1、 International Telecommunication Union ITU-T J.261TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (10/2009) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS IPCablecom Framework for implementing preferential telecommunications in IPCablecom and IP
2、Cablecom2 networks Recommendation ITU-T J.261 Rec. ITU-T J.261 (10/2009) i Recommendation ITU-T J.261 Framework for implementing preferential telecommunications in IPCablecom and IPCablecom2 networks Summary Recommendation ITU-T J.261 provides a framework for implementing preferential capabilities i
3、n IPCablecom and IPCablecom2 networks. The approach of this Recommendation is to define a framework for capabilities that can be utilized to meet the requirements in Recommendation ITU-T J.260 and forms the basis for detailed IPCablecom and IPCablecom2 Recommendations in support of preferential tele
4、communications. Source Recommendation ITU-T J.261 was approved on 30 October 2009 by ITU-T Study Group 9 (2009-2012) under the WTSA Resolution 1 procedure. ii Rec. ITU-T J.261 (10/2009) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of
5、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 on them with a view to standardizing te
6、lecommunications 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 th
7、e 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 used for conciseness to indicate both
8、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 the Recommendation is achieved when all
9、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 of any party. INTELLECTUAL PROPERTY RIGH
10、TS 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
11、 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, implementers are cautioned that this m
12、ay 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 written permission of ITU. Rec. ITU-T J
13、.261 (10/2009) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined here . 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 Common framework for priority 3 7 Common framework for authentication 5 7.1 User credentials-based authentication 5 7.2
14、 Equipment-based authentication 5 7.3 Basic authentication mechanisms . 5 7.4 Credentials management mechanisms 6 8 Authentication and priority in IPCablecom networks 7 8.1 Authentication in IPCablecom networks 7 8.2 Priority in IPCablecom networks . 7 9 Authentication and priority in IPCablecom2 ne
15、tworks 7 9.1 Authentication in IPCablecom2 networks 7 9.2 Priority in IPCablecom2 networks . 8 Bibliography. 10 iv Rec. ITU-T J.261 (10/2009) Introduction Emergency/disaster telecommunications for authorized users plays a vital role in the health, safety and welfare of people in all countries. The c
16、ommon thread to facilitate emergency/disaster operations is the utility of assured capabilities for user-friendly preferential telecommunication services that may be realized by technical solutions and/or administrative policy. The capabilities of IPCablecom and IPCablecom2 cable infrastructures off
17、er an important resource for assured preferential telecommunication services. The essential aspects of preferential telecommunication over cable networks that this framework Recommendation addresses are grouped into two prime areas: authentication and priority. These two areas are the vital network
18、features needed to obtain the resources of cable networks when preferential treatment is required. Other areas such as policy, traffic engineering, alternate routing, provisioning for restorability, etc., are either out of scope or not addressed in this version. The evolving nature of telecommunicat
19、ion networks in general, and of cable networks in particular, lends itself to a phased approach for the support of preferential treatment. A phased approach needs to consider the evolution of IPCablecom Recommendations: the initial suite of IPCablecom Recommendations, the IPCablecom Recommendations
20、as revised in 2005, and the IPCablecom2 suite of Recommendations. Rec. ITU-T J.261 (10/2009) 1 Recommendation ITU-T J.261 Framework for implementing preferential telecommunications in IPCablecom and IPCablecom2 networks 1 Scope The objective of this Recommendation is to provide a framework for the i
21、mplementation of preferential telecommunications services within cable networks as described in ITU-T J.160 and ITU-T J.360. This framework is one of the series of Recommendations addressing these services. The key aspects of preferential telecommunications services addressed in this framework are p
22、riority and authentication. The architectural differences in the two key aspects are addressed in terms of the logical functional entities defined in ITU-T J.160 and ITU-T J.360, respectively. Although this version of the framework addresses the two key aspects, namely, priority and authentication,
23、necessary to support preferential treatment in telecommunications services, other aspects such as policy, traffic engineering, alternate routing, provisioning, etc., are either out of scope or left for future study. As an example, future versions are expected to address provisioning of preferential
24、services for specific users and/or devices (media terminal adapters) at specific locations. 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 ed
25、itions 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 va
26、lid 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 J.160 Recommendation ITU-T J.160 (2005), Architectural framework for the delivery of time-critical services over
27、 cable television networks using cable modems. ITU-T J.163 Recommendation ITU-T J.163 (2007), Dynamic quality of service for the provision of real-time services over cable television networks using cable modems. ITU-T J.170 Recommendation ITU-T J.170 (2005), IPCablecom security specification. ITU-T
28、J.179 Recommendation ITU-T J.179 (2005), IPCablecom support for multimedia. ITU-T J.260 Recommendation ITU-T J.260 (2005), Requirements for preferential telecommunications over IPCablecom networks. ITU-T J.360 Recommendation ITU-T J.360 (2006), IPCablecom2 architecture framework. ITU-T J.368 Recomme
29、ndation ITU-T J.368 (2008), IPCablecom2 quality of service specification. IETF RFC 3261 IETF RFC 3261 (2002), SIP: Session Initiation Protocol. IETF RFC 4412 IETF RFC 4412 (2006), Communications Resource Priority for the Session Initiation Protocol (SIP). 2 Rec. ITU-T J.261 (10/2009) 3 Definitions 3
