AUTOMATIC TESTING OF INTERTOLL TRUNKS 



933 



Fig. 3 — Automatic intertoll trunk testing equipment. 



circuit, sometimes referred to as "far end equipment," is associated 

 with the group of code 104 test lines for performing the transmission 

 measurements. When simultaneous transmission test calls arrive in the 

 distant office from different originating offices, the calls wait on the 

 code 104 test lines and are served by the transmission measuring and 

 noise checking circuit, one at a time, in their proper turn. 



After the trunk test frame has obtained a path through the switching 

 train in the originating office to the trunk to be tested as explained 

 above, it pulses forward over the trunk the desired test line code, either 

 code 103 or code 104. In response to the code, the switching equipment 

 in the distant office sets up a path through the switching train to one of 



