A.物理層 B.網(wǎng)絡(luò)層 C.傳輸層 D.接入層 E.分發(fā)層 F.數(shù)據(jù)鏈路層
A.2B+D B.30B+D C.同軸電纜 D.普通電纜
A.dialer time ridle B.dialer time rcompete C.dialer time renable D.dialer time rwait-carrier