A.TCP請求 B.TCP應(yīng)答報文 C.ICMP Echo請求報文 D.ICMP Echo應(yīng)答報文
A.提供對物理層的控制 B.差錯控制 C.流量控制 D.決定傳輸報文的最佳路由
A.Set the encapsulation of the interface to HDLC B.Place the CSU/DSU in local-loop mode C.Enable local-loop mode on the DCE Frame Relay router D.Verify that the encapsulation is set to Frame Relay