1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 such offices are described as linked offices. In the case of a particular telegram, the linked officethrough which the telegram enters the system is known as the linked entry office; the linked office through which thetelegram leaves the system is known a
2、s the linked exit office.(c) The present Recommendation has been drawn up for fully automatic working, but may be used for semi-automatic and manual working.(d) To facilitate world-wide operation of the telegram retransmission system, to simplify the transfer oftelegrams between the retransmission n
3、etwork and other networks and to enable the switching and accountingequipment needed for the retransmission centres to be designed, the CCITT,unanimously declares that1 Each telegram must be treated independently, even if several telegrams for the same destination arrive in seriesat a linked entry o
4、ffice.2 The format to be used in preparing the telegram for transmission shall be as follows:2.1 The heading of the telegram shall start with the numbering line preceded by a carriage-return, a line-feed and aletter-shift. The numbering line consists of:2.1.1 The start-of-message signal (SOM)In acco
5、rdance with Recommendation F.30 the start-of-message signal (SOM) is made up by the sequence ofcombinations Nos. 26, 3, 26, 3 of International Telegraph Alphabet No. 2 (ZCZC) followed by:2.1.2 The channel sequence numberTelegrams transmitted over a channel shall be numbered according to a series of
6、numbers for each channel.The channel sequence number will therefore be composed of three letters characteristic of the channel used (channelindicator) followed by a number showing the order of this telegram in the series sent over this channel. The channelsequence numbers shall be in sequence from 0
7、01 to 999 and change automatically from 999 to 001 at the end of anumbering cycle.When the telegram passes from one channel to another in a network, each new channel sequence number shallbe inserted immediately after the start-of-message signal. The channel sequence numbers will appear in the number
8、ingline of the telegram in the opposite order to that in which the telegram passed through the network.The channel sequence number shall be transmitted as: space; three letters constituting the channel indicator; figure-shift; three figures constituting the number in the series on the channel.Servic
9、e advices will be numbered in the channel series unless agreed otherwise by the Administrationsconcerned. The channel sequence number(s) is followed by:2 Fascicle II.4 - Rec. F.312.1.3 The telegram identification group (TIG)The telegram identification group enables the office of origin to recognize
10、the telegram. This group must notexceed 15 printing characters, which may be composed of any combination of letters and/or figures. In the special caseof a telegram from the gentex network to the telegram retransmission system, the telegram identification group will bethe only reference in the numbe
11、ring line and will consist of two letters identifying the originating country or aparticular network therein (in accordance with Recommendation F.96), the call number of the gentex office followedby one or two letters identifying the gentex position and the serial number of the telegram which that p
12、osition sends.The telegram identification group shall be transmitted as: space; letter-shift (if necessary); not more than 15 printing characters;followed by:2.1.4 End of line carriage-return; line-feed;which will mark the end of the numbering line, followed by:2.2 The second line of the heading, th
13、e pilot line, which consists of:2.2.1 The destination indicatorThis indicator is extracted from the List of Destination Indicators and Telex Network Identification Codes 1,and consists of four letters; the first two characterize the destination country (or a particular network in the destinationcoun
14、try) and the following two letters characterize an office of that country (see also 4 below).The destination indicator shall be transmitted as: letter-shift; four letters;followed by:2.2.2 The priority and tariff indicatorThis indicator consists of two letters chosen in such a way that the priority
15、letters of the indicator differ fromeach other by at least two unit elements and the same letter does not appear twice in the same indicator, thus reducingthe possibilities of error.2.2.2.1 The first letter will designate the priority of transmission according to the following table:A Telegrams rela
16、ting to safety of life (SVH)B Telegrams relating to the application of the United Nations Charter (ETATPRIORITE) Government telegrams with priority (ETATPRIORITE) Meteorological telegrams (OBS) Ordinary private telegrams with urgent transmission and delivery (URGENT) RCT telegrams with urgent transm
17、ission and delivery (URGENT RCT) Money orders and postal cheque telegrams with urgent transmission and delivery (URGENTPOSTFIN)C Government telegrams (ETAT) Service telegrams (A) Service advices (A)Fascicle II.4 - Rec. F.31 3 Ordinary private telegrams RCT telegrams (RCT) Money orders and postal che
