The LAPD-like frames are transported as packet streams in a wideband packet network over a full or fractional primary channel, or an SDH virtual tributary.是什么意思_The LAPD-like frames are transported as packet streams in a wideband packet network over a full or fractional primary channel, or an SDH virtual tributary.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句