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  | PART  | OF DIGITAL SWITCH  | |||||
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  | DATA  | TERMINAL  | 
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  | TN726  | 
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  | EQUIPMENT,  | 
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  | DATA  | LINE  | CP  | 
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  | HOST  | COMPUTER  | 
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  | Z3A1/2/4  | 
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  | ADU  | 
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  | TN742  | 
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  | VOICE  | TERMINAL  | 
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  | ANALOG  | LINE  | 
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  | OR  | 
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  | CP OR  | 
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  | ZTN78  | TIP  | 
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  | 7101A)  | 
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  | RING  | LINE  | CP  | 
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  | DATA  | TERMINAL  | 
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  | TN726  | 
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  | EQUIPMENT,  | 
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  | DATA  | LINE  | CP  | 
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  | HOST  | COMPUTER  | 
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  | Z3A5  | 
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  | ADU  | 
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  | MULTILINE  | 
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  | ZTN79  | 
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  | VOICE  | TERMINAL  | 
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  | ATL LINE  | CP  | 
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  | TIME  | 
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  | ZTN76  | 
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  | DIVISION  | 
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  | GROUND  | START  | 
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  | MULTIPLEX  | 
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  | CO, FX, WATS  | 
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  | TRUNK  | CP  | 
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  | BUS  | 
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  | — — — — —  | 
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  | O R  | 
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  | PAGING  | 
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  | ZTN77  | 
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  | EQUIPMENT  | 
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  | LOOP  | START  | 
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  | TRUNK  | CP  | 
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  | TN753  | 
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  | DID  | TRUNKS  | 
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  | DID  | 
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  | TRUNK  | CP  | 
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  | TN760B  | 
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  | TIE  | TRUNKS  | 
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  | TIE  | 
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  | TRUNK CP  | 
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  | LEGEND  | :  | 
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  | 
  | A D U –  | ASYNCHRONOUS DATA | UNIT | 
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  | ||||||||
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  | CAS | –  | CALL ACCOUNTING | SYSTEM | 
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  | CO  | –  | CENTRAL  | OFFICE  | 
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  | |||
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  | CP –  | CIRCUIT  | PACK  | 
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  | DID - DIRECT  | INWARD DIALING  | 
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  | ||||||||
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  | D T U– DIGITAL TAPE UNIT  | 
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  | FX –  | FOREIGN  | EXCHANGE  | 
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  | ||||
  | 
  | MET – MULTIBUTTON ELECTRONIC TELEPHONE  | 
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  | ||||||||||||
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  | O P S-   | 
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  | SAT – SYSTEM ADMINISTRATION TERMINAL  | 
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  | ||||||||||||
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  | S M D R– STATION MESSAGE DETAIL RECORDING  | 
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  | ||||||||||||
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  | WATS - WIDE AREA TELECOMMUNICATIONS SERVICE  | 
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  | ||||||||||||