1、 International Telecommunication Union ITU-T H.248.76TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (09/2010) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Communication procedures Gateway control protocol: Filter group package and guidelines Recommendation ITU-
2、T H.248.76 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
3、.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 multimedia services
4、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 collaboration applications and
5、 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 BROADBAND, TRIPLE-PLAY
6、 AND ADVANCED 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 eve
7、nt 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 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T H.248.76 (09/2010) i Recommendation ITU-T H.248.76 Gateway control
8、protocol: Filter group package and guidelines Summary Recommendation ITU-T H.248.76 defines the filter group package. Using this package, the media gateway controller (MGC) can create and manage groups of filters, then apply those filter-groups to the media gateway (MG) terminations and streams. Whi
9、le the filter group package provides the framework for managing filters, it does not provide protocol elements for defining the filters concrete match conditions and actions. Instead, it relies on using elements from other packages, for example, the packages defined by Recommendation ITU-T H.248.43.
10、 History Edition Recommendation Approval Study Group 1.0 ITU-T H.248.76 2010-09-13 16 ii Rec. ITU-T H.248.76 (09/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICT
11、s). 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 telecommunications on a worldwide basis. The World Telecommunication
12、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 the procedure laid down in WTSA Resolution 1. In some areas of inform
13、ation 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 a telecommunication administration and a recognized operating agenc
14、y. 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 of these mandatory provisions are met. The words “shall“ or some
15、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 RIGHTS ITU draws attention to the possibility that the practice or im
16、plementation 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 development proc
17、ess. 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 may not represent the latest information and are therefore strongl
18、y 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 H.248.76 (09/2010) iii CONTENTS Page 1 Scope 1 2 References. 1 3 D
19、efinitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Filter Group package 2 6.1 Properties 3 6.2 Events . 4 6.3 Signals 4 6.4 Statistics 4 6.5 Error codes 4 6.6 Procedures 5 Bibliography. 9 Rec. ITU-T H.248.76 (09/20
20、10) 1 Recommendation ITU-T H.248.76 Gateway control protocol: Filter group package and guidelines 1 Scope This Recommendation defines the filter group package. Using this package, the media gateway controller (MGC) can create and manage groups of filters, then apply those filter-groups to the MGs te
21、rminations and streams. The package is especially useful when large groups of related filters are called for, as it allows the MGC to manipulate the individual filters without having to repeat them all in each ITU-T H.248 command. The filter group package provides protocol elements and procedures fo
22、r: Creating groups of filters. Adding and removing filters to and from an existing filter-group. Modifying an existing filter. Assigning multiple filter-groups to any of the MGs terminations or streams. Collecting statistics regarding filters and filter-groups. The filter group package does not, how
23、ever, provide any protocol elements covering a filters concrete match conditions or actions. Instead, the package should be combined with other packages that provide such elements, e.g., the packages defined by ITU-T H.248.43. 2 References The following ITU-T Recommendations and other references con
24、tain 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 therefore encouraged to investigate t
25、he 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 stand-alone document, the status of a
26、 Recommendation. ITU-T H.248.1 Recommendation ITU-T H.248.1 (2005), Gateway control protocol: Version 3, including its Amendment 1 (05/2008) and Amendment 2 (12/2009). ITU-T H.248.8 Recommendation ITU-T H.248.8 (2007), Gateway control protocol: Error code and service change reason description. ITU-T
27、 H.248.43 Recommendation ITU-T H.248.43 (2008), Gateway control protocol: Packages for gate management and gate control. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following term defined elsewhere: 3.1.1 filter ITU-T H.248.43: In general: A set of terms and/or criteria us
28、ed for the purpose of separating or categorizing. This is accomplished via single- or multi-field matching of traffic header and/or payload data. “Filters“ are often manipulated and used in network operation and policy. 2 Rec. ITU-T H.248.76 (09/2010) In an ITU-T H.248 framework: Filters specify the
29、 criteria for matching a pattern to distinguish separable classes of traffic. Filters are defined on the basis of H.248 properties, which determine the filters condition and actions. Typically a filter includes a single action element indicating either an “accept“ or “reject“ action, with or without
30、 statistics recording. NOTE 1 The definition is based on b-IETF RFC 3198 and b-IETF RFC 3060. NOTE 2 This filter definition implies the concept of filter actions as well as filter conditions. 3.2 Terms defined in this Recommendation This Recommendation uses the following terms: 3.2.1 filter-group co
