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.