1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T Series E.800 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 2 (11/1988) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Telephone network management and traffic engineering Curves showing the relatio
2、n between the traffic offered and the number of circuits required ITU-T E.800-series Recommendations Supplement 2 (Formerly CCITT Recommendations) ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS INTERNATIONAL OPERATION Definitions E.10
3、0E.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 telephone service E.160E.169 International routing plan E.170E.179 Tones in national signalling
4、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 IN THE INTERNATIONAL TELEPHONE SERVICE Charging in the international telephone service E.23
5、0E.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 ISDN PROVISIONS CONCERNING USERS E.330E.349 INTERNATIONAL ROUTING PLAN E.350E.399 NETWORK M
6、ANAGEMENT International service statistics E.400E.409 International network management E.410E.419 Checking the quality of the international telephone service E.420E.489 TRAFFIC ENGINEERING Measurement and recording of traffic E.490E.505 Forecasting of traffic E.506E.509 Determination of the number o
7、f 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 IP-networks E.650E.699 ISDN traffic engineering E.700E.749 Mobile network traffic engineer
8、ing 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 telecommunication services E.810E.844 Objectives for quality of service and related concepts
9、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 and services E.880E.899 For further details, please refer to the list of ITU-T Recommenda
10、tions. E.800 series Supplement 2 (11/1988) i Supplement 2 to ITU-T E.800-series Recommendations Curves showing the relation between the traffic offered and the number of circuits required Source Supplement 2 was approved in Melbourne (1988) and originally published in Blue Book, Fascicle II.3. ii E.
11、800 series Supplement 2 (11/1988) 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 ITU. ITU-T is responsible for studying technical, o
12、perating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T study groups which, in tu
13、rn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSC 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. NOT
14、E In this publication, 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 practice or implementation of this publication may involv
15、e 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 publication development process. As of the date of approval of this publicati
16、on, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this publication. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. ITU 2002 Al
17、l rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. E.800 series Supplement 2 (11/1988) 1 Supplement 2 to ITU-T E.800-series Recommendations Curves showing the relation between the traffic offered and the number of c
18、ircuits required T0209450-02123456701238 9 10 11 12 13 14 15 16 17 18 19 2045678910111213141516171819201 %3 %5 %7 %Curve forsmall groupsof automaticcircuitsCCITTTableBCCITTTableAErlang curvesRelation between the traffic (in Erlangs) offered and the number of circuits required in the case of: the cur
19、ves A and B of Table 1/E.510; the Erlang formula (p = 1 %, 3 %, 5 % and 7 %); the curve for small groups of automatic circuits (see Annex A to Recommendation E.520).Traffic offered (in Erlangs)NumberofcircuitsFIGURE 1 Number of circuits between 1 and 20 2 E.800 series Supplement 2 (11/1988) T0209460
20、-0210 20 30 400102050 60 70 80 90 100304050607080901001 %3 %5 %7 %Traffic offered (in Erlangs)NumberofcircuitsRelation between the traffic (in Erlangs) offered and the number of circuits required in the case ofthe Erlang formula for (p = 1 %, 3 %, 5% and 7 %).FIGURE 2 Number of circuits between 1 an
21、d 100 Printed in Switzerland Geneva, 2002 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series B Means of expression: definitions, symbols, classification Series C General telecommunication statistics Series D General tariff principles Series E Overall network operation,
22、 telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmi
23、ssion of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation and protection of cables and other elements of outside plant Series M TMN and network maintenance: international transmission systems, telephone circuits, te
24、legraphy, facsimile and leased circuits Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Telephone transmission quality, telephone installations, local line networks Series Q Switching and signalling Seri
25、es R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks and open system communications Series Y Global information infrastructure and Internet protocol aspects Series Z Languages and general software aspects for telecommunication systems *21965*
