1、 International Telecommunication Union ITU-T Q.3925TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2012) SERIES Q: SWITCHING AND SIGNALLING Signalling requirements and protocols for the NGN Testing for next generation networks Traffic flow types for testing quality of service parameters on model
2、 networks Recommendation ITU-T Q.3925 ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE Q.1Q.3 INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Q.4Q.59 FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.60Q.99 CLAUSES APPLICABLE TO ITU-T
3、 STANDARD SYSTEMS Q.100Q.119 SPECIFICATIONS OF SIGNALLING SYSTEMS No. 4, 5, 6, R1 AND R2 Q.120Q.499 DIGITAL EXCHANGES Q.500Q.599 INTERWORKING OF SIGNALLING SYSTEMS Q.600Q.699 SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 Q.700Q.799 Q3 INTERFACE Q.800Q.849 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 Q.850
4、Q.999 PUBLIC LAND MOBILE NETWORK Q.1000Q.1099 INTERWORKING WITH SATELLITE MOBILE SYSTEMS Q.1100Q.1199 INTELLIGENT NETWORK Q.1200Q.1699 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q.1700Q.1799 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) Q.1900Q.1999 BROADBAND
5、 ISDN Q.2000Q.2999 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR THE NGN Q.3000Q.3999 General Q.3000Q.3029 Network signalling and control functional architecture Q.3030Q.3099 Network data organization within the NGN Q.3100Q.3129 Bearer control signalling Q.3130Q.3179 Signalling and control requirements
6、and protocols to support attachment in NGN environments Q.3200Q.3249 Resource control protocols Q.3300Q.3369 Service and session control protocols Q.3400Q.3499 Service and session control protocols supplementary services Q.3600Q.3649 NGN applications Q.3700Q.3849 Testing for next generation networks
7、 Q.3900Q.3999For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Q.3925 (03/2012) i Recommendation ITU-T Q.3925 Traffic flow types for testing quality of service parameters on model networks Summary Recommendation ITU-T Q.3925 describes the types of traffic flows which
8、 should be generated for testing QoS parameters for voice, data, and video on the model network. The characteristics of traffic flows are determined for different types of services, content, and networks (voice, voice over Internet Protocol (VoIP), Web surfing, file transfer, e-mail, peer-to-peer, v
9、ideo, and ubiquitous sensor networks conditions). History Edition Recommendation Approval Study Group 1.0 ITU-T Q.3925 2012-03-29 11 ii Rec. ITU-T Q.3925 (03/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, in
10、formation 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 standardizing telecommunications on a
11、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 is covered by the procedure laid down
12、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 to indicate both a telecommunication ad
13、ministration 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 achieved when all of these mandatory p
14、rovisions 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. INTELLECTUAL PROPERTY RIGHTS ITU draws attenti
15、on 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, whether asserted by ITU members or others o
16、utside 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 cautioned that this may not represent the
17、 latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2012 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 Q.3925 (03/2012) iii
18、Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 4 Abbreviations and acronyms 2 5 Conventions 2 6 Traffic flow types in the public telecommunication networks . 2 6.1 Poisson traffic . 2 6.2 Self-similar traffic 2 7 Voice traffic flow characteristics 3 7.1 Voice traffic flow character
19、istics in accordance with Recommendation ITU-T Q.543 . 3 7.2 Voice traffic flow features in NGNs 3 8 Data traffic flow characteristics 4 8.1 “www“ traffic flow characteristics . 4 8.2 File transfer traffic flow characteristics 4 8.3 E-mail traffic flow characteristics 4 8.4 Peer-to-peer traffic flow
20、 characteristic . 4 9 Video traffic flow characteristic . 4 10 Characteristics of the traffic flow on ubiquitous sensor networks . 4 11 Security considerations . 5 Bibliography. 6 Rec. ITU-T Q.3925 (03/2012) 1 Recommendation ITU-T Q.3925 Traffic flow types for testing quality of service parameters o
21、n model networks 1 Scope The Q.39xx-series of Recommendations relates to testing methods and specifications for model networks. The model network concept was created in 2006 due to the complexity of next generation network (NGN) equipment over digital networks, the unlimited services set in principl
22、e, the level of guaranteed quality of service (QoS) for separated QoS classes, and so on. The global interoperability concept was also created as a next step in testing methodology. Global interoperability includes the interoperability of technical means, of services, and of QoS classes and paramete
23、rs. The modern type of traffic is required to realize the testing of global interoperability on the model network. In general, voice traffic flow has been digital network traffic flow. Over a long period of time, voice traffic flow characteristics were obtained in the real networks and these charact
24、eristics are standardized in ITU-T Q.543, in accordance with statistical data. The NGN traffic contains voice traffic, data traffic, and video traffic. As a rule, data and video traffic have different characteristics than voice traffic in the circuit switched network. Data and video traffic in the N
25、GN are self-similar. Consequently, the new methods for traffic generation and modelling should be used in the testing procedure for global interoperability. This Recommendation describes the voice, data, and video traffic flow characteristics which should be generated for testing global interoperabi
26、lity parameters on the model network. Traffic characteristics of the ubiquitous sensor network (USN) are also described in this Recommendation. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of thi
27、s 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 the possibility of applying the most recent edition of the Recommendations and other
28、 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 Recommendation. ITU-T P.59 Recommendation ITU-T P.59 (1993), Artificial conversati
29、onal speech. ITU-T Q.543 Recommendation ITU-T Q.543 (1993), Digital exchange performance design objectives. ITU-T Q.3900 Recommendation ITU-T Q.3900 (2006), Methods of testing and model network architecture for NGN technical means testing as applied to public telecommunication networks. ITU-T Y.1541
30、 Recommendation ITU-T Y.1541 (2011), Network performance objectives for IP-based services. ITU-T Y.1901 Recommendation ITU-T Y.1901 (2009), Requirements for the support of IPTV services. 3 Definitions None. 2 Rec. ITU-T Q.3925 (03/2012) 4 Abbreviations and acronyms This Recommendation uses the follo
31、wing abbreviations and acronyms: BHCA Busy Hour Call Attempts IPTV Internet Protocol Television ISDN Integrated Services Digital Network NGN Next Generation Network VoIP Voice over Internet Protocol USN Ubiquitous Sensor Network 5 Conventions None. 6 Traffic flow types in the public telecommunicatio
32、n networks 6.1 Poisson traffic The voice traffic arrival process for circuit switched public telecommunication networks is the Poisson process based on long-term observation. The fundamental properties of the Poisson process are stationary, independent at all time instants (epochs), and simple. The
33、following two most important Poisson process properties could be considered b-Iversen: the number of events within a time interval of fixed length is Poisson distributed, the time distance between consecutive events is exponentially distributed. The Poisson flow is fully determined by its own parame
34、ter. The Poisson arrival process is adequate for submission of other arrival processes, for example the dial-up Internet access arrival process b-Iversen. 6.2 Self-similar traffic Both the data and video traffic creating the new types of arrival traffic flows in NGNs are self-similar traffic flows.
