An ISDN option that alerts a Terminal Adapter (TA) or ISDN-capable router that a second call is coming in over a given Bearer (B) channel.是什么意思_An ISDN option that alerts a Terminal Adapter (TA) or ISDN-capable router that a second call is coming in over a given Bearer (B) channel.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句