In China people usually say "wei" (hello) first when beginning a telephone conversation. If bạn call an old acquaintance and recognize his/her voice, bạn may address him/her directly bởi name. Otherwise, bạn have to make clear who the other person is bởi saying, "Hello! Excuse me. Are bạn so-and-so?" hoặc "Hello! Are bạn so-and-so?" instead of saying "I an so-and-so" first. "So-and-so" may be name of a person hoặc a company.
--Wèi, shì lǐ míng ma?
(Hello! Are bạn Li Ming?)
--Duì, shì wǒ. Nǐ shì Qí Qí ma?
(Yes, I am Li Ming. bạn are Qi Qi, aren't you?)
One usually says, "You...