双向（建立呼叫）

both-way channel【通信】;two-way channel【通信】

both-way communication【通信】;two-directional communication【通信】;two-way communication【通信】

both-way communication

both-way line【电子】

both-way trunk line

both-way operation

both-way trunk line【通信】;two-way trunk line【通信】

both-way line