CROSSBAR TANDEM AS A TOLL SWITCHING SYSTEM 



95 



office balance and by the use of impedance compensators and fixed pads. 

 A well balanced two-wire switching system, proper assignment of inter- 

 toll trunk losses, and the use of carrier circuits with high speed of propa- 

 gation will permit through switching Mdth little or no impairment from 

 an echo standpoint. 



The new features for crossbar tandem will provide arrangements 

 necessary for operation at control switching points (CSP's). These in- 

 clude automatic alternate routing, the ability to store and send forward 



TP 



e 



I I NC = NATIONAL CENTER 

 RC = REGIONAL CENTER 

 /\ SC = SECTIONAL CENTER 

 ( J PC = PRIMARY CENTER 



Fig. 2 — Homing arrangement for local central offices and toll centers. 



TC = TOLL CENTER 

 TP = TOLL POINT 

 EG = END OFFICE 



