In this mode, the information is carried in frame format, using either high-level data link control (HDLC) or PPP as the Layer 2 protocol.是什么意思_In this mode, the information is carried in frame format, using either high-level data link control (HDLC) or PPP as the Layer 2 protocol.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句