[计] automatic electronic switching center

zì dòng diàn zǐ jiāo huàn zhōng xīn ㄗˋ ㄉㄨㄥˋ ㄉㄧㄢˋ ㄗˇ ㄐㄧㄠ ㄏㄨㄢˋ ㄓㄨㄥ ㄒㄧㄣ