单项选择题
Which ISDN device converts the four-wire BRI signals from an S/T interface into two-wire signals of a U interface?（）
A.TE1 B.NT-2 C.TA D.TE2 E.NT-1
单项选择题 Which WAN protocol is used for out-of-band signaling?（）
单项选择题 Inverse ARP is being used in the TestKing frame relay network. What is the purpose of Inverse ARP?（）
多项选择题 WAN data link encapsulation types include which of the following?（）
