Just plug it into a phone jack and you're ready to go.  I personally tested this phone-  calls and takes calls perfectly-  great vintage ring.  

Description:  Vintage Bell System Rotary Telephone.  BEIGE/TAN desk top style!    Has a volume dial on the headset.  Date on back sticker indicates it was from October 1979. Overall good clean condition with minor wear and occasional scratching along dial and headset from normal use.   Some slight residue where phone number is typed.  A great retro collectible!!