A.發(fā)送方從下層向上層傳輸數(shù)據(jù),每經(jīng)過一層附加協(xié)議控制信息
B.接收方從下層向上層傳輸數(shù)據(jù),每經(jīng)過一層附加協(xié)議控制信息
C.發(fā)送方從上層向下層傳輸數(shù)據(jù),每經(jīng)過一層附加協(xié)議控制信息
D.接收方從上層向下層傳輸數(shù)據(jù),每經(jīng)過一層附加協(xié)議控制信息
A.物理層
B.網(wǎng)絡(luò)層
C.傳輸層
D.應(yīng)用層