Tzvo-Niimber Toll Operating Method 



For transmission reasons it was found desirable in large metropolitan 

 areas to provide a separate trunk plant and a separate toll switchboard 

 for handling calls between widely separated central offices. This 

 separate office became known as the "two-number" office and the 

 traffic was handled by the "two-number" method. This method was 

 used for a number of years before the present tandem systems came 

 into service. 



Under the two-number operating method the subscriber gave the 

 called number to his local operator as on a local call. The local oper- 

 ator, over a trunk to the two-number board, passed the called number 

 and then the calling number to the two-number operator. The two- 

 number operator then obtained connection to the calling number over 

 another trunk which afforded better transmission than that of the first 

 trunk, and disconnected from the trunk over which the call was re- 

 ceived. This disconnection caused a signal to light before the local 

 operator who originally received the call, whereupon the local operator 

 took down the connection she had made between the calling party and 

 the two-number operator. The two-number operator then proceeded 

 to establish connection with the called telephone over a trunk of proper 

 transmission design by whatever trunking method was in use. At 

 the time the two-number toll operating method was in greatest use, 

 the usual trunking method was call-circuit although much of this 

 business was handled by the ringdown method. Tickets were written, 

 connections timed, and routes and rates were obtained in much the 

 same manner that they are obtained with the A board toll operating 

 method. The two-number method acquired its name through the 

 fact that the local operator passed two numbers on each call to the so- 

 called two-number operator. 



Two-Ticket Toll Operating Method 



For that portion of the toll business on which the customer reaches 

 and gives his call to the long distance operator, three important toll 

 operating methods have been used. One of the important early toll 

 operating methods involved the writing of a ticket by the operators 

 at both ends of the connection and became known as the "two- 

 ticket" method. 



In each long distance office where the two-ticket operating method 

 was in use, there was provided a recording board at which long distance 

 calls were recorded by a special group of recording operators; there 

 was an arrangement for sending the tickets either by mechanical 

 device or by messenger from the recording board to other positions as 



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