31、ntext: An ITU-T H.248 context that defines a group of filters. This filter-group can then be referenced by other terminations or streams. 3.2.2 filter-group termination: A termination belonging to a filter-group context. Such a termination defines one filter out of the complete group. 4 Abbreviation
32、s and acronyms This Recommendation uses the following abbreviations and acronyms: MG Media Gateway MGC Media Gateway Controller 5 Conventions The names of ITU-T H.248 descriptors always have a capitalized first letter, for example, Streams and Local Descriptor. The names of ITU-T H.248 properties, e
33、vents, signals, statistics and parameters appear in italics, for example ReserveValue. All error codes appearing in this Recommendation are described in ITU-T H.248.8. 6 Filter Group package Package Name: Filter Group Package ID: filtgrp (0x0103) Description: This package allows the MGC to indicate
34、that a context is being used for defining a group of filters. That filter-group can then be applied to other terminations or streams, e.g., a termination representing a physical interface of the MG. This method for describing filter-groups is useful when a large number of filters are needed for a pa
35、rticular filter-group. It allows the creation, modification and deletion of individual filters without the need to repeat all filters in a single command Version: 1 Extends: None Rec. ITU-T H.248.76 (09/2010) 3 6.1 Properties 6.1.1 Filtering Context Property Name: Filtering Context Property ID: fc (
36、0x0001) Description: This context level property indicates that the context is being used to define a group of filters (i.e., the context is a filter-group context). Such a context may only contain ephemeral terminations. The setting of the property is valid for the whole lifetime of the context. Ty
37、pe: Enumeration Possible values: “FILT“ (0x0001): Filter-Group Context Default: “FILT“ (0x0001) Defined in: ContextAttribute Characteristics: Read/Write 6.1.2 Filter Group Identifier Property Name: Filter Group Identifier Property ID: fgid (0x0002) Description: This property may only be used at the
38、ContextAttribute level in a filter-group context. When used at that level, the property defines the identifier for the filter-group. Only one value shall be assigned, and that value must be unique across the complete MG (or virtual MG). When used at the TerminationState level, this property indicate
39、s the list of filter-groups that shall be applied to the termination. As such, it shall not be used on terminations belonging to a filter-group context. When used at the stream (i.e., LocalControl) level, this property indicates the list of filter-groups that shall be applied to the stream. As such,
40、 it shall not be used on terminations belonging to a filter-group context. Type: Sub-list of String Possible values: Any If no filter-groups are applied to a termination or stream, the property shall include a single empty string. The empty string identifier shall not be assigned to any filter-group
41、 context. Default: A single empty string Defined in: Local Control, TerminationState or ContextAttribute Characteristics: Read/Write 6.1.3 Relative Filter Order Property Name: Relative Filter Order Property ID: rfo (0x0003) Description: The relative position of the filter defined by the filter-group
42、 termination holding this property, compared to the filters of the other terminations within the filter-group context. The filter defined by the termination with the lowest filtgrp/rfo number shall be executed first; the filter defined by the termination 4 Rec. ITU-T H.248.76 (09/2010) with the next
43、-lowest filtgrp/rfo shall be executed second, etc. Terminations may not be assigned with identical filtgrp/rfo values within the same context. Type: Unsigned Integer Possible values: 1 and up Default: None Defined in: TerminationState Characteristics: Read/Write 6.2 Events None. 6.3 Signals None. 6.
44、4 Statistics None. 6.5 Error codes 6.5.1 Element not allowed in a filter-group context Error Code #: 481 Name: Element not allowed in a filter-group context Definition: A filter-group termination may only contain elements (properties/signals/events and statistics) defined by ITU-T H.248.43, and/or e
45、lements defined by other Recommendations that are related to packet filtering, and/or elements declared by other Recommendations as being valid for use in a filter-group context. A command that would result in other elements being used in such a termination shall be rejected using this error code. E
46、rror Text in the Error Descriptor: Comment: 6.5.2 Unknown filter-group Error Code #: 482 Name: Unknown filter-group Definition: The filter-group referenced is invalid or unknown. Therefore, the command is disregarded. Error Text in the ErrorDescriptor: Comment: Rec. ITU-T H.248.76 (09/2010) 5 6.6 Pr
47、ocedures 6.6.1 General The filter group package allows the MGC to gather a collection of filters into a single filter-group. The group is represented using a filter-group context, where each of the contexts terminations describes a single filter. The conditions and actions comprising each filter are
48、, in turn, encoded using the properties and statistics of the various packages dealing with gate management and filtering, such as those described in ITU-T H.248.43. The MGC can thus manage the filters of a filter-group by adding, modifying or subtracting individual terminations. Properties related
49、to the individual filters shall not be added at the ContextAttribute level. NOTE A filters conditions and actions can be defined using elements outside of ITU-T H.248.43; however, such filters are for further study. It is expected that Recommendations defining such elements will have a statement of applicability with regard to the support of the filter group package. Each filter-group context has a unique identifier, given by a ContextAttribute level Filter Group Identifier (filtgrp/fgid) pro
