A.B碼對(duì)時(shí) B.SNTP對(duì)時(shí) C.IEEE1588對(duì)時(shí) D.鐘表對(duì)時(shí)
A.GMRP協(xié)議 B.以太網(wǎng) C.單播 D.廣播
A.單播 B.優(yōu)先級(jí) C.排隊(duì) D.廣播