1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 % TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%0(/.%G0G0.%47/2+G0G0!.$G0G0)3$./0%2!4)/. G0G0.5-“%2). G0G02/54).!.$G0G0-/“),%G0G03%26)#%“!3)#G0G04%#(.)#!,G0G002/“,%-3#/.#%2.).G0G04(%G0G0-%!352%-%.4!.$G0G02%#/2$).G0G0/ the holding time for a given call
2、duration may thus be extremely variable1).2 Discrimination between automatic and semiautomatic callsSince different accounting procedures are used for automatic and semiautomatic calls, the recording apparatusmust be capable of distinguishing between these two types of calls and must record the call
3、 duration of automatic callsonly.Discrimination can be effected by one of the following methods:a) by connecting the measuring apparatus to a point in the exchange through which only automatic traffic isrouted;b) by recording call durations only for calls containing the discriminating digit 0 used i
4、n automatic working(see the Recommendation Q.104 cited in 2).Method b) may be particularly useful when both automatic and semiautomatic calls originate at exchangeswithin the national network and are routed to the outgoing international exchange over a common group of circuits.3 Omission of internat
5、ional transit traffic from the records of call durationAll records of call duration will be taken in the outgoing country and will relate to calls originating in thatcountry. It will therefore be necessary, in an international exchange which routes both terminal and international transittraffic, to
6、exclude the call duration of international transit calls passing through the exchange.It will be difficult to discriminate between originated calls and transit calls on the outgoing international circuitsand it may therefore be necessary to segregate this traffic within the exchange and connect the
7、recording apparatus at apoint in the exchange where transit traffic is not encountered._1)In Recommendation D.150, 4.1.4 1 holding time is not recommended because of the wide variations between chargeabletime and holding time in different relations and in different call types, which makes the use of
8、 holding time inappropriate forremunerating Administrations of countries of destination.2 Fascicle II.2 - Rec. E.2604 Discrimination according to destination4.1 The records of call durations obtained by the recording apparatus must be related to particular countries ofdestination and, if required, t
9、o the charging areas of the country of destination; the recording apparatus should thereforebe capable of identifying the destination of a call and of associating the measured call duration with this destination.Note For drawing up international accounts (apart from frontier relations) it is not nec
10、essary to know theorigin of the call or the charging zone from which it comes. The differences in shares resulting from different outgoingcharging zones in a given country are kept by that country.4.2 Incoming country constituting a single charging zoneWhere the recording apparatus is connected to a
11、 circuit group carrying only terminal traffic, no discriminationis required. Where, however, a circuit group carries traffic to more than one country, discrimination between thesecountries must be effected from an examination of the international code for the country and/or the type of seizingsignal
12、 (terminal or transit) which is sent over the international circuits.4.3 Incoming country consisting of several charging zonesIf the accounting procedure agreed between two countries demands the production of separate records of calldurations for calls made to each charging zone in an incoming count
13、ry, the recording apparatus must be arranged todiscriminate between the calls to the different charging zones according to the first one or first two digits of the calledstations national (significant) number2)(see Recommendation E.163).4.4 Special frontier arrangementsTo take account of the special
14、 system of charging for frontier relations (reduced charges between neighbouringfrontier zones), special steps will have to be taken to discriminate between automatic calls in frontier relations andother automatic calls. This discrimination will be made every time that frontier traffic is routed who
15、lly or partly(overflow) by long-distance international circuits having devices for measuring call duration.This discrimination will in general necessitate:a) further analysis of the national (significant) number of the called subscriber than the one which is quoted inRecommendation E.163, andb) the
16、determination of the origin of the call, since frontier charges depend on the distance between theoutgoing and the incoming frontier zones.5 Discrimination according to route and destinationIn general there will be little difficulty in determining the route taken by a call on leaving the outgoingint
17、ernational exchange. If the recording apparatus is connected to the international circuits, then of course therecordings obtained will be appropriate to the route in question. If, however, the recording apparatus is connected to apoint in the exchange remote from the outgoing circuits and the call t
18、o a particular country has the choice of more thanone route, then information in respect of the actual route taken by the call must be supplied to the recording apparatus.6 Distribution of traffic in an international exchange for the purpose of measuring call durationsBy way of example, Figure 1/E.2
19、60 is given hereafter showing how traffic should be distributed in aninternational exchange so as to take account of the provisions above._2)See the definition of the national (significant) number in Recommendation E.160.Fascicle II.2 - Rec. E.260 3The traffic passing through the international excha
20、nge is divided into the following four groups, as shown onthe figure:i) international transit traffic;ii) automatic traffic (originated locally);iii) semiautomatic traffic (originated locally);iv) combined automatic and semiautomatic traffic from provincial exchanges.These groups would employ indepe
21、ndent groups of link circuits and registers. Only group ii) and possiblygroup iv) would be involved in measuring call duration.4 Fascicle II.2 - Rec. E.260The following auxiliary equipment is envisaged:a) for each link circuit in groups ii) and iv), a selecting device capable of dealing with every p
22、ossiblecombination of route/country or charging zone destination;b) for each link circuit in group iv), a device to take care of the discrimination between semiautomatic andautomatic traffic;c) for registers in groups ii) and iv), equipment for analyzing country codes and if necessary an appropriate
23、number of digits of the national (significant) number of the called subscriber in order to discriminatebetween charging zones (see Recommendation E.163, 1.2);d) for registers in group iv), a device to recognize the discriminating digit 0 used for automatic working;e) a means of recording the call duration for each combination of route/country or charging zone destination.References1 CCITT Recommendation New system for accounting in international telephony, Rec. D.150, 4.1.4.2 CCITT Recommendation Language digit or discrimination digit, Rec. Q.104, 1.4.2.
