These are especially data concerning the state of the line or trunk or tie-line dial information and classes of service of the line, trunk or tie-line ... signalling procedure for the free or busy state of the station and for an initiating signal for starting answer-back and manual call transfer. ... In the case of the III W 6030 it is a very simple pircuit, which consists on the central office side in essential of a ringing-toneanbsp;...
|Title||:||International Switching Symposium record|
|Author||:||IEEE Communications Society|