35、The arrival traffic process is considered as self-similar if the distribution function for the original and the aggregated processes are equal. The aggregated arrival process is created by the averaging of the original process in m size series blocks (the block is part of the original process) b-Wil
36、linger. The most important feature of the self-similar arrival process is the Hurst parameter b-Sheluhin. Knowledge of the Hurst parameter value gives the possibility to generate the self-similar flow with specified characteristics. The Hurst parameter, H, could be determined as follows: )()()1(2)(X
37、DmXDHm = Where )()(mXD is the aggregated flow variance and D(X) is the original flow variance. Rec. ITU-T Q.3925 (03/2012) 3 The next equation is frequently used: )ln()22()()(ln)(mHXDXDm=The expression (2H2) is a next geometrical sense. This is the line slope coefficient. This line is approximated b
38、y the following function: ()ln()()(ln)(mfXDXDm=7 Voice traffic flow characteristics 7.1 Voice traffic flow characteristics in accordance with Recommendation ITU-T Q.543 The originating voice traffic flow characteristics are shown in Table 1, based on Table 1a of ITU-T Q.543. The originating traffic
39、flow for ISDN subscribers is not considered since there are significantly fewer ISDN subscribers than PSTN subscribers. The intensity of traffic flow in Erlangs and busy hour call attempts (BHCA) are shown in Table 1 for normal level load type A. For testing the QoS parameters on the model network f
40、or overload conditions, the values from Table 1 should be increased up to 25% in Erlangs and 35% in busy hour call attempts (level load type B), in accordance with clause 2.1.2.2 of ITU-T Q.543. Table 1 Originating voice traffic flow characteristics Traffic flow class Flow type Average traffic inten
41、sity (Erlang) Average number of busy hour call attempts (BHCA) 1 Poisson 0.03 1.22 Poisson 0.06 2.4 3 Poisson 0.10 4 4 Poisson 0.17 6.8 The superposition of traffic flow classes should be used during testing on the model network. The superposition of N independent Poisson processes will be the Poiss
42、on process in accordance with the Poisson superposition theorem b-Iversen. The shares of traffic flow classes in the superposition flow are determined by the concrete characteristics of the network or network part which should be tested. If the incoming traffic flow should be generated, its characte
43、ristics are to be taken as for originating traffic. 7.2 Voice traffic flow features in NGNs The voice traffic flow features in NGNs are determined by the voice traffic transfer over IP Protocols (VoIP). The VoIP user share is constantly increased, but the voice traffic characteristics from Table 1a
44、of ITU-T Q.543 are very stable and could be used for VoIP average traffic intensity and the average number of busy hour call attempts (BHCA). The statistical observation of VoIP traffic flows on the real networks proved that the arriving VoIP traffic flow could be described by the Poisson process. F
45、urthermore, the Poisson traffic flow model could be used for VoIP traffic, even for all-IP networks b-Birke. 4 Rec. ITU-T Q.3925 (03/2012) The silence suppression methods could be used during VoIP traffic processing. Methods used in ITU-T P.59 can be considered for the VoIP traffic generation for th
46、e model network. The talk-spurt duration and pause duration submit the exponential distribution in accordance with ITU-T P.59. In conversation, the pause share duration is 61.47% and the mutual silence share duration is 22.48%. 8 Data traffic flow characteristics 8.1 “www“ traffic flow characteristi
47、cs The “www“ traffic is self-similar with the Hurst parameter H = 0.7-0.9 b-Crovella and b-Ho. 8.2 File transfer traffic flow characteristics File transfer traffic is self-similar with the Hurst parameter H = 0.85-0.95 b-Norros and b-Jena. 8.3 E-mail traffic flow characteristics E-mail traffic is se
48、lf-similar with the Hurst parameter H = 0.75 b-Ho. 8.4 Peer-to-peer traffic flow characteristic Peer-to-peer traffic is self-similar. The Skype traffic as P2P traffic example is self-similar with H = 0.6 for inter-arrival time and H = 0.7 for packet lengths b-Markovich. 9 Video traffic flow characte
49、ristic The IPTV traffic flow statistical observation proved that the traffic flows are self-similar both for multicast and unicast traffic b-Janevski, b-Tarasov and b-Mellia. The Hurst parameter values are H = 0.55-0.6 for multicast traffic and H = 0.75-0.8 for unicast traffic. The traffic flow characteristics for video traffic generation on the model network are shown in Table 2. Table 2 IPTV traffic flow characteristics Traffic types Flow types H values Multicast Se
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