Recommendation U.7
                             NUMBERING SCHEMES FOR AUTOMATIC SWITCHING NETWORKS
                           (former CCIT Recommendation E.7, Geneva, 1956)
               The CCITT,
         considering
               that with fully automatic working between subscribers in the  international
         telex service it is desirable to envisage the possibility:
               a)  of routing traffic over the appropriate international trunk route where
         more than one such route exists between two countries;
               b)  of enabling the appropriate tariff to be determined  automatically  (in
         the originating country), even if the destination country is divided into several
         tariff zones,
         unanimously declares the view
               (1) that subscribers' national numbering  plans  should  be  systematically
         arranged;
               (2) that, where more than one international trunk route exist  between  two
         countries, the corresponding geographical  division  and  hence  the  appropriate
         point of entry should be identifiable by examination of the initial digits of the
         called subscriber's national number;
               (3) that, where a multiple tariff scale exists, the different tariff  zones
         should be identifiable in the originating country by the initial  digits  of  the
         called subscriber's national number;
               (4) that the number of initial digits to be  examined  should  be  limited,
         preferably to one, but in any case should not exceed two.  When  a  single  digit
         provides the discrimination it will usually be the first digit,  but,  where  the
         subscribers' national numbers have a uniform initial digit (usually 0) to  permit
         discrimination on internal calls, the following (second) digit should be used.
               Note - The attention of Administrations (and recognized  private  operating
         agencies) is drawn to the considerable technical advantage that would result from
         the adoption of a single tariff between two countries.







































                                                         Fascicle VII.2 - Rec. U.7   PAGE1