单项选择题
You are preparing to create a point to point WAN by connecting a Cisco router with a Juniper router by way of their serial links. Which one of the following commands would you use?（）
A. TK1(config-if)# encapsulation hdlc ansi B. TK1(config-if)# encapsulation ppp C. TK1(config-if)# encapsulation LAPD D. TK1(config-if)# encapsulation frame-relay ietf E. TK1(config)#encapsulation ppp
单项选择题 Which one of the WAN data-link protocols below is used for out-of-band signaling?（）
多项选择题 Which of the following correctly describe characteristics of PPP?（）
多项选择题 What are some common layer 2 encapsulations for a WAN link?（）
