Chapter 10 Carrier Wide Area Networks (WANs)
1) A network that runs on the customer premises is a ________. A) LAN B) WAN C) both A and B D) neither A nor B
Answer: A
25) For ADSL service, which of the following typically must be added to the telephone system? A) a DSLAM B) a transmission line to the customer premises C) both A and B D) neither A nor B
Answer: A
26) The promise of FTTH is ________. A) higher speed B) lower cost C) both A and B D) neither A nor B
Answer: A
27) Fiber to the home service is normally created by ________. A) running optical fiber to neighborhoods B) running individual fiber cords from the nearest switching building to individual homes C) both A and B D) neither A nor B
Answer: A
3) A WAN is the network that ________. A) links different sites together B) provides service within about a mile C) provides service within a site D) all of the above
Answer: A
31) Compared to ADSL service, cable modem service typically is ________. A) faster and more expensive B) faster and less expensive C) slower and more expensive D) slower and less expensive
Answer: A
33) In cellular technology, a ________ is a small geographical area. A) cell B) cellsite C) both A and B D) neither A nor B
Answer: A
36) Cells are used in cellular telephony to provide ________. A) service for more customers B) greater reliability C) greater transmission speed D) all of the above
Answer: A
37) Today's dominant cellular technology is ________. A) LTE B) 3G C) HSPA+ D) MTSO
Answer: A
4) Companies use carriers for WAN transmission because ________. A) companies lack rights of way B) carriers have extremely strong security C) both A and B D) neither A nor B
Answer: A
40) Leased lines offer ________ service. A) fast B) any-to-any C) rapid-connection D) none of the above
Answer: A
41) Which lines run from one customer premise to another? A) leased lines B) access lines C) both A and B D) neither A nor B
Answer: A
43) A customer's leased line to its ISP connects to the ISP's ________. A) POP B) NAP C) CSU/DSU D) interface
Answer: A
46) Many "T1" lines that carriers provide today use ________ in the local loop. A) 1-pair voice-grade UTP B) 2-pair voice-grade UTP C) 1-pair data-grade UTP D) 2-pair data-grade UTP
Answer: A
5) A company has more control over its ________ technology. A) LAN B) WAN
Answer: A
52) In Carrier Ethernet, which service is a competitor for leased line service? A) E-Line B) E-LAN C) both A and B D) neither A nor B
Answer: A
55) MPLS ________ the work that each router must do to deliver a packet during a traffic exchange. A) reduces B) increases C) does not affect D) occasionally reduces
Answer: A
59) MPLS is ________ the source and destination hosts. A) transparent to B) nontransparent to C) apparent to D) a burden on
Answer: A
61) WAN optimization devices are deployed ________. A) at the ends of leased lines B) by the telephone carrier C) by the PSDN carrier D) by the ISP
Answer: A
63) In caching, ________. A) a message may not have to be transmitted B) messages are cached at the transmitting end of the line C) both A and B D) neither A nor B
Answer: A
68) Control functions are located in routers in ________. A) traditional routing B) SDN C) both A and B D) neither A nor B
Answer: A
70) SDN ________. A) reduces CapEx B) increases OPEx C) both A and B D) neither A nor B
Answer: A
71) In SDN, a switch receives its forwarding table rules directly from ________. A) the SDN controller B) an SDN management application C) another switch D) an SNMP manager
Answer: A
73) Communication between SDN applications and SDN controllers is governed by ________. A) northbound APIs B) southbound APIs C) both A and B D) neither A nor B
Answer: A
8) Which of the following usually offers higher speeds? A) LANs B) WANs C) Both A and B are about equal in typical speeds.
Answer: A
11) The Internet is a ________. A) LAN B) WAN C) both A and B D) neither A nor B
Answer: B
12) Which of the following does the carrier NOT own? A) the network core B) customer premises equipment C) both A and B D) neither A nor B
Answer: B
14) Which of the following allows you to connect to the hosts of almost any corporation today? A) carrier WANs B) the Internet C) both A and B
Answer: B
15) How do WAN carriers typically get their trunk lines? A) They construct them. B) They lease them from telephone companies. C) They use wireless transmission. D) They use the Internet.
Answer: B
20) DSL residential service provides ________. A) symmetric speed B) asymmetric speed C) both A and B D) neither A nor
Answer: B
22) Which of the following already runs to nearly all customer premises? A) 4-pair UTP B) 1-pair VG UTP C) 1-pair DG UTP D) none of the above
Answer: B
24) In ADSL, the residential customer needs a(n) ________. A) DSLAM B) ADSL modem C) both A and B D) neither A nor B
Answer: B
30) Two-way amplifiers are needed for cable ________ service. A) television B) data C) both A and B D) neither A nor B
Answer: B
34) In cellular technology, the carrier antenna and equipment to which mobile customers connect directly is called a(n) ________. A) cell B) cellsite C) MTSO D) wireline carrier
Answer: B
44) T1 leased lines run at a speed of about ________. A) 250 kbps B) 1 Mbps C) 10 Mbps D) 45 Mbps
Answer: B
45) To connect two sites at 2.8 Mbps, I would use ________. A) a T1 line B) bonded T1 lines C) a T2 line D) a T3 line
Answer: B
47) Which of the following DSL services tends to be symmetric in speed? A) residential B) business C) both A and B D) neither A nor B
Answer: B
48) Which of the following DSL services usually offers QoS guarantees? A) residential B) business C) both A and B D) neither A nor B
Answer: B
51) The PSDN technology that is growing rapidly today is ________. A) Frame Relay B) Carrier Ethernet C) the Internet D) No PSDN technology is growing rapidly today.
Answer: B
54) In MPLS, the router interface to send the packet back out will be decided ________. A) during the router's routing process B) before the packet arrives C) by a dynamic routing protocol D) none of the above
Answer: B
57) In MPLS, the ________ adds the label to the packet. A) source host B) first label-switching router C) both A and B D) neither A nor B
Answer: B
58) MPLS routers base their decisions on a packet's ________. A) destination IP address B) label number C) both A and B D) neither A nor B
Answer: B
66) The creation of routing tables for a router is an example of ________. A) forwarding B) control C) both A and B D) neither A nor B
Answer: B
7) Which of the following has more diversity in technologies? A) LANs B) WANs C) Both A and B are about equal in diversity of technologies.
Answer: B
72) A router's load-balancing process is determined by ________. A) the SDN controller B) an SDN application C) the router D) any of the above
Answer: B
74) OpenFlow can be used to standardize ________. A) northbound APIs B) southbound APIs C) both A and B D) neither A nor B
Answer: B
10) WANs are ________. A) single networks B) internets C) either A or B D) neither A nor B
Answer: C
13) Which of the following is a common use for carrier WANs? A) to connect corporate sites B) to connect a corporate site to the Internet C) both A and B D) neither A nor B
Answer: C
18) The PSTN core is organized as a ________. A) mesh B) hierarchy C) modified hierarchy D) loop
Answer: C
19) DSL offers ________. A) voice transmission B) data transmission C) both A and B D) neither A nor B
Answer: C
2) A LAN is the network that ________. A) links different sites together B) provides service within a company C) provides service within a site D) all of the above
Answer: C
21) What transmission medium do ALL DSL services use? A) one-pair data-grade UTP B) two-pair data-grade UTP C) one-pair voice-grade UTP D) all of the above
Answer: C
23) In ADSL, the customer should have ________. A) splitters B) an ADSL modem C) both A and B D) neither A nor B
Answer: C
28) For their transmission medium, cable television companies primarily use ________. A) 2-pair VG UTP cabling B) 2-pair DG UTP cabling C) coaxial cable D) 4-pair UTP
Answer: C
32) Which of the following is moving toward FTTH? A) cable modem service companies B) ADSL service companies C) both A and B D) neither A nor B
Answer: C
35) An MTSO ________. A) controls cellsites in a cellular system B) links mobile users to wired telephone customers C) both A and B D) neither A nor B
Answer: C
38) What speed does the LTE Advanced standard require downstream? A) 3 Mbps B) 30 Mbps C) 3 Gbps D) 30 Gbps
Answer: C
39) Which of the following affects what throughput an individual user will receive? A) being in a moving car B) being far from the cellsite C) both A and B D) neither A nor B
Answer: C
42) To use a leased line, the customer requires a(n) ________ at each site. A) switch B) router C) CSU/DSU D) modem
Answer: C
49) A firm uses a PSDN. It has four sites. How many leased lines will it need? A) 0 B) 1 C) 4 D) none of the above
Answer: C
50) In a PSDN, customers connect to the network core at ________. A) NAPs B) public/private access points C) POPs D) DSLAMs
Answer: C
53) Why is Carrier Ethernet popular? A) It uses a familiar technology. B) It has attractive prices. C) both A and B D) neither A nor B
Answer: C
56) In MPLS, the packet travels along the ________. A) route B) data link C) label-switched path D) MPLS path
Answer: C
62) WAN optimization provides ________. A) network protocol acceleration B) caching C) both A and B D) neither A nor B
Answer: C
64) Traffic shaping ________. A) limits the amount of some types of traffic B) does not admit some types of traffic C) both A and B D) neither A nor B
Answer: C
67) Forwarding functions are located in routers in ________. A) traditional routing B) SDN C) both A and B D) neither A nor B
Answer: C
69) SDN can ________. A) permit routing rules to be changed rapidly B) reduces router costs C) both A and B D) neither A nor B
Answer: C
9) LANs are ________. A) single networks B) local internets C) either A or B D) neither A nor B
Answer: C
16) In the telephone system, the lines that connect customers to the nearest switch are called the ________. A) access lines B) local lines C) access loop D) local loop
Answer: D
17) Most end-office switches are Class ________ switches. A) 1 B) 2 C) 3 D) 5
Answer: D
29) In coaxial cable, the two conductors ________. A) run side-by-side B) are twisted around each other C) both A and B D) neither A nor B
Answer: D
6) LAN speeds are faster than WAN speeds. This is because of ________. A) technological limitations B) regulatory limitations C) slow corporate adoption of newer WAN technologies D) economic reasons
Answer: D
60) Label-switching routers bring ________. A) lower cost B) the ability to do traffic engineering C) quality of service D) all of the above
Answer: D
65) The highest layer in SDN consists of ________. A) switches B) routers C) the SDN controller D) SDN applications
Answer: D
