There's a phone in Buddy and Seymour's old room that is a private internal line, and it just goes from one room to another in the apartment; it's not an outside phone line.

在巴蒂和西莫的就房间里，有一台电话,有一个私人的内部线路，在公寓里的房间联通,不与外界相连。

耶鲁公开课 - 1945年后的美国小说课程节选