1、 International Telecommunication Union ITU-T Series QTELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 57(01/2008) SERIES Q: SWITCHING AND SIGNALLING Signalling requirements to support the emergency telecommunications service (ETS) in IP networks ITU-T Q-series Recommendations Supplement 57
2、 ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE Q.1Q.3 INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Q.4Q.59 FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.60Q.99 CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS Q.100Q.119 SPECIFIC
3、ATIONS OF SIGNALLING SYSTEMS No. 4, 5, 6, R1 AND R2 Q.120Q.499 DIGITAL EXCHANGES Q.500Q.599 INTERWORKING OF SIGNALLING SYSTEMS Q.600Q.699 SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 Q.700Q.799 Q3 INTERFACE Q.800Q.849 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 Q.850Q.999 PUBLIC LAND MOBILE NETWORK Q.10
4、00Q.1099 INTERWORKING WITH SATELLITE MOBILE SYSTEMS Q.1100Q.1199 INTELLIGENT NETWORK Q.1200Q.1699 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q.1700Q.1799 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) Q.1900Q.1999 BROADBAND ISDN Q.2000Q.2999 SIGNALLING REQUIRE
5、MENTS AND PROTOCOLS FOR THE NGN Q.3000Q.3999 For further details, please refer to the list of ITU-T Recommendations. Q series Supplement 57 (01/2008) i Supplement 57 to ITU-T Q-series Recommendations Signalling requirements to support the emergency telecommunications service (ETS) in IP networks Sum
6、mary This supplement identifies the signalling requirements to support preferential capabilities within IP networks for the emergency telecommunications service (ETS). Source Supplement 57 to ITU-T Q-series Recommendations was agreed on 23 January 2008 by ITU-T Study Group 11 (2005-2008). ii Q serie
7、s Supplement 57 (01/2008) 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) is a permanent organ of ITU. ITU
8、-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 topics for stu
9、dy 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 prepared on a
10、collaborative basis with ISO and IEC. NOTE In this publication, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this publication is voluntary. However, the publication may contain certain m
11、andatory provisions (to ensure e.g., interoperability or applicability) and compliance with the publication 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. Th
12、e use of such words does not suggest that compliance with the publication is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this publication may involve the use of a claimed Intellectual Property Right. ITU takes no p
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14、d by patents, which may be required to implement this publication. 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.int/ITU-T/ipr/. ITU 2008 All rights reserved. No part of this
15、 publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Q series Supplement 57 (01/2008) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 1 4 Abbreviations and acronyms 1 5 General aspects of ETS. 2 6 ETS functional requirements 3 7 Reference mo
16、del . 5 8 Interfaces and protocols in support of ETS 7 9 Call flows 8 Q series Supplement 57 (01/2008) 1 Supplement 57 to ITU-T Q-series Recommendations Signalling requirements to support the emergency telecommunications service (ETS) in IP networks 1 Scope This supplement identifies the signalling
17、requirements to support preferential capabilities within IP networks for the emergency telecommunications service (ETS), which involves authority-to-authority communication. NOTE National, regional or local emergency and public safety services, where an individual from general public is seeking assi
18、stance (i.e., individual-to-authority communication), are outside the scope of this supplement. 2 References ITU-T E.106 Recommendation ITU-T E.106 (2003), International Emergency Preference Scheme (IEPS) for disaster relief operations. ITU-T E.107 Recommendation ITU-T E.107 (2007), Emergency Teleco
19、mmunications Service (ETS) and interconnection framework for national implementations of ETS. ITU-T Q.3030 Recommendation ITU-T Q.3030 (2008), Signalling architecture for the NGN service control plane. ITU-T Q-Sup.53 ITU-T Q-series Supplement 53 (2005), Signalling requirements to support the Interna
20、tional Emergency Preference Scheme (IEPS). ITU-T Y.2171 Recommendation ITU-T Y.2171 (2006), Admission control priority levels in Next Generation Networks. ITU-T Y.2701 Recommendation ITU-T Y.2701 (2007), Security requirements for NGN release 1. IETF RFC 4412 IETF RFC 4412 (2006), Communications Reso
21、urce Priority for the Session Initiation Protocol (SIP). 3 Definitions This supplement uses the definitions from ITU-T E.107. 4 Abbreviations and acronyms This supplement uses the following abbreviations and acronyms: AGC-FE Access Gateway Control Functional Entity AMG-FE Access Media Gateway Functi
22、onal Entity BGC-FE Breakout Gateway Control Functional Entity ETS Emergency Telecommunications Service FE Functional Entity GSC-FE General Services Control Functional Entity I-CSC-FE Interrogating Call Session Control Functional Entity 2 Q series Supplement 57 (01/2008) IBC-FE Interconnection Border
23、 Gateway Control Functional Entity IBG-FE Interconnection Border Gateway Functional Entity IP Internet Protocol ISDN Integrated Services Digital Network ISUP Integrated Services Digital Network User Part MGC-FE Media Gateway Control Functional Entity MRB-FE Media Resource Broker Functional Entity MR
24、C-FE Media Resource Control Functional Entity MRP-FE Media Resource Processing Functional Entity NSIW-FE Network Signalling Interworking Functional Entity NGN Next Generation Network P-CSC-FE Proxy Call Session Control Functional Entity PD-FE Policy Decision Functional Entity PIN Personal Identifica
25、tion Number PLMN Public Land Mobile Network PSTN Public Switched Telephone Network RTP Real Time Protocol S-CSC-FE Serving Call Session Control Functional Entity SAA-FE Service Authentication and Authorization Functional Entity SG-FE Signalling Gateway Functional Entity SIP Session Initiation Protoc
26、ol SL-FE Subscription Locator Functional Entity SUP-FE Service User Profile Functional Entity TDM Time Division Multiplex TLM-FE Transport Location Management Functional Entity TMG-FE Trunking Media Gateway Functional Entity UDP User Datagram Protocol USIW-FE User Signalling Interworking Functional
27、Entity All other relevant abbreviations are contained in the references listed in clause 2. 5 General aspects of ETS ETS is a national service that enables use of public telecommunications by authorized ETS users for disaster relief operations, security and emergency preparedness. It allows ETS user
