1、 International Telecommunication Union ITU-T H.248.63TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2009) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Communication procedures Gateway control protocol: Resource management packages Recommendation ITU-T H.248
2、.63 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 procedures H.240H.2
3、59 Coding 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 multimedia services H.360H
4、.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 collaboration applications and servi
5、ces 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.559Mobile multimedia collaboration inter-working procedures H.560H.569 BROADBAND, TRIPLE-PLAY AND AD
6、VANCED MULTIMEDIA SERVICES Broadband multimedia services over VDSL H.610H.619 Advanced multimedia services and applications H.620H.629 IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV General aspects H.700H.719 IPTV terminal devices H.720H.729 IPTV middleware H.730H.739 IPTV application event hand
7、ling H.740H.749 IPTV metadata H.750H.759 IPTV multimedia application frameworks H.760H.769 IPTV service discovery up to consumption H.770H.779 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T H.248.63 (03/2009) i Recommendation ITU-T H.248.63 Gateway control protoco
8、l: Resource management packages Summary Recommendation ITU-T H.248.63 contains packages that allow a media gateway controller (MGC) and media gateway (MG) to work together to allow a MG to manage its resources in the most efficient manner possible. It allows the MGC to indicate which resources may b
9、e used in the Context and whether the use of certain resources will change or not for the life of the Termination/Stream. The MG can then use this information to optimize the allocation and use of resources. Source Recommendation ITU-T H.248.63 was approved on 16 March 2009 by ITU-T Study Group 16 (
10、2009-2012) under Recommendation ITU-T A.8 procedures. ii Rec. ITU-T H.248.63 (03/2009) 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 St
11、andardization 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 telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA),
12、 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 procedure laid down in WTSA Resolution 1. In some areas of information technology which fall with
13、in 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 telecommunication administration and a recognized operating agency. Compliance with this Recommen
14、dation 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 these mandatory provisions are met. The words “shall“ or some other obligatory language such as
15、“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 ITU draws attention to the possibility that the practice or implementation of this Recommendatio
16、n 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 development process. As of the date of approval of
17、 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 not represent the latest information and are therefore strongly urged to consult the TSB patent
18、database at http:/www.itu.int/ITU-T/ipr/. ITU 2009 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 H.248.63 (03/2009) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 3.1 Terms defined els
19、ewhere 2 3.2 Terms defined in this Recommendation. 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Resource management interactions 2 6.1 Interaction with related H.248 Recommendations . 3 7 Resource management rules package . 4 7.1 Properties 5 7.2 Events . 5 7.3 Signals 6 7.4 Statistics 6 7.5 E
20、rror codes 6 7.6 Procedures 6 8 Resource management configuration package . 7 8.1 Properties 7 8.2 Events . 8 8.3 Signals 8 8.4 Statistics 8 8.5 Error codes 8 8.6 Procedures 8 9 Abstract resource management package. 9 9.1 Properties 9 9.2 Events . 10 9.3 Signals 10 9.4 Statistics 10 9.5 Error Codes.
21、 10 9.6 Procedures 10 Bibliography. 12 Rec. ITU-T H.248.63 (03/2009) 1 Recommendation ITU-T H.248.63 Gateway control protocol: Resource management packages 1 Scope This Recommendation contains packages that allow a media gateway controller (MGC) and a media gateway (MG) to work together to allow the
22、 MG to manage its resources in the most efficient manner possible. Three approaches are defined: rules-based, configuration, and abstract. In the rules-based approach, the MG expects the MGC to behave in a particular manner in order to manage resources. For example, the MG may expect that, for optim
23、al resource allocation, once a stream is assigned to a particular media (e.g., audio), it will not change it to another media (e.g., video). In the configuration approach, the MGC indicates the expected characteristics of the Context in terms of the actual resources required. This could be a number
24、of a particular type of Termination. For example, the MGC could indicate that for a particular Context, it may have up to five receive-only Terminations. An “abstract“ approach is also provided, whereby the MGC indicates a specific resource management requirement via a single codepoint which then re
25、lates directly to a particular H.248 configuration. For example, the MGC could indicate “conference listener“ and this would then map directly to a send-only Termination configuration and to a particular type of audio codec. The description of MG internal resource structures is out of scope of this
26、Recommendation. This Recommendation assumes that the MGC is responsible for determining for how long the resources are reserved, and thus is responsible for requesting and clearing the resources. This is in keeping with the H.248 LocalControl descriptor ReserveGroup/ReserveValue functionality. 2 Ref
27、erences 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 editions indicated were valid. All Recommendations and other references are subject to revision; us
28、ers 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 valid ITU-T Recommendations is regularly published. The reference to a document within this Recomme
29、ndation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T H.248.1 Recommendation ITU-T H.248.1 (2005), Gateway Control Protocol: Version 3. ITU-T H.248.19 Recommendation ITU-T H.248.19 (2004), Gateway control protocol: Decomposed multipoint control unit, audio, video
