscription contract. 3.7 location: The network point of attachment through which the user/terminal is currently accessing the H.323 sys
30、tem. 3.8 H.323 mobile terminal: A terminal that may change H.323 point of attachment. 3.9 mobility management: The set of functions needed to provide user, terminal and service mobility. 3.10 network point of attachment: The network interface that is used by an endpoint in order to access the H.323
31、system. Each network point of attachment is associated with a network address (e.g. IP address) by which packets sent to the endpoint reach the endpoint. 3.11 online: State of a mobile user or terminal that has “logged on“, i.e. is currently registered at a gatekeeper, as opposed to absent or “logge
32、d off“. 3.12 primary user identity: The user identity allocated permanently to a user at subscription time, which stays the same as long as the subscription exists. There is only one primary user identity for a user. 3.13 service mobility: The ability of a user to use the particular (subscribed) ser
33、vice irrespective of the location of the user and the terminal that is used for that purpose. 3.14 serving domain: The (visited or home) administrative domain that is serving an online mobile user/terminal. 3.15 serving gatekeeper: The (visited or home) gatekeeper where an online mobile user/termina
34、l is currently registered. 3.16 temporary user identity: A user identity allocated to a user on a temporary basis which is intended to be used in place of the primary user identity, for example because of security reasons. 3.17 terminal identity: A code or string uniquely identifying a terminal. NOT
35、E One possible use is to authenticate the terminal during the user registration. The terminal authentication permits to verify whether or not the user is allowed to use the terminal (for instance if the H.323 mobile terminal is “black-listed“ by the home service provider e.g. after having been stole
36、n the mobile user cannot register in the H.323 network with this terminal). 3.18 terminal mobility: The ability of a terminal to change location (i.e. network point of attachment and H.323 point of attachment) and still be able to communicate. 3.19 discrete terminal mobility (terminal roaming): The
37、ability of a terminal to make discrete changes of location, i.e. to change location while no media streams are active. 3.20 continuous terminal mobility (handover): The ability of a terminal to change location while media streams are active. Handover is further called seamless when the terminal loca
38、tion change does not result in delay or loss of data that would be perceived by the user as degradation of quality of service (note that seamless handovers may depend on many factors, including service type and service presentation robustness against data loss at the terminal). 3.21 user: A person o
39、r other entity authorized to use H.323 communication services. ITU-T Rec. H.510 (03/2002) 3 3.22 user identity: A code or string uniquely identifying a user across a multi-user, multi-service infrastructure. 3.23 user mobility (personal mobility): The ability of a user to maintain the same user iden
40、tity irrespective of the terminal used and its network point of attachment. Terminals used may be of different types. 3.24 discrete user mobility (user roaming): The ability of a user to change location or terminals while no media streams are active. 3.25 continuous user mobility (session mobility):
41、 The ability of a user to change location or terminals while media streams are active. NOTE A similar feature is provided in the SCN by the supplementary service Terminal Portability. 3.26 user service profile: User-specific information indicating which services a user is subscribed to and personal
42、configuration data for the respective services. 3.27 visited domain: The administrative domain that is not the home domain and is serving a mobile user. 3.28 visited gatekeeper (Visited GK): A gatekeeper in a visited domain. 4 Symbols and abbreviations This Recommendation uses the following abbrevia
43、tions: A Address (as a DNS record/query type) AuF Authentication Function BE Border Element DHCP Dynamic Host Configuration Protocol DNS Domain Name System e164 Address type “phone number“ (according to ITU-T Rec. E.164) EP Endpoint GK Gatekeeper HLF Home Location Function IMSI International Mobile
44、Subscriber Identity IP Internet Protocol MT Mobile Terminal NAI Network Access Identifier NPoA Network Point of Attachment RAS Registration, Admission and Status protocol (ITU-T Rec. H.225.0) The following RAS messages are used in this Recommendation: ACF AdmissionConfirm ARJ AdmissionReject ARQ Adm
45、issionRequest GCF GatekeeperConfirm GRJ GatekeeperReject 4 ITU-T Rec. H.510 (03/2002) GRQ GatekeeperRequest LCF LocationConfirm LRQ LocationRequest RCF RegistrationConfirm RIP RequestInProgress RRJ RegistrationReject RRQ RegistrationRequest SLA Service Level Agreement SRV Service (as a DNS record/qu
46、ery type) TSAP Transport Service Access Point TXT Text (as a DNS record/query type) UCF UnregistrationConfirm UIM User Identification Module URL Universal Resource Locator URQ UnregistrationRequest VLF Visitor Location Function 5 H.323 mobility service description The following clauses define the se
47、rvices the H.323 system provides for terminal and user mobility. These are overall service descriptions from a users point of view without dealing with the user interface aspects themselves. 5.1 General description 5.1.1 H.323 user mobility This Recommendation deals with the support of mobile users
48、that belong to an H.323 network. NOTE General user mobility is described in other Recommendations. In a network supporting user mobility there exists a dynamic association between mobile users and terminals. Any mobile user can register at any terminal with access to the network, within the limits o
49、f applicable permissions. Registration enables the mobile user to obtain the services permitted by the applicable user service profile and supported at the currently used terminal. A change of location results in a new registration of the mobile user and the corresponding de-registration from the previous location (if there was one). A mobile user belongs permanently to exactly one administrative domain, the home domain of that user. User mobility may be restricted to the home domain, or may be permitted across multiple administrative domains subject
