1、 International Telecommunication Union ITU-T H.248.29TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2013) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Communication procedures Gateway control protocol: International CAS compelled register signalling package
2、s Recommendation ITU-T H.248.29 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 Commu
3、nication procedures H.240H.259Coding of moving video H.260H.279 Related systems aspects H.280H.299 Systems and terminal equipment for audiovisual services H.300H.349 Directory services architecture for audiovisual and multimedia services H.350H.359 Quality of service architecture for audiovisual and
4、 multimedia services H.360H.369 Supplementary services for multimedia H.450H.499 MOBILITY AND COLLABORATION PROCEDURES Overview of Mobility and Collaboration, definitions, protocols and procedures H.500H.509 Mobility for H-Series multimedia systems and services H.510H.519 Mobile multimedia collabora
5、tion applications and services H.520H.529 Security for mobile multimedia systems and services H.530H.539 Security for mobile multimedia collaboration applications and services H.540H.549 Mobility interworking procedures H.550H.559 Mobile multimedia collaboration inter-working procedures H.560H.569 B
6、ROADBAND, TRIPLE-PLAY AND ADVANCED MULTIMEDIA SERVICES Broadband multimedia services over VDSL H.610H.619 Advanced multimedia services and applications H.620H.629 Ubiquitous sensor network applications and Internet of Things H.640H.649 IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV General aspec
7、ts H.700H.719 IPTV terminal devices H.720H.729 IPTV middleware H.730H.739 IPTV application event handling H.740H.749 IPTV metadata H.750H.759 IPTV multimedia application frameworks H.760H.769 IPTV service discovery up to consumption H.770H.779 Digital Signage H.780H.789 For further details, please r
8、efer to the list of ITU-T Recommendations. Rec. ITU-T H.248.29 (03/2013) i Recommendation ITU-T H.248.29 Gateway control protocol: International CAS compelled register signalling packages Summary The packages in Recommendation ITU-T H.248.29 provide ITU-T H.248 support for channel associated signall
9、ing (CAS) compelled register signalling. This can be used for R2, although the packages are generic so that they can also be used for other non-R2 compelled schemes. This Recommendation proposes methods to support: standard en bloc compelling; overlap compelling; the ability to enable end-to-end com
10、pelled signalling. This Recommendation provides only the capabilities of compelled register signalling and it is expected that a system would need to implement the bcas, icas and casblk packages for the line signalling components of any CAS protocol. Three packages are defined in Annex A: icasc whic
11、h provides standard en bloc compelling; icasco which extends icasc and provides overlap compelling in addition to en bloc; icasce which extends icasco and provides the ability to enable end-to-end signalling in addition to en bloc and overlap. Annex B defines an alternative package for support of th
12、ese functions, called icascgen. This package defines a generic register signalling, which may be used for national variants of Signalling System R2. This kind of interregister signalling is a compelled multifrequency code system. The package is suitable for ITU-T Signalling System R2, although it is
13、 defined in a generic way. Thus it can also be used exclusively, or in addition to the packages defined in Annex A. The proposed package comprises following compelled address transfer modes: generic standard en bloc compelling; and overlap procedures. NOTE The ability to enable end-to-end compelled
14、signalling utilizing Annex B is for further study. Annex B introduces the concepts of Detection Events Map and Generation Signals Map, which are very similar to ITU-T H.248 Digit Map usage. This revision incorporates a new parameter to indicate whether the Generic Digit information Event is generate
15、d in the event of an unsuccessful events map match. History Edition Recommendation Approval Study Group 1.0 ITU-T H.248.29 2005-01-08 16 1.1 ITU-T H.248.29 (2005) Cor. 1 2007-08-29 16 2.0 ITU-T H.248.29 2013-03-16 16 ii Rec. ITU-T H.248.29 (03/2013) FOREWORD The International Telecommunication Union
16、 (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-T is responsible for studying technical, operating and tariff questions and
17、 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 study by the ITU-T study groups which, in turn, produce Recommendations on thes
18、e 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 collaborative basis with ISO and IEC. NOTE In this Recommendation, the expre
19、ssion “Administration“ is used for conciseness to indicate both 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 applicabi
20、lity) and compliance with the Recommendation 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. The use of such words does not suggest that compliance with the R
21、ecommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS 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 applicabilit
22、y of claimed Intellectual Property Rights, whether asserted by ITU 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 th
23、is Recommendation. 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 2013 All rights reserved. No part of this publication may be reproduced, by any means wha
24、tsoever, without the prior written permission of ITU. Rec. ITU-T H.248.29 (03/2013) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 4 Abbreviations and acronyms 2 5 ITU-T H.248 package approaches for compelled CAS 3 5.1 System operation modes . 3 5.2 Reasons and criteria 3 5.3 M
25、otivation for two package approaches . 3 Annex A International CAS compelled register signalling packages . 5 A.1 International CAS Compelled Package 5 A.2 International CAS Compelled with Overlap Package 20 A.3 International CAS Compelled with End-to-End Package 26 Annex B Generic CAS compelled reg
26、ister signalling package 31 B.1 Generic CAS Compelled Register Signalling Package 31 B.2 ABNF encoding 49 Appendix I Timing aspects . 50 Appendix II Survey of ITU-T H.248 packages for CAS 52 Bibliography. 54 Rec. ITU-T H.248.29 (03/2013) 1 Recommendation ITU-T H.248.29 Gateway control protocol: Inte
27、rnational CAS compelled register signalling packages 1 Scope These packages are intended for use in analogue (one-way operation) or digital transmission systems (one-way or both-ways operations). The MGC should be unaware of the transmission details at the physical layer. The MG is therefore assumed
28、 to be provisioned with the actual signalling frequencies for interregister signalling (for example 2-out-of-n inband multifrequency code with forward and backward compelled signalling for R2) along with their properties such as amplitude, tone duration, cadence, etc. and also their logical signific
29、ance. Any timers that dictate the interregister compelling actions are also assumed to be provisioned in the MG. NOTE Annex B specifies additional termination properties allowing the definition of some SSR2 timers. Support for any of these packages is optional. 2 References The following ITU-T Recom
30、mendations 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 th
31、erefore 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 st
32、and-alone document, the status of a Recommendation. ITU-T H.248.1 Recommendation ITU-T H.248.1 (2013), Gateway control protocol: Version 3. ITU-T H.248.16 Recommendation ITU-T H.248.16 (2013), Gateway control protocol: Enhanced digit collection packages and procedures. ITU-T H.248.25 Recommendation
33、ITU-T H.248.25 (2013), Gateway control protocol: Basic CAS packages. ITU-T H.248.28 Recommendation ITU-T H.248.28 (2007), Gateway control protocol: International CAS packages. ITU-T Q.400 Recommendation ITU-T Q.400-Q.490 (1988), Specifications of Signalling System R2. ITU-T Q-Sup.7 ITU-T Q-series Re
34、commendations Supplement 7 (1988), Semi-compelled and non-compelled multifrequency interregister signalling for national satellite applications based on System R2 interregister signalling. 3 Definitions This Recommendation defines the following terms: 3.1 backward signal: A signal, used for the esta
35、blishment, release or other control of a connection, sent in the opposite direction to call set-up. 3.2 compelled signalling: A signalling method in which the signal to be transmitted is applied continuously until acknowledged or until a timeout occurs. Upon recognition of the initial signal, the ac
36、knowledgement signal is applied continuously until the cessation of the initial signal or until a timeout occurs. The cessation of the acknowledgement signal may provoke the beginning of the 2 Rec. ITU-T H.248.29 (03/2013) next subsequent compelled cycle. In addition to the acknowledgement, the ackn
37、owledgement signal may carry other signalling information (e.g., concerning the next cycle). 3.3 en bloc signalling: A signalling method in which the address digits are assembled into one block for onward transmission, the block containing all of the address information necessary to route the call t
38、o its destination. 3.4 end-to-end signalling: A signalling method in which signals are transmitted from one end of a multi-link connection to the other end where processing of these signals is required. 3.5 forward signal: A signal, used for the establishment, release or other control of a connectio
39、n sent in the same direction as call set-up. 3.6 interregister signalling: Signalling System R2: Interregister signals are of the multifrequency type using a 2-out-of-6 in-band code in both directions. The multifrequency combinations are sent and received by multifrequency signalling equipment which
40、 is assumed to be associated with the registers used to control the switching equipment at both ends of the inter-exchange link. 3.7 KP (start-of-pulsing) signal (sent in the forward direction): This register signal is sent subsequent to the recognition of a start-dialling signal and is used to prep
41、are the incoming multifrequency register for the receipt of subsequent interregister signals. 3.8 line signalling: A signalling method in which signals are transmitted between equipment which terminate and continuously monitor part or all of the traffic circuit. 3.9 overlap address signalling: A sig
42、nalling method in which the onward transmission of address signals from a switching centre may commence before the reception of all the address signals over the preceding link has been completed. 3.10 register: The apparatus, in an automatic system, which receives the dialled impulses and controls t
43、he subsequent switching operations. 3.11 register function: The functions of receiving, storing, analysing and possibly translating and transmitting address information and other information for the purpose of controlling the setting-up of a call. 3.12 register signalling: Signalling System R1: Link
44、-by-link multifrequency (MF) in-band pulse signalling is used for the transmission of address information. The signalling frequencies are 700 Hz to 1700 Hz, in 200 Hz steps, and combinations of two, and two only, determine the signal. The address information is preceded by a KP signal (start-of-puls
45、ing) and terminated by an ST signal (end-of-pulsing). Either en bloc, en bloc overlap or overlap sending may apply. This register signalling arrangement is used extensively with other in-band and out-of-band line signalling systems. 3.13 ST (end-of-pulsing) signal (sent in the forward direction): Th
46、is register signal is sent to indicate that there are no more address signals to follow. The signal is always sent in semi-automatic as well as automatic working. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: CAS Channel Associated Signalling IC Inco
47、ming MC Multifrequency Combination MF Multifrequency MG Media Gateway Rec. ITU-T H.248.29 (03/2013) 3 MGC Media Gateway Controller NGN Next Generation Network OG Outgoing SSR2 Signalling System R2 5 ITU-T H.248 package approaches for compelled CAS This Recommendation takes into account that there ar
48、e various NGN evolution scenarios for legacy compelled CAS equipment. Thus, it supports different modes of operation. 5.1 System operation modes This Recommendation defines two operation modes of the ITU-T H.248 interface for support of international compelled CAS register signalling systems (see Ap
49、pendix II for a complete CAS system overview). The first design is more “MG centric“ and covered in Annex A. The second approach in Annex B may be correspondingly called “MGC centric“. The background is a slightly different functional partitioning concept with respect to control and CAS signalling handling. “MGC centric“ means that the full handling is more or less located in the ITU-T H.248 media gateway controller. In the “MG centric“ approach, the ITU-T H.248 media gateway provides local handling, for
