Wide Area Networks Answers Part 2

12. In ______ geometric layout for a network, every computer is connected to every other computer often by point-to-point dedicated circuits. a. b. c. d. e. full mesh design ring design star design bus design partial mesh design Answer: a 13. Mesh networks: a. usually provide relatively long routes through the network (compared to ring networks) b. typically contain more circuits in the network than in star or ring networks c. do not use decentralized routing d. typically are less expensive than ring networks e. do not have many possible routes through the network to prevent one circuit from becoming overloaded Answer: b 14. _____ are dedicated digital circuits that are the most commonly used form of dedicated circuit services in North America today. a. b. c. d. e. Wideband analog services SMDS ATM T-carrier services ISDN Answer: d 15. The data rate for a T-1 circuit in North America is: a. b. c. d. e. 1.544 Mbps 6.312 Mbps 44.376 Mbps 274.176 Mbps 1.544 Gbps Answer: a 16. In North America, a T1 circuit has ______ 64Kbps channels. a. b. c. d. e. 2 30 24 12 36 Answer: c 17. The data rate for a T-3 circuit in North America is: a. b. c. d. e. 1.544 Mbps 6.312 Mbps 44.376 Mbps 274.176 Mbps 1.544 Gbps Answer: c 18. SONET: a. is a standard for optical transmission that currently operates at Terabit per second speeds b. is almost identical to the ITU-T standard, synchronous digital hierarchy (SDH) c. uses existing copper cabling and the PSTN network d. refers to Sprint Overall Network e. is not currently available, even in large cities Answer: b 19. Which of the following is not a benefit of packet switched services? a. The data transmission rates tend to be lower than dial-up or dedicated circuits. b. You do not have to set up dedicated circuits between each endpoint from which you wish to transmit and receive data and/or voice. c. You have the flexibility to send data through a temporary circuit between two connections that will be disconnected as soon as the digital transmission is completed. d. All circuits are less susceptible to a great deal of noise because they are digital. e. You do not have to specify all the interconnecting services you need for your WAN when you buy the service. Answer: a 20. A _____________ is a user’s connection into a packet switched service. a. b. c. d. e. packet analog/digital device packet asynchronous/discrete device packet asymmetric/data transmission device packet assembly/disassembly device packet analyzer/decoder device Answer: d 21. Which of the following type of networks permit packets from separate messages to be interleaved? a. b. c. d. e. circuit switched network dedicated circuit network dial up circuit network packet switched network Fractional T-1 network Answer: d 22. A _______ is a connectionless method of sending data packets on a packet switched service. a. b. c. d. e. bursty packet virtual circuit datagram histogram permanent virtual circuit Answer: c 23. A _________ is a connection-oriented approach to sending packets on a packet switched service. a. b. c. d. e. permanent virtual circuit datagram histogram bursty packet fractional T-1 network Answer: a 24. In a packet switched network, permanent virtual circuits that look very similar to a _____________ (for hardware-based dedicated circuits) move packets through the network. a. b. c. d. e. cloud-based ring design cloak-based mesh design cloud-based mesh design common carrier ring design common carrier bus design Answer: c 25. ______________ are sometimes called private line services. a. b. c. d. e. WANs LANs Circuit-switched networks Dedicated-circuit networks Routed-backbone networks Answer: d 26. OC-3072 has a data rate of a. b. c. d. e. 159.25 Gbps 39.813 Gbps 1.544 Mbps 100 Mbps 1.244 Gbps Answer: a 27. _____________ is sometimes called a Layer 2.5 technology. a. b. c. d. e. ATM MPLS Ethernet TCP IP Answer: b 28. Ethernet/IP packet networks: a. b. c. d. e. are supported with gigabit fiber optic networks in large cities are offered only by the common carriers use token ring layer 2 media access control use IPX/SPX protocols provide CIR up to a maximum of 1.544 Mbps Answer: a 29. A _______________ is a particular type of network that uses circuits that run over the Internet but that appears to the user to be a private network. a. b. c. d. e. local carrier network virtual private network integrated service digital network software defined network SONET network Answer: b 30. With a virtual private network, users create permanent virtual circuits through the Internet called: a. b. c. d. e. bursts cells tunnels rings clouds Answer: c 31. Which of the following is a primary advantage of a VPN in comparison to a private WAN connection? a. b. c. d. e. low cost inflexibility unpredictable traffic congestion security complexity to the user Answer: a 32. _____________ is a common standard for use by layer 2 access VPNs for encapsulation. a. b. c. d. e. L2TP VPN2 Encapsule2 TCP/IP PPP Answer: a 33. Which of the following is not a type of VPN? a. b. c. d. e. intranet VPN extranet VPN access VPN T-1 VPN a VPN that enables employees to access an organization’s network from a remote location Answer: d 34. __________ is a term that refers to the time delay in converting input packets to output packets. a. b. c. d. e. Transfer mode Latency Burstiness Cell relay Frame relay Answer: b 35. The performance of WANs can be improved by: a. b. c. d. e. upgrading the circuits between the computers increasing the demand placed on the network downgrading the circuits between the computers downgrading the devices that provide access to the circuits increasing network traffic Answer: a 36. Dynamic routing: a. b. c. d. imposes an overhead cost by increasing network traffic decreases performance in networks which have many possible routes decreases performance in networks with “bursty” traffic does not add to the network traffic and should be used in all network environments e. is another term for static routing in WANs Answer: a 37. Which of the following is not a way to reduce network demand? a. shifting network usage from high cost times to lower cost times b. using data compression techniques for all data in the network c. requiring a network impact statement for all application software developed by the organization d. moving data further from the applications and people who use them e. shifting network usage from peak to lower demand times Answer: d 38. Which of the following is not a key issue to be considered when selecting a WAN service? a. b. c. d. e. prestige value of using a particular common carrier flexibility capacity control reliability Answer: a 39. Which WAN technology is designed to work with a variety of commonly used layer2 protocols and is sometimes called a layer-2.5 technology because it inserts a 4-byte header that contains its own information between the layer-2 frame and the layer-3 IP packet? a. b. c. d. e. Ethernet TCP MPLS IