11/13/2013
Chapter 7
1. A user of a home telephone picks up her phone and makes a telephone call to a friend’s home telephone in another part of town. Which of the following is likely to be true about this call?
A. It uses a single pair of wires on the local loop at each end of the call
2. Which of the following are services that telcos have offered as WAN services over the years?
A. Switched analog circuits
B. Dedicated digital circuits
3. This chapter claims that IP routers work well as devices that connect to many different types of interfaces, including LANs and WANs. Which of the following answers list the reasons why routers do well in this role?
A. Routers have much faster CPUs and can do the hard work to translate the incoming datalink header into the outgoing data-link format
D. Routers discard old data-link headers and insert new data-link headers as part of their logic, which treats each interfaces lower-layer detailds as independent from each other
4. An enterprise network has many routers that connect to both a LAN as well as the WAN. Which of the following statements best describe how routers typically use and think about their WAN connections?
B. As a transport service to deliver IP packets to the next Ip router
5. An enterprise builds a WAN design on paper. The main site, where all the servers sit, is shown in the center of a network diagram. The WAN has a leased line from that site to every remote site, with the remote sites drawn around the edges of the drawing in a big circle. None of the remote sites have a leased line directly between them. Which of the following terms is most typically used to describe this WAN topology?
D. Hub-and-spoke
6. A U.S.-based company wants to order a leased line between two sites, with the leased line using the traditional T-carrier DS0, DS1, and DS3 types of lines. Which of the following answers describes the speed and distances for the leased line?
A. No faster than 43,736 Mbps (T3)
D.