1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T E.847 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2017) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Quality of telecommunication services: concepts, models, objectives
2、 and dependability planning Objectives for quality of service and related concepts of telecommunication services Quality of service norms for time-division multiplexing interconnection between telecom networks Recommendation ITU-T E.847 ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEP
3、HONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS INTERNATIONAL OPERATION Definitions E.100E.103 General provisions concerning Administrations E.104E.119 General provisions concerning users E.120E.139 Operation of international telephone services E.140E.159 Numbering plan of the international teleph
4、one service E.160E.169 International routing plan E.170E.179 Tones in national signalling systems E.180E.189 Numbering plan of the international telephone service E.190E.199 Maritime mobile service and public land mobile service E.200E.229 OPERATIONAL PROVISIONS RELATING TO CHARGING AND ACCOUNTING I
5、N THE INTERNATIONAL TELEPHONE SERVICE Charging in the international telephone service E.230E.249 Measuring and recording call durations for accounting purposes E.260E.269 UTILIZATION OF THE INTERNATIONAL TELEPHONE NETWORK FOR NON-TELEPHONY APPLICATIONS General E.300E.319 Phototelegraphy E.320E.329 I
6、SDN PROVISIONS CONCERNING USERS E.330E.349 INTERNATIONAL ROUTING PLAN E.350E.399 NETWORK MANAGEMENT International service statistics E.400E.404 International network management E.405E.419 Checking the quality of the international telephone service E.420E.489 TRAFFIC ENGINEERING Measurement and recor
7、ding of traffic E.490E.505 Forecasting of traffic E.506E.509 Determination of the number of circuits in manual operation E.510E.519 Determination of the number of circuits in automatic and semi-automatic operation E.520E.539 Grade of service E.540E.599 Definitions E.600E.649 Traffic engineering for
8、IP-networks E.650E.699 ISDN traffic engineering E.700E.749 Mobile network traffic engineering E.750E.799 QUALITY OF TELECOMMUNICATION SERVICES: CONCEPTS, MODELS, OBJECTIVES AND DEPENDABILITY PLANNING Terms and definitions related to the quality of telecommunication services E.800E.809 Models for tel
9、ecommunication services E.810E.844 Objectives for quality of service and related concepts of telecommunication services E.845E.859 Use of quality of service objectives for planning of telecommunication networks E.860E.879 Field data collection and evaluation on the performance of equipment, networks
10、 and services E.880E.899 OTHER E.900E.999 INTERNATIONAL OPERATION Numbering plan of the international telephone service E.1100E.1199 NETWORK MANAGEMENT International network management E.4100E.4199 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T E.847 (03/2017) i R
11、ecommendation ITU-T E.847 Quality of service norms for time-division multiplexing interconnection between telecom networks Summary Recommendation ITU-T E.847 analyses and identifies quality of service (QoS) parameters for time-division multiplexing (TDM) interconnection between telecom networks, whi
12、ch are needed to facilitate effective interconnections with reasonable traffic handling capacities. The proposals, as given in this Recommendation, provide a guiding framework for TDM interconnection of telecom networks and will facilitate effective monitoring of performance, QoS at point of interco
13、nnections (POIs), as well as endeavour to ensure end-to-end customer satisfaction and quality of experience (QoE). Regulators may also use this Recommendation to envision effective interconnection regulations in their respective countries. History Edition Recommendation Approval Study Group Unique I
14、D* 1.0 ITU-T E.847 2017-03-01 12 11.1002/1000/13169 Keywords Link utilisation, mobile network operators, POI congestion, POI seizure, quality of experience (QoE), quality of service (QoS), TDM interconnection, telecom networks interconnection. * To access the Recommendation, type the URL http:/handl
15、e.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T E.847 (03/2017) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of tel
16、ecommunications, 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 standardizing telec
17、ommunications 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 is covered by the p
18、rocedure 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 to indicate both a t
19、elecommunication 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 achieved when all o
20、f 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. INTELLECTUAL PROPERTY RIGHT
21、SITU 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, whether asserted by ITU m
22、embers 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 cautioned that this may
23、 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 2017 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 E.8
24、47 (03/2017) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definition 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 QoS norms for TDM interconnection between telecom networks . 2 6.1 Subscriber attempt succes
25、s ratio for a POI . 3 6.2 POI seizure success ratio 3 6.3 Subscriber attempts-seizure success ratio 3 6.4 Inter-operator POI efficiency () 3 6.5 Time frame for activation of a new POI . 4 6.6 Time frame for POI capacity enhancement 4 6.7 Interconnection route utilisation parameter 4 6.8 Mean time to
26、 repair for POI ports 4 6.9 Time to repair interconnection route 4 6.10 Dual seizure ratio 4 6.11 Signalling link utilisation . 5 6.12 Unit of time measurement and recordings in CDRs . 5 6.13 Clock synchronisation and accuracy of switch time 5 6.14 Acceptance testing and monitoring 5 7 Review of inf
27、luences on QoS of TDM interconnection . 5 Annex A Guiding regulatory framework for interconnection 7 Appendix I Further guidance to regulators . 10 iv Rec. ITU-T E.847 (03/2017) Introduction In multi-operator, multi-technology and multi-service environments, it is imperative to ensure effective inte
