Fundamental Plans for Toll Telephone Plant

This paper covers the general switching plan and fundamental plant layout proposed for handling telephone toll messages throughout the United States and Canada using automatic toll switching. There has been rapid growth in the number of telephones and in the volume of toll traffic, particularly long haul. Toll facilities are provided under fundamental plans, an essential part of which is a toll switching plan for setting up connections quickly between any two telephones. The introduction of mechanical operation and the general improvement in the transmission performance of the communication plant over a period of years make the introduction of certain modifications in the fundamental plans possible and advantageous at this time. The important new features and the service improvements which are provided by the proposed plans are outlined in this paper. The principal types and characteristics of circuit facilities available for use in the intertoll network are also described. GENERAL ASPECTS OF TOLL SWITCHING PROBLEMS Switching plans providing for the systematic routing of toll telephone traffic h a v e been employed by the communication industry for m a n y years. These plans have contributed directly to the high quality of long distance telephone service enjoyed by the public in the United States and C a n a d a . This generally excellent service is the result of the cooperative work of m a n y organizations including the Bell Operating Companies, m a n y independent connecting Companies a n d others in t h e United States as well as in adjoining countries.