28、s to have priority access to and priority use of the services offered by public networks. An ETS user is a user authorized to obtain priority telecommunications in national and/or international emergency situations. ETS significantly increases the ability of ETS users to initiate and complete their
29、communications (voice, data and video) via the PSTN, ISDN, PLMN and/or NGN during network failures or congestion. ETS utilizes the features, facilities and applications available in national public networks and service offerings. Implementation of ETS by definition is a national matter. Q series Sup
30、plement 57 (01/2008) 3 ITU-T E.107 provides a description of ETS and an interconnection framework for national implementations of ETS. 6 ETS functional requirements ETS implementations are likely to exhibit some of the following characteristics that have a bearing on signalling: a) An originating na
31、tional network may use various methods to identify a request for ETS communication: a special access code preceding the dialled called party number/identity; call origination from a specially marked line or access facility, or a uniquely identified user terminal; recognition of calls to a set of uni
32、que called party numbers or a range of numbers; special indicator or marking in the call/session establishment request; administrative actions to activate the service for all calls/sessions from a particular line or access facility for a period of time. b) As a national capability, ETS is specifical
33、ly designed to serve the telecommunications needs of authorized ETS users. How users, devices or user and device combinations are authenticated and authorized for ETS is a national matter. The calling partys authorization to initiate an ETS call, session or other communication must be authenticated.
34、 Authentication may be on a per-call/session basis, on a one-time (time-limited) authentication basis applicable to the calling partys current access, or on a subscription basis. If authentication is per call or session, the authentication process may involve an interactive exchange of authorization
35、 details that may include a personal identification number (PIN) or other authorization/identification code. Authorization information may be directly entered by the calling party, by the calling partys terminal, or by the network. ETS authentication and authorization may involve verifying the ident
36、ities and authorization of the calling user, user device or user and device combination. After the call/session request is authorized, the call/session is marked with ETS indicators and, optionally, the ETS Users priority level. c) An ETS call, session or communication is provided end-to-end priorit
37、y treatment beyond that offered to the general public. The priority treatment is applied during the call/session establishment phase, and should continue to be applied for the duration of the call, session or communication. The priority treatment consists of priority mechanisms and features applicab
38、le to various aspects (e.g., signalling, control, routing and media traffic) that are essential for the establishment and continuation of the communication. The process of providing end-to-end priority treatment begins with the ETS users invocation of ETS, and authentication and authorization of the
39、 users request by the service provider. End-to-end priority treatment includes: 1) signalling of ETS-related information; 2) priority treatment mechanisms; and 3) priority at interconnection between service provider networks and protocol interworking between different technology domains. These are b
40、riefly described below. Signalling: A number of network elements providing applications and transport functions (within circuit-switched networks and NGNs) can be involved in providing ETS. Therefore, there is a need to support signalling for the invocation, authentication and authorization of ETS.
41、Upon successful authentication and authorization, there is a need to signal ETS-related information (e.g., ETS authorization-related information, ETS indicators, and possibly priority level of the ETS user) among various network elements involved in providing priority treatment. The means for commun
42、icating ETS 4 Q series Supplement 57 (01/2008) indicators include specific addresses, fields within various protocols involved in providing ETS, and attributes within application programming interfaces. Priority treatment: Priority treatment should be applied to the routing, transport and processing
43、 of signalling messages associated with ETS, and to media and flows associated with ETS. Various mechanisms can be used to provide priority treatment. Priority treatment mechanisms can include priority call/session setup (e.g., high call/session admission control priority, priority queuing schemes f
44、or network resources), access to additional resources (e.g., via alternate routing), and exemption from restrictive network traffic management controls. Pre-emption in the public network (i.e., terminating any established communication to release resources to serve a new ETS communication request) i
45、s a national matter. Network interconnection and protocol interworking: ETS invocation, authentication, authorization, and the resulting call, session or communication can extend across multiple service provider networks. Therefore, the signalling of ETS indicators and the ETS priority treatment des
46、cribed above need to be extended across service provider network boundaries. Similarly, there is a need to provide interworking of ETS indicators (item 1) and the priority treatment (item 2) between different technology domains (e.g., between a circuit-switched network and an NGN), even within the s
47、ame service provider network. Interconnection and interworking apply to both the signalling and media. For example, a voice call originating in an IP domain may terminate on a PSTN telephone requiring interworking between SIP and ISUP at the signalling level and between RTP/UDP/IP packets and TDM tr
48、unks at the transport level. d) An ETS user should be able to communicate with any other available user. For example, any restrictions to call/session completion (e.g., call-barring) set by or for the called party should be overridden. e) Different priority levels may be assigned to ETS users for di
49、fferentiation among them for the purpose of providing priority treatment. For example, a call/session initiated by a user of higher priority may be serviced before a call/session of lower priority when calls/sessions are queued because of limited resources. A national government/administration decides whether user priority levels will be assigned to ETS users and, if assigned, how many levels will be used and the assignment criteria. As general guidance, the numerical user priority level values should be assigned in
