switch·board 
/ˈswɪtʃˌboɚd/ noun
plural switch·boards /ˈswɪtʃˌboɚd/ noun [count] : a system used to connect telephone calls with many separate phone lines in a building
▪ She used to work as a switchboard operator. ▪ Angry callers flooded/jammed the company's switchboard. [=made telephone calls to the company]
▪ She used to work as a switchboard operator. ▪ Angry callers flooded/jammed the company's switchboard. [=made telephone calls to the company]