30、 and data conferencing packages. ITU-T H.248.32 Recommendation ITU-T H.248.32 (2005), Gateway control protocol: Detailed congestion reporting package. ITU-T H.248.39 Recommendation ITU-T H.248.39 (2006), Gateway control protocol: H.248 SDP parameter identification and wildcarding. ITU-T H.248.46 Rec
31、ommendation ITU-T H.248.46 (2007), Gateway control protocol: Connection capability control package. 2 Rec. ITU-T H.248.63 (03/2009) 3 Definitions 3.1 Terms defined elsewhere None. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 MG resource: This is a g
32、eneric term that describes physical or logical entities in a MG used by the MG to perform a certain function. These resources could be but are not limited to processor resources, memory resources, system resources, and digital signal processor resources. 3.2.2 resource management rule: This is a gen
33、eric term to describe a set of procedures/H.248 actions that a MG expects a MGC to adopt in order to optimize resources. The terms “rule“ or “rules“ are used in this Recommendation to mean “Resource Management Rule“. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations a
34、nd acronyms: ABNF Augmented Backus-Naur Form AMR Adaptive Multi-Rate ASN.1 Abstract Syntax Notation One BHCoA Busy Hour Context Attempts Cxt Context MG Media Gateway MGC Media Gateway Controller Tid Termination Identifier 5 Conventions None. 6 Resource management interactions A MG only has a finite
35、set of resources that may be committed in order to satisfy requests from its MGC. In some instances, the use of resource management mechanisms provides a means for the MG to optimize how it assigns and uses resources. How the MG actually assigns physical resources at the time of the request may resu
36、lt in poor performance as resources are being held without being used. This may limit the number of MGC requests that can be satisfied. In some usage scenarios, the resource availability may be reduced if implementations reserve resources in advance of their use in order to ensure they are available
37、 for a given call. This would particularly occur where such resources are dimensioned based on a pooling or timeshare concept. Therefore, the balance between reservation and availability should also be considered. As such, the use of the packages in this Recommendation does not negate the need for c
38、orrect network dimensioning. When dimensioning a network, the type of calls and their percentage of the overall traffic need to be taken into account. However, the proper usage of the packages in this Recommendation leads to better resource availability allowing certain services to be more reliable.
39、 In packages using a rules-based approach (i.e., Resource Management Rules package, rmr) in conjunction with network dimensioning, the MG can optimize its resource allocation/usage according to the specified rule. Rec. ITU-T H.248.63 (03/2009) 3 In packages using a configuration approach (i.e., Reso
40、urce Management Configuration package, rmc), the MG receives an indication of what resources are likely to be used for a particular Context. When combined with dimensioning, it allows the MG to optimize the resource availability pools. The configuration approach can be applied at any time during cal
41、l establishment. Thus, the configuration applied may be based on a particular service. Indicating resources at call establishment is unlikely to have a detrimental effect on available resources because, if there are any unused resources, they may be cleared when the call/session reaches a steady sta
42、te. In cases where the steady state may be determined and the resources may be freed, if used correctly, the packages will have little detrimental effect on pooling or dimensioning, and will enhance resource availability for a particular connection. In other cases, the use of the packages needs to b
43、e considered against potential pooling or dimensioning issues as it may lead to an increase in the utilization of the resources. In packages using an abstraction approach (i.e., Abstract Resource Management package, arm), an indication is used to describe a general set of behaviour. This is used to
44、allow the MG to optimize resources based on a certain service need. Given that ITU-T H.248.1 already permits a level of detachment from the MGC call level service description and of the implementation of resources in the MG, the abstraction codepoints are accompanied by a “Resource mapping Descripti
45、on“ and “Procedures“ to ensure that the usage is clear. The packages in this Recommendation assume the MG uses the information in the packages to optimize its resource allocation and processing. It is assumed that the MG will only commit physical resources when descriptors of the H.248 commands indi
46、cate so. As a result, Context priority handling procedures should not be modified as a result of the packages in this Recommendation. 6.1 Interaction with related H.248 Recommendations 6.1.1 Core gateway control protocol (H.248.1) The ITU-T H.248.1 protocol has resource reservation capabilities defi
47、ned in its core behaviour. The “Reserve Value“ and “Reserve Group“ properties of the LocalControl Descriptor allow a MGC to request a MG to reserve resources for all alternatives specified in the Local and/or Remote Descriptors for which it currently has resources available. This allows an MGC durin
48、g call establishment to reserve resources in order to negotiate the media properties and then later remove the unnecessary resources once the call reaches steady state. Likewise, the Resource Management Configuration (rmc) package allows the MGC to reserve resources (in addition to Local and Remote
49、resources) which may then be later released if they are unnecessary when the call reaches steady state. 6.1.2 Decomposed multipoint control unit, audio, video and data conferencing (H.248.19) ITU-T H.248.19 currently describes the interface between the MGC and the MG in a decomposed multipoint control unit which largely provides conferencing services. There is currently no discussion in ITU-T H.248.19 regarding resource management. However, there exists scope for optimizing resource usage for conferencing scenarios. Conference resources can be