28、rconnection between different operator networks in order to provide quality service to end users. To ensure effective time-division multiplexing (TDM) interconnection between networks, the network-related parameters to measure the quality of telecom services may relate to: network availability; conn
29、ection establishment (accessibility); connection maintenance (retainability); optimal point of interconnection (POI) capacity provisioning and its effective utilization; POI congestion (no. of POIs not meeting the benchmark). Interconnection in TDM networks can be considered relatively simple and we
30、ll established since all legacy telephone networks usually use the same signalling system (i.e., SS7 signalling), media transport as in TDM and numbering scheme such as that of Recommendation ITU-T E.164 and also interfaces such as E1 and T1 links that are well used depending on the region or networ
31、k equipment provider. From a regulatory point of view, the purpose of interconnection is to ensure end-to-end network service connectivity and enable consumers of interconnected operators to establish connections with one another. Access also enables service providers to utilise facilities of other
32、providers to further influence their own business plans for providing service to customers. Rec. ITU-T E.847 (03/2017) 1 Recommendation ITU-T E.847 Quality of service norms for time-division multiplexing interconnection between telecom networks 1 Scope This Recommendation is intended to facilitate e
33、ffective interconnection and support the following: non-discriminatory benchmarks for interconnection parameters, interconnect resources allocated to and congestion faced, if any, by outgoing as well as incoming traffic at point of interconnection (POI) of telecom networks; end-to-end quality of ser
34、vice (QoS) for users; prevention of under-utilization and over-provisioning of interconnect capacity and resources; flexibility and freedom for interconnecting parties to negotiate and finalise mutually agreeable interconnection arrangements. 2 References The following ITU-T Recommendations and othe
35、r 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; the users of this Recommendation are, therefore, encou
36、raged 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 Recommendation does not give it, as a stand-alone doc
37、ument, the status of a Recommendation. ITU-T E.600 Recommendation ITU-T E.600 (1993), Terms and definitions of traffic engineering. ITU-T E.800 Recommendation ITU-T E.800 (2008), Definitions of terms related to quality of service. ITU-T P.10 Recommendation ITU-T P.10/G.100 (2006), Vocabulary for per
38、formance and quality of service. ITU-T Q.700 series ITU-T Q.700-Q.799 series of Recommendations, Specifications of Signalling System No. 7. ITU-T Q.780 Recommendation ITU-T Q.780 (1995), Signalling System No.7 test specification General description. 3 Definition 3.1 Terms defined elsewhere This Reco
39、mmendation uses the following terms defined elsewhere: 3.1.1 QoE assessment: ITU-T P.10. 3.1.2 quality of service (QoS): ITU-T P.10 and ITU-T E.800. 3.1.3 quality of experience (QoE): ITU-T P.10. 3.1.4 time consistent busy hour (TCBH): ITU-T E.600. 2 Rec. ITU-T E.847 (03/2017) 3.2 Terms defined in t
40、his Recommendation This Recommendation defines the following terms: 3.2.1 interconnection: The physical and logical linking of public communications networks used by the same or a different service provider to allow the users of one service provider or network to communicate with users of another se
41、rvice provider or network, or to access services provided by another service provider or network. 3.2.2 POI (point of interconnection): The demarcated point or the facility for exchange of traffic between networks to facilitate inter-network communication of/for respective subscribers, who are end u
42、sers of such networks. 3.2.3 POI congestion: The ratio of calls failed over the POI (between two network operators) due to unavailability of free circuits to the total call requests for seizure of POI circuit. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acro
43、nyms: CDR Call Data Record DSR Dual Seizure Ratio KPI Key Performance Indicator MNO Mobile Network Operator MSC Mobile Switching Center MTTR Mean Time to Repair POI Point of Interconnection PSSR POI Seizure Success Ratio QoE Quality of Experience QoS Quality of Service SASR Subscriber Attempt Succes
44、s Ratio SASSR Subscriber Attempts-Seizure Success Ratio SLA Service Level Agreement TCBH Time Consistent Busy Hour TDM Time-Division Multiplexing TSP Telecom Service Provider 5 Conventions None. 6 QoS norms for TDM interconnection between telecom networks This clause shows some parameters and their
45、thresholds that aim to help network operators set measureable and realistic key performance indicators (KPIs) to ensure effective compliance of regulations and help them in negotiating interconnection agreements to mitigate unforeseen disputes. The following non-discriminatory benchmark parameters a
46、re proposed to be included for monitoring/observations by national regulators, to ensure effective performance and QoS of Rec. ITU-T E.847 (03/2017) 3 time-division multiplexing (TDM) interconnection, thereby resulting in improved quality of experience (QoE) for users. 6.1 Subscriber attempt success
47、 ratio for a POI subscriber attempt success ratio (SASR) = y/x Where: y = No. of successful attempts/call requests for seizure of circuit at a POI x = Total number of subscriber call attempts meant for that POI. An improved SASR means improvement in the success of subscribers call attempts toward a
48、particular POI and also leads to meting out of non-discriminatory treatment by telecom network/service providers to all POIs. It will also discourage intentional deterioration in QoS of a particular POI, with respect to delivery of end-to-end customer satisfaction (QoS/QoE). 6.2 POI seizure success
49、ratio POI seizure success ratio (PSSR) = z/y Where: z = No. of actual seizures at a POI y = No. of successful attempts/call requests for seizure at POI. Alternatively, POI congestion = (y-z)/y = 1 z/y POI congestion = failed call requests over the POI due to unavailability of free circuits (total call requests for seizure of POI circuit). NOTE The benchmark threshold for POI congestion may be set at 0.5%, i.e., 0.005, which means that out of 200 successful call attempts or seizure re
