1、 INTERNATIONAL TELECOMMUNICATION UNION D.20 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU GENERAL TARIFF PRINCIPLES SPECIAL TARIFF PRINCIPLES FOR THE INTERNATIONAL CIRCUIT-SWITCHED PUBLIC DATA COMMUNICATION SERVICES ITU-T Recommendation D.20 (Extract from the Blue Book) NOTES 1 ITU-T Recommendatio
2、n D.20 was published in Fascicle II.1 of the Blue Book. This file is an extract from the Blue Book. While the presentation and layout of the text might be slightly different from the Blue Book version, the contents of the file are identical to the Blue Book version and copyright conditions remain un
3、changed (see below). 2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. ITU 1988, 1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or b
4、y any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. Fascicle II.1 - Rec. D.20 1 Recommendation D.20 Fascicle II.1 - Rec. D.20 SPECIAL TARIFF PRINCIPLES FOR THE INTERNATIONAL CIRCUIT-SWITCHED PUBLIC DATA COMMUNICATION SERVICES (Gene
5、va, 1980) Preamble This Recommendation, which should be applied in conjunction with the provisions of Recommendation D.10, sets out the special tariff principles intended for application to the international circuit-switched public data communication service by means of public data networks. Definit
6、ion The circuit-switched data communication service is defined as follows: A service requiring the establishment of a circuit-switched data connection before data can be transferred between data terminal equipments. 1 Tariff structure 1.1 Tariff components 1.1.1 The tariff for the service should nor
7、mally consist of two components: a network access component; a network utilization component. 1.1.2 The network access component, normally intended to cover the cost of making the service available, represents the cost of the service which is not dependent on network utilization. It corresponds to w
8、hat is generally known as the “network connection charges”. 1.1.3 The network utilization component normally covers the costs which are dependent on network utilization. 1.2 Network access component 1.2.1 Access charges should be levied for each subscription and should normally be independent of net
9、work utilization. They may consist of: a) an initial fee (non-recurring); b) a subscription rental (payable at certain intervals, e.g. monthly or quarterly, until the subscription is terminated). 1.2.2 Different access charges may apply for access from other public-switched networks, e.g. from the p
10、ublic telephone network to the circuit-switched data network. 1.2.3 The access charges may vary according to the user class of service and/or the geographical position of the connection in each country and/or the means of access to the service, or there may be single flat-rate charges irrespective o
11、f the user class of service, geographical position or means of access. 1.2.4 The access charges shall not be included in international accounts between Administrations and their establishment is strictly a national matter. 2 Fascicle II.1 - Rec. D.20 1.3 Network utilization component 1.3.1 Compositi
12、on Charges for network utilization may consist of: a) for successful calls a call set-up charge, a minimum charge, a communication charge; b) for unsuccessful calls a call attempt charge. 1.3.2 Call set-up and call attempt charges 1.3.2.1 These charges may vary according to: user class of service; g
13、eographical distance between the data terminal equipments (DTEs); day of the week/time of the day; other factors. 1.3.2.2 These charges may be either fixed amount or amounts set in relation to the communication charge (see 1.3.4); for example, they may correspond to the charge for a communication of
14、 a certain duration. 1.3.2.3 The call attempt charge should not apply if an unsuccessful call attempt is due to congestion or a fault in the Administrations equipment. 1.3.3 Minimum charge Normally, the amount of the minimum charge is equal to the charge for a communication of a certain duration (se
15、e 1.3.4). 1.3.4 Communication charge 1.3.4.1 The communication charge depends on the duration of the communication and may vary according to: user class of service; geographical distance between the DTEs; day of the week/time of the day; other factors. 1.3.4.2 The duration of a communication is dete
16、rmined according to the time during which two DTEs are connected to each other. The duration should be measured in seconds or fractions of a second. 1.3.4.3 The communication charge is expressed as a charge per minute. 2 Collection charges 2.1 The establishment of the collection charge is a national
17、 matter. Whilst in general, Administrations correlate collection charges and accounting rates, it is recognized that the two may not necessarily be the same. 2.2 As a general principle, Administrations should make every effort to avoid too large a dissymetry between the collection charges applicable
18、 in each direction of the same relation. Fascicle II.1 - Rec. D.20 3 3 International accounting 3.1 Accounting rate shares corresponding only to the communication charges ( 1.3.4 of this Recommendation) should be established. No international accounting should take place as regards other possible ch
19、arges for network utilization. 3.2 The accounting rates should be expressed as a rate per minute. 3.3 For international accounting purposes, the duration of communications should be established in accordance with the provisions of 1.3.4.2. 3.4 Normally, the accumulated sum of communication duration
20、between the Administrations concerned during one month should be used for calculating the remuneration due to each Administration. 4 Determination of accounting rates 4.1 The accounting rates agreed between Administrations should normally be based on costs obtained through cost studies carried out b
21、y the Administrations. 4.2 When, for different reasons, Administrations are not able to make cost studies, the accounting rates for circuit-switched public data traffic could be related to the accounting rate applied for telephone traffic in the same relation. Thus the accounting rate (including pos
22、sible transit shares) for data traffic could be achieved by multiplying the accounting rate for telephone traffic by suitable coefficients. The coefficients indicated below have been used in the European Region and could serve as guidance for Administrations: Signalling rate Coefficient a)2400 bit/s 4800 bit/s 9600 bit/s 0.70 1.00 1.50 a)The values of the coefficients are subject to further study. 4.3 For the remuneration of the costs of transit facilities Administrations may agree to apply fixed transit rates.
