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?（）

A. Encapsulates several different types of routing protocols.
B. Supports only IP.
C. Can be used over analog circuits.
D. Is proprietary to Cisco
E. Supports error correction.

多项选择题What are some common layer 2 encapsulations for a WAN link?（）

A. Ethernet
B. PPP
C. Token Ring
D. HDLC
E. Frame Relay
F. POTS

单项选择题Which WAN service utilizes two different encapsulation types (one for data and one for signaling) on its data link layer?（）

A. ISDN
B. Frame Relay
C. ATM
D. FDDI

单项选择题A router receives a packet on interface 172.16.45.66 26. The source IP of the packet is 172.16.45.127 26 and the destination is 172.16.46.191 26.How will the router handle the packet?（）

A. The destination is a host on another subnet, so the router will not forward the packet.
B. The destination is a host on the same subnet, so the router will forward the packet.
C. The destination is a broadcast address, so the router will not forward the packet.
D. The destination is a network address, so the router will forward the packet.

单项选择题Network equipment supporting the use of flow control mechanisms has been recently installed. What is the purpose of flow control in a data network?（）

A. It ensures that data is retransmitted if an acknowledgment is not received.
B. It reassembles segments in the correct order on the destination device.
C. It provides a mechanism for the receiver to control the transmission speed.
D. It regulates the size of each datagram segment.
E. All of the above are functions of flow control