1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU H.248 Annex M2 (07/2001) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Infrastructure of audiovisual services - Communication procedu res Gateway control protocol Annex M2: Media Gateway resource congestion ha
2、ndling package ITU-T Recommendation H.248 - Annex M2 (Formerly CCITT Recommendation) - INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU H.248 Annex M2 (07/200 1 ) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Infrastructure of audiovisual services - Communic
3、ation procedures Gateway control protocol Annex M2: Media Gateway resource congestion handling package ITU-T Recommendation H.248 - Annex M2 (Formerly CCITT Recommendation) ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS INFRASTRUCTURE OF
4、 AUDIOVISUAL SERVICES General Transmission multiplexing and synchronization Systems aspects Communication procedures Coding of moving video Related systems aspects SYSTEMS AND TERMINAL EQUIPMENT FOR AUDIOVISUAL SERVICES SUPPLEMENTARY SERVICES FOR MULTIMEDIA H. 100-H. 199 H.200-H.219 H.220-H.229 H.23
5、0-H.239 H.240-H.259 H.260-H.279 H.280-H.299 H.300-H.399 H.450-H.499 I For further details, please refer to the list of ITU-T Recommendations. ITU-T Recommendation H.248 Gateway control protocol ANNEX M2 Media Gateway resource congestion handling package Summary This annex describes a package for Med
6、ia Gateway Resource Congestion Handling for use with the H.248 Gateway Control Protocol. As defined in ITU-T H.248, a “package“ is an extension to H.248 that supports specific behaviour. Source Annex M2 to ITU-T Recommendation H.248 was prepared by ITU-T Study Group 16 (2001-2004) and approved under
7、 the WTSA Resolution 1 procedure on 29 July 2001. ITU-T H.248/Annex M2 (07/2001) 1 FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of IT
8、U. 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), which meets every four years, establishes the topics f
9、or 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 within ITU-Ts purview, the necessary standards are prepared
10、 on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practic
11、e 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 members or others outside of the Recommendation developme
12、nt process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore stro
13、ngly urged to consult the TSB patent database. o mu 2001 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from ITU. 11 ITU-T H.248/Annex M2 (07/200
14、1) TABLE OF CONTENTS M2.1 Scope . M2.2 Definitions M2.3 References M2.4 Congestion Handling Package M2.4.1 Properties M2.4.2 Events M2.5 Signals M2.6 Statistics . M2.7 Procedures ITU-T H.248IAnnex M2 (07/2001) Page 1 1 1 2 2 . U1 ITU-T Recommendation H.248 Gateway control protocol ANNEX M2 Media Gat
15、eway resource congestion handling package M2.1 Scope This annex describes a package for the H.248 gateway protocol related to Media Gateway Resource Congestion Handling. With the root termination implementing this package, a gateway is expected to report congestion events to a Media Gateway Controll
16、er (MGC). M2.2 Definitions M2.3 References M2.4 Congestion Handling Package Package Name: CHP PackageID: chp, 0x0029 Description: The package makes it possible for the MG to control its load. The events in this package may be provisioned in the MG. The event in this package may only be applied to th
17、e Root termination. Version: 1 Extends: None M2.4.1 Properties NA M2.4.2 Events M2.4.2.1 MGCongestion Event name: MGCon EventID: mgcon, (0x0001) Description: This event occurs when the MG requires that the MGC start or finish load reduction towards the MG or to adjust the Load Reduction Percentage.
18、The event is ordered by the MGC or provisioned. EventsDescriptor Parameters: None ITU-T H.248/Annex M2 (07/2001) 1 ObservedEventsDescriptor Parameters Parameter Name: Reduction Pa ram et e rID : Type: Integer Possible Values: o- 1 O0 It represents a percentage of the load that the MGC is requested t
19、o block (reject or deflect). A value of O means that no reduction shall be applied. A value of 100 means that the MGC shall block all load towards the MG that is possible to block. reduction, (0x0001) M2.5 Signals NA M2.6 Statistics NA M2.7 Procedures When the MGC receives a load reduction notificat
20、ion it tries to reduce the processing load that it creates on the MG according to the parameter value. For example, if the Reduction Percentage is 20 then the MGC shall try to block 20% of the load that it would otherwise (without any reduction) have generated on the MG. It is left to the implementa
21、tion to decide how the MGC shall translate a load reduction of 20% to a certain concrete action. One possible implementation is to reject (or redirect) a percentage of new calls based on 20% of the current calls in the MG. Another possibility is to block 20% of the commands that create new contexts.
22、 The MGC is free to support priorities by blocking low priority calls (originating normal calls) in the first place when load reduction is requested. If calls of different priority generate very different load on the MG and load reduction is implemented by rejecting a certain fraction of the calls t
23、hen it is recommended to give each call a weight proportional to the average load it is expected to create. 2 ITU-T H.248/Annex M2 (07/2001) SERIES OF ITU-T RECOMMENDATIONS Series A Series B Series C Series D Series E Series F Series G Series H Series I Series J Series K Series L Series M Series N S
24、eries O Series P Series Q Series R Series S Series T Series U Series V Series X Series Y Series Z Organization of the work of ITU-T Means of expression: definitions, symbols, classification General telecommunication statistics General tariff principles Overall network operation, telephone service, s
25、ervice operation and human factors Non-telephone telecommunication services Transmission systems and media, digital systems and networks Audiovisual and multimedia systems Integrated services digital network Cable networks and transmission of television, sound programme and other multimedia signals
26、Protection against interference Construction, installation and protection of cables and other elements of outside plant TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: international sound programme and televi
27、sion transmission circuits Specifications of measuring equipment Telephone transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminals for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communications Global information infrastructure and Internet protocol aspects Languages and general software aspects for telecommunication systems Printed in Switzerland Geneva, 2001
