Chapter Review Questions

You can find the answers to the following questions in Appendix A, "Answers to Chapter Review Questions."

1:	How many twisted pairs of wires are typically used in a leased line between two routers?
2:	Imagine that you wanted to create a WAN link between two routers (Router A and Router B) in cities that are 1000 miles apart. How long are the cables that the telco needs to run?
3:	What is a WAN link?
4:	What are some of the other names for a WAN link?
5:	Explain whether point-to-point WAN links need something like the Ethernet CSMA/CD algorithm.
6:	What kind of physical interface does a router use to connect to a WAN link?
7:	Imagine that a WAN link has been installed between routers A and B. The physical cable from the telco was plugged directly into the serial interfaces on the routers. What feature must be included in the serial interface cards on these routers to allow the cable to be connected directly to the routers?
8:	What is the main function of the CSU/DSU, as covered in this chapter?
9:	What is the base transmission speed typically used for WAN links that run at relatively lower speeds (up to 1.5 Mbps)?
10:	What are the two most popular data link protocols used on WAN links?
11:	What does HDLC do to alert a router that is receiving a frame that an error has occurred?
12:	Of the two more popular WAN link data link protocols, which was developed later and has more features?
13:	Explain whether IP ARP is needed on WAN links. Why or why not?