18、que telegrams (POSTFIN) TelemessageH Letter telegrams (including government letter telegrams) (LT, LTF)This table takes account of the order of transmission given in Recommmendation F.1, A136 to A144.2.2.2.2 A telegram that has been abnormally delayed can be upgraded to a higher priority group. Such
19、 promotion canbe effected only in the linked entry office; in this case, a category H telegram could be marked C and a category Ctelegram marked B, but a telegram with lower priority than A can never be promoted to category A.2.2.2.3 The second letter will designate the tariff class to be used accor
20、ding to the following table:F Radiotelegrams routed via a foreign land station;J2POSTFIN telegrams1);K Government telegrams where preferential rate is to be charged;L Letter telegrams;M Meteorological telegrams;N Non-chargeable telegrams;O Ordinary private telegrams;Q2Telegrams involving special acc
21、ounting features1);R RCT telegrams;T TelemessagesU Telegrams (other than RCT telegrams) with urgent transmission and delivery;V2Divided telegrams 1);X For use by transit offices when inserting the pilot line on transit telegrams;Y Government full-rate telegrams;Z Government letter-rate telegrams.2.2
22、.2.4 Letters D, E, G, I, P, S and W are available for assignment when required.2)The priority and tariff indicator shall be transmitted as: space; two letters;followed by:2.2.3 The origin indicatorThe origin indicator consists of four letters; the first two will be the same as those used in the dest
23、inationindicators for the originating Administration or network; the third and fourth will represent:a) a particular city or town within that country or network; orb) the office or department to which service correspondence regarding the telegram should be addressed._1)Where there is a choice tariff
24、 indicator the one marked with a 2takes precedence.2)Administrations may agree mutually to accept additional tariff indicators.4 Fascicle II.4 - Rec. F.31Administrations may select the last two letters to satisfy the requirements of their internal organization butwhere there is more than one entry p
25、oint to a country or network from any station the choice of letter combinationsmust be negotiated with that station where they differ from the destination indicator for the office in question.Administrations that take advantage of this facility should notify the CCITT of the origin indicators in use
26、 in theirsystem.The origin indicator shall be transmitted as: space; four letters;followed by:2.2.4 The number of chargeable wordsThe number of chargeable words shall be transmitted in the form of a three-figure number (for example 009)using the number of chargeable words shown in the preamble line
27、for the telegram in question. For a non-chargeabletelegram the number 000 will be shown.The number of chargeable words shall be transmitted as: space; figure-shift; three figures;followed by:2.2.5 A customer identification group (optional): This group characterizes the customer for accounting purpos
28、es andcan be composed of any combination of letters and/or figures. It will not be transmitted beyond the first retransmissioncentre. (See also Recommendation F.1 C108.)The customer identification group shall be transmitted as: space; the customer identification group;followed by:2.2.6 End of line c
29、arriage-return; line-feed;which will mark the end of the second line (pilot line), followed by:2.3 The third line of the heading which is the preamble line and which shall be transmitted as shown inRecommendation F.1, A140 to A144, including any service instructions, followed by: carriage-return; th
30、ree line-feeds;followed by:2.4 The address part3)2.4.1 The service indication line (where required)Any service indications should be placed on a separate line immediately before the address. Each indicationshall be transmitted as one word. If there are several indications each will be separated by a
31、 space.The service indication line is transmitted as: letter-shift (if necessary);_3)For postal addresses, the address part (including service indication line) should be composed of a maximum of six linespreferably not exceding 30 printing/ spacing characters. An address part of five lines of up to
32、43 printing/spacingcharacters each be accepted.Fascicle II.4 - Rec. F.31 5 the service indications; carriage-return; line-feed;followed by:2.4.2 The address linesThe address of a telegram shall be transmitted as: letter-shift (if necessary); the address; the name of the office of destination isolate
33、d in the last line (see Recommendation F.1, A39 to A100); carriage-return; three line-feeds;followed by:2.5 The text part2.5.1 The text shall be transmitted as: letter-shift (if necessary); text; carriage-return; line-feed or ten line-feeds(if signature present) (if no signature present).2.5.2 The s
