TANDEM OPERATION IN THE BELL SYSTEM 



401 



TABLE II 

 Relative Theoretical Speed of Operation of Tandem Systems 



* On calls handled by operators, this is the interval from receipt of signal at the 

 switchboard to the first ring on the called line. The interval from receiver off hook at 

 the calling station to receipt of signal, is approximately .5 second for manual stations, 

 3 seconds for step-by-step dial stations, and 7 seconds for panel dial stations. Both 

 of the latter include the dialing by the customer of the "Operator" code. 



t In panel areas. 



j When completed to local multiple in toll board at called office. 



