The data link layer provides a service to the network layer.It encapsulates the network layer information in a frame (the Layer 2 PDU).是什么意思_The data link layer provides a service to the network layer.It encapsulates the network layer information in a frame (the Layer 2 PDU).在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句