Recommendation U.30
                      SIGNALLING CONDITIONS FOR USE IN THE INTERNATIONAL GENTEX NETWORK
                                         (New Delhi, 1960)
               The CCITT,
         considering
               (a) that the conditions in Recommendation U.1 concerning signalling in  the
         international  telex  service,  the  specifications  in  Recommendation  U.2  for
         standardization of dials and dial pulse generators  in  the  international  telex
         service, in Recommendation U.3 for the reduction of the effect of  false  calling
         signals, and  in  Recommendation  U.5  on  the  characteristics  of  regenerative
         repeaters used in international calls, will hold  good  in  the  gentex  network,
         except those referring specifically to manual or semi-automatic working. In  some
         countries, indeed, no distinction is  made  between  the  gentex  and  the  telex
         networks;
               (b) that the differences between signalling conditions in the telex and the
         gentex networks are essentially due to the possibility of using overflow  in  the
         gentex network, and the absence of charges in it,
         unanimously declares the following view
         1      The recommendations in SS  1  to  12  of  Recommendation  U.1  (Signalling
         conditions to be applied in the international telex service) shall also apply  to
         the gentex network subject to the following changes:
         1.1    Proceed-to-transmit signal (Recommendation U.1, S 5.2)
               The proceed-to-transmit signal is not used in  the  gentex  network,  since
         switching is always automatic.
         1.2    Selection signals
               Recommendation U.1, S 6.3 should read as follows for the gentex network:
               If  there  is  selection  towards  a  system  in  which  selection  is   by
         teleprinter signal, the prepare-for-digits signal will  normally  be  combination
         No. 30 (figure-shift). By agreement between the Administrations  concerned,  this
         combination could be replaced  by  another  combination  for  gentex  calls  over
         circuits used for gentex and telex traffic simultaneously, if the network of  the
         country of arrival can ensure barring between the two kinds of traffic.
         2      Table 1b/U.1 (signal characteristics) applies to the gentex network.
         3      Recommendation U.2 (Standardization of dials and dial pulse generators for
         the international telex service), Recommendation U.3 (Arrangements  in  switching
         equipment to minimize the effects of false calling signals),  and  Recommendation
         U.5  (Requirements  to  be  met  by  regenerative  repeaters   in   international
         connections), apply to the gentex network.































                                                        Fascicle VII.2 - Rec. U.30   PAGE1