noun
Telephone switchboard; the physical equipment used to connect calls manually.
昔のホテルには交換台があった。
Old hotels had a switchboard.
noun
switchboard operator
Colloquial metonymy; the person who operates the switchboard.
交換台に電話をつないでもらった。
I had the switchboard operator connect the call.
Compound of 交換 (switch, exchange) and 台 (stand, platform). The operator sense is a colloquial metonymy.