1、 International Telecommunication Union ITU-T H.248.40TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2013) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Communication procedures Gateway control protocol: Application data inactivity detection package Recommend
2、ation ITU-T H.248.40 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 pr
3、ocedures 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 multimedia
4、 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 collaboration applic
5、ations 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 BROADBAND, T
6、RIPLE-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 aspects H.700H.7
7、19 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 refer to the
8、 list of ITU-T Recommendations. Rec. ITU-T H.248.40 (03/2013) i Recommendation ITU-T H.248.40 Gateway control protocol: Application data inactivity detection package Summary Recommendation ITU-T H.248.40 describes the principle used to detect application data inactivity for IP transport connections
9、in general, like e.g., avoid a potential situation of deadlock if latching was set but no application data stream is incoming to latch on. The solution is based on an event to detect if application data had stopped (or not started). This revision provides additional information regarding the setting
10、 of the detection time for the IP flow stop event. History Edition Recommendation Approval Study Group 1.0 ITU-T H.248.40 2007-01-13 16 2.0 ITU-T H.248.40 2013-03-16 16 ii Rec. ITU-T H.248.40 (03/2013) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency
11、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 issuing Recommendations on them with a view to
12、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 these topics. The approval of ITU-T Recommendations
13、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 expression “Administration“ is used for conciseness t
14、o 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 applicability) and compliance with the Recommendation is
15、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 Recommendation is required of any party. INTELLEC
16、TUAL 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 applicability of claimed Intellectual Property Rights, wheth
17、er 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 this Recommendation. However, implementers are cau
18、tioned 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 whatsoever, without the prior written permission of
19、 ITU. Rec. ITU-T H.248.40 (03/2013) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Terms and definitions . 1 4 Abbreviations and acronyms 1 5 Conventions 2 6 Application data inactivity detection package 2 6.1 Properties 2 6.2 Events . 2 6.3 Signals 3 6.4 Statistics 3 6.5 Error codes 4 6.6 P
20、rocedures 4 Appendix I Example use case for voice-over-RTP . 5 I.1 Introduction 5 I.2 Abbreviations . 5 I.3 Assumptions . 5 I.4 Example detection logic . 5 I.5 Recommendations for timer settings 6 Appendix II Example use case for deadlock detection in IP latching scenarios . 7 II.1 Introduction 7 II
21、.2 Assumptions . 8 II.3 Example detection logic . 8 II.4 Recommendations for timer settings 8 Appendix III Example use case for detection of a hanging voice over RTP session . 9 III.1 Introduction 9 III.2 Abbreviations and acronyms 9 III.3 Incorrect termination of a Voice over RTP session 9 III.4 Re
22、lation of “hanging RTP session“ with “hanging ITU-T H.248 termination“ 10 Bibliography. 11 Rec. ITU-T H.248.40 (03/2013) 1 Recommendation ITU-T H.248.40 Gateway control protocol: Application data inactivity detection package 1 Scope This Recommendation allows a media gateway controller to request th
23、e media gateway to detect that after a certain period of time no Internet protocol application data has flowed on a particular termination/stream. The ability to detect if Internet protocol application data flow has stopped or has not started is useful to avoid deadlock in latching scenarios and als
24、o may be of use to detect hanging bearers. This Recommendation defines an event which is related to one or more IP 2-tuples. An individual 2-tuple is given by of an IP flow of an ITU-T H.248 stream or termination. The set of conditions for inactivity detection is related to IP packet arrival and/or
25、departure events for all 2-tuples of a stream/termination. The condition of packet arrivals or departures respectively is controlled via a dedicated parameter (called “direction“). The flexibility of inactivity detection logic configurations allows the usage of ITU-T H.248.40 for various application
26、s (see also the appendices). 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 editions indicated were valid. All Recommendations and other refe
27、rences 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 valid ITU-T Recommendations is regularly published. The reference
28、 to a document within this Recommendation 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 (2013), Gateway control protocol: Version 3. 3 Terms and definitions None. 4 Abbreviations and acronyms This Recommendation uses the follo
29、wing abbreviations and acronyms: ADID Application Data Inactivity Detection IP Internet Protocol LD Local Descriptor MG Media Gateway MGC Media Gateway Controller NAPT Network Address and Port Translation RD Remote Descriptor RTCP RTP Control Protocol RTP Real-Time Transport Protocol RTSP Real-Time
30、Streaming Protocol 2 Rec. ITU-T H.248.40 (03/2013) 5 Conventions None. 6 Application data inactivity detection package Package name: Application data inactivity detection package Package ID: adid (0x009c) Description: This package enables the MGC to be notified when the MG has detected that no IP ap
