当被叫手机无法开通的情况，被叫可设置关机彩铃，如开会，上课，睡觉等等。而主叫拨通被叫手机，判断被叫是否关机，如果关机，则播放提前预设的关机彩铃，这样主叫也可知道被叫因为什么原因而关机。-When the called phone can not open the case, called ring tones can be set off, such as meetings, classes, sleep and so on. The caller dials the called phone, called to determine whether the shutdown, if the shutdown, the shutdown is the default ring tones play early, so called because the caller can know what the shutdown.