34、ignature shall be transmitted as: minimum five spaces; signature; carriage-return; ten line-feeds.2.6 The end-of-message signal (EOM)In accordance with Recommendation F.30 the end-of-message signal (EOM) shall be transmitted as: letter-shift; NNNN; ten letter-shifts (except where not required).2.7 F
35、ormat examplesAnnex A gives an example of the format of a typical ordinary private telegram showing all the functionalsignals. Formats of other telegrams will be found in Recommendation F.1.3 Choice of destination indicator3.1 The linked entry office of the telegram retransmission network selects th
36、e destination indicator to be entered inthe pilot line of a telegram.3.2 Apart from the exceptions given in 4.3, 4.4 and 4.5 the destination indicator shall be selected from the Listof Destination Indicators and Telex Network Identification Codes 1 (see Recommendation F.96) according to therules in
37、Table l/F.31.3.3 Administrations wishing to do so may use the destination indicator all others (or one of the all othersindicators) of the country of the office concerned for the telegrams to an office appearing in the List of Indicators 1,but not directly connected to the telegram retransmission ne
38、twork.6 Fascicle II.4 - Rec. F.313.4 By private agreement between the Administrations concerned, the destination indicator to be used for eachtown of a country may be selected from any of the destination indicators for the country according to the internalrouting of the country.3.5 For return servic
39、e advices, etc., relating to a telegram, the destination indicator shall be the origin indicatorgiven in the telegram.4 Routing4.1 Within a telegram retransmission centre, a telegram shall be directed to the following channel in the chain ofconnections by the destination indicator shown on the pilot
40、 line of the telegram, in accordance with the trafficcirculation scheme of the telegram retransmission centre.4.2 If the appropriate subsequent route for the telegram is not connected with the telegram retransmissionequipment, the destination indicator shall direct the telegram to a place in the cen
41、tre where it can be handled andreforwarded.TABLE 1/F.31Rules for selecting the destination indicatorABCA single network indestination countrySeveral networks in destination countryTelegramshowing routingTelegramnot showing routing1. Destination towndirectly connected withtelegram retransmissionsyste
42、m, or to which adestination indicator isallocatedUse destination indicatorgiven in the List againstthe town concernedUse destination indicatorwith the two letters for thenetxork in the Listfollowed by the two lettersfor the town in the ListUse destination indicatorwith the two letters forunrouted fo
43、r the countryconcerned followed by thetwo letters for the town inthe List2. Other destinations Use destination indicatorall others given in the Listfor destination countryUse destination indicatorwith the two letters for thentwork in the List,followed by the two letterscorresponding to all othersfor
44、 the country concernedUse destination indicatorwith the two letters forunrouted for the countryconcerned, followed by twoletters for all others for thecountry5 Tolerances as to the format and checking of format5.1 Switching equipment shall tolerate:a) a space and letter-shift transposition or a spac
45、e and figure-shift transposition in a sequence normallyprescribed as having to be a space followed by a shift;b) the repetition of a function signal, except for the space between the destination indicator and the priorityindicator;c) the reception of characters between successive end-of-message sign
46、als and start-of-message signals (forexample: spurious signals, letter-shifts or other functional signals) without affecting the proper functioningof the equipment. (Any transmission from the sending end of a channel between an end-of-message signaland the subsequent start-of-message signal should b
47、e limited to those characters that have a function at thereceiving end of the channel.)5.2 If a repetition or a transposition in the sequence carriage-return, line-feed, letter-shift separating the numberingline from the pilot line cannot be tolerated by the switching equipment, the telegram affecte
48、d by such a defect will bedirected towards a manual service position.Fascicle II.4 - Rec. F.31 75.3 Any deviation from the format that might be recognized by a centre and that goes beyond the acceptabletolerances as given herein shall as far as possible be corrected before retransmission to another
49、switching centre.5.4 If the operator in preparing a telegram detects an error in the set-up of the numbering line or the pilot line, hemust destroy the part already set up and start preparation of his telegram again. But if the transmission of these twolines has already started, the operator shall send the code expression ANUL space ANUL followed by ten line-feedsand the end-of-message signal. Any telegram so terminated shall not, if possible, be retransmitted by the firstswitching equipme