31、plication data flow has been detected on a termination/stream. Version: 1 Extends: None 6.1 Properties None. 6.2 Events 6.2.1 IP flow stop detection Event name: IP flow stop detection Event ID: ipstop (0x0001) Description: This event detects if there has been no direction-dependent application data
32、for a set (detection time) interval of time. In cases where it has been indicated that multiple IP ports are associated with a flow (e.g., RTP and RTCP), the detection of no application data flow must be done on all ports before the event is triggered. When applied at a termination level the adid/ip
33、stop event shall be notified when it has been determined that application data has stopped on all of the streams associated with the termination. If, after the initial reporting of the event, and if the event remains active, the detection time elapses without detection of application data, the event
34、 is reported again. This may occur multiple times. This event shall be detected irrespective of the StreamMode. For example, even if the stream is set to SendOnly and packets are received, this will be taken into account. 6.2.1.1 EventDescriptor parameters 6.2.1.1.1 Detection time Parameter name: De
35、tection time Parameter ID: dt (0x0001) Description: This is the interval of time after which if no application data flow is detected, the IP Flow Stop Detection event is triggered. The MG checks over intervals of detection time dt if any application data traffic has occurred. If no application data
36、has arrived, then the adid/ipstop event is triggered. NOTE This may result that more than the detection time has passed between the IP data flow stop and the detection of the event. Rec. ITU-T H.248.40 (03/2013) 3 Type: Integer Optional: Yes (if default is provisioned). Possible values: Any positive
37、 number of seconds. Default: Provisioned NOTE: a) Application-independent versus application-specific values: Either a single, global default value or multiple, application specific default values may be provisioned. There is typically a single value configured in case of a provisioning approach, va
38、lid for all applications. Multiple, application-specific default values could be also provisioned. The value selection could be tied to application information like the LD/RD-embedded media description. The specific selection method is out of scope of this package definition and may be e.g., defined
39、 in an ITU-T H.248 profile specification. b) Stream- versus Termination-level event arming: When applied at a Termination level, where might be aggregated traffic based on multiple applications (in case of multiple streams). The value selection may be again application-specific or a single value. Ho
40、wever in this case value selection must be based on the fact that the event will be notified when only all streams on the Termination have timed out. 6.2.1.1.2 Direction Parameter name: Direction Parameter ID: dir (0x0002) Description: With this parameter, the MGC indicates to the MG which direction
41、 of the data flow should be monitored to detect inactivity. Incoming direction means from the outside of the context. Outgoing direction means towards the outside of the context. If direction is set to “BOTH“, the MG will generate the event if no data is sent nor received on the termination to/from
42、the outside of the context for an interval of detection time dt. Type: Enumeration Optional: Yes Possible values: “IN“ (0x0001) Incoming direction “OUT“ (0x0002) Outgoing direction “BOTH“ (0x0003) Both directions Default: Both 6.2.1.2 ObservedEventsDescriptor parameters None. 6.3 Signals None. 6.4 S
43、tatistics None. 4 Rec. ITU-T H.248.40 (03/2013) 6.5 Error codes None. 6.6 Procedures To detect application data inactivity, the MGC should set the adid/ipstop event with an appropriate “detection time“ and the appropriate “direction“ on the applicable ITU-T H.248 Stream/Termination. The adid/ipstop
44、event is notified to the MGC: If the MGC has set dir to “IN“ and no IP data packets have been received by the MG from the network in that stream/termination by the expiry of the detection time (dt). If the MGC has set dir to “OUT“ and no IP data packets have been sent by the MG to the network in tha
45、t stream/termination by the expiry of the detection time (dt). If the MGC has set direction to “BOTH“ and no IP data packets have been sent to nor received from the network in that stream/termination by the expiry of the detection time (dt). On reception of a NOTIFY.req with the adid/ipstop event, t
46、he MGC should take appropriate action. The triggered action on MGC level may have to take into account: Service features (e.g., unidirectional applications, muted microphone in conference services, etc.). Bearer service configuration settings (e.g., enabled silence suppression mode in case of speech
47、 telephony, RTP sessions without RTCP, etc.). ITU-T H.248 Termination configurations (e.g., ITU-T H.248 StreamMode Property equals “Inactive“). It is recommended to set timer detection time (dt) with a relevant value, e.g., a multiple of half the round-trip delay or a multiple of the typical packet
48、interarrival time. The mean interarrival time may be IP application-specific (e.g., codec type), may depend on application level framing protocol usage (e.g., RTP packetization time, RTCP transmission interval, etc.) or service-specific (e.g., muted microphone in case of voice over RTP, or suspended
49、 streaming in case of RTSP-controlled multimedia streaming). Rec. ITU-T H.248.40 (03/2013) 5 Appendix I Example use case for voice-over-RTP (This appendix does not form an integral part of this Recommendation.) I.1 Introduction This Recommendation may be applied on ephemeral terminations, which are used for two-party voice-over-RTP (VoRTP) service realizations. The RTP packet transmission interval is here much smaller than the granularity of timer “ipstop/dt“. This appendix illustrates the detection of “RTP media stop“.