30、.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 assured capabilities ITU-T J.260: Capabilities providing high confidence or certainty that critical telecommunications are available and perform reliably. 3.1.2 authentication ITU-T J.260: The act or met
31、hod used to verify a claimed identity. 3.1.3 authorization ITU-T J.260: The act of determining if a particular privilege, such as access to telecommunications resources, can be granted to the presenter of a particular credential. 3.1.4 cable modem ITU-T J.160: A cable modem is a layer two terminatio
32、n device that terminates the customer end of the DOCSIS connection. 3.1.5 emergency situation ITU-T J.260: A situation, of serious nature, that develops suddenly and unexpectedly. Extensive immediate important efforts, facilitated by telecommunications, may be required to restore a state of normalit
33、y to avoid further risk to people or property. If this situation escalates, it may become a crisis and/or disaster. 3.1.6 international emergency situation ITU-T J.260: An emergency situation, across international boundaries, that affects more than one country. 3.1.7 IPCablecom ITU-T J.160: An ITU-T
34、 project that includes an architecture and a series of Recommendations that enable the delivery of real-time services over the cable television networks using cable modems. 3.1.8 label ITU-T J.260: An identifier occurring within or attached to data elements. In the context of preferential telecommun
35、ications it is an indication of priority. This identifier can be used as a mapping mechanism between different network priority levels. 3.1.9 managed IP network ITU-T J.160: An IP network, managed by a single entity for the purpose of transporting IPCablecom signalling and media packets. 3.1.10 pref
36、erential ITU-T J.260: A capability offering advantage over regular capabilities. 3.1.11 priority treatment capabilities ITU-T J.260: Capabilities that provide premium access to, and/or use of telecommunications network resources. 3.1.12 subscriber ITU-T J.360: An entity (comprising one or more users
37、) that is engaged in a subscription with a service provider. 3.1.13 user agent (UA) ITU-T J.360: A SIP user agent as defined by IETF RFC 3261. 3.2 Terms defined in this Recommendation This Recommendation defines the following term: 3.2.1 user equipment: Any device used directly by an end user to com
38、municate. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: AKA Authentication and Key Agreement ATM Automatic Teller Machine AVP Attribute Value Pair CM Cable Modem CMS Call Management Server Rec. ITU-T J.261 (10/2009) 3 CMTS Cable Modem Termination Sys
39、tem DQoS Dynamic Quality of Service E-DVA Embedded Digital Voice Adapter E-MTA Embedded Media Terminal Adapter IPSec Internet Protocol Security KDC Key Distribution Centre MGC Media Gateway Controller MTA Media Terminal Adapter P-CSCF Proxy Call Session Control Function PIN Personal Identification N
40、umber PKI Public Key Infrastructure PKINIT Public Key Cryptography for Initial Authentication PSTN Public Switched Telephone Network QoS Quality of Service RTP Real-time Transport Protocol SIP Session Initiation Protocol TGT Ticket Granting Ticket TLS Transport Layer Security UE User Equipment 5 Con
41、ventions None. 6 Common framework for priority ITU-T J.260 lists a number of requirements to assure priority treatment in IPCablecom and IPCablecom2 networks. Even though architectural differences exist between IPCablecom described in ITU-T J.160 and IPCablecom2 in ITU-T J.360, this clause discusses
42、 the framework that is applicable for both networks. There are three aspects to consider when addressing priority treatment for preferential telecommunications services. These are classification or labelling of the session or call as requiring priority treatment, signalling for priority and the mech
43、anisms to support the requested priority. The selection of mechanisms and policies, along with their respective implementations, are outside the scope of this Recommendation. Table 1 categorizes the requirements according to these three aspects: classification, signalling and mechanisms. Some of the
44、 requirements are categorized to have more than one aspect because the priority classification of the call is to be maintained and the actual mechanisms to preserve the classification may vary. 4 Rec. ITU-T J.261 (10/2009) Table 1 Mapping requirements to priority aspects ITU-T J.260 requirement Cate
45、gory Priority access to the IPCablecom and IPCablecom2 networks (1a) Classification Call activation and call features (1b) Signalling Allocating network resources (1c) Mechanisms Priority given to labelled calls at gateways (1d) Signalling and mechanisms Assigning labels at call origination (2) Clas
46、sification Priority given to labelled calls within IPCablecom and IPCablecom2 networks (3) Mechanisms Map the labels used from/to the cable network to/from the connecting network gateway device (4 and 5) Mechanisms Preserve the priority label across the cable network (6) Signalling and mechanisms Pr
47、iority call in transit through cable network is treated according to cable network capabilities (7) Classification and mechanisms Number of levels for priority: minimum 1 and additional levels based on national options (8) Classification Priority treatment given by cable network to calls with priori
48、ty label from a trusted network (9) Mechanisms Prioritization means obtaining a higher probability for completing a call/session. In other words, once the traffic is identified to be for a preferential telecommunications service, the policies need to provide a higher probability of success relative
49、to call admission, routing and delivery of traffic. This capability should exist on the access link and should also be propagated throughout all relevant network entities such as call management servers (CMSs) and media gateway controllers (MGCs) or the entities in the session initiation protocol (SIP) infrastructure. Even though priority enabling mechanisms and assignment of QoS are not the same, in IPCablecom, DQoS session classes can be used to assign priority treatment to a session. One of the requirements to
