Interoffice trunking and signaling

EACH ENGINEER who for the first time concerns himself with the problems of telephone interoffice trunking discovers that practically the only source of information regarding equipment and operation comes from actual circuits and circuit description sheets which are not always available. This paper summarizes the information gained from a review of a number of trunk circuits with a view to providing the interested engineer with a basis for choosing the method of operation best suited to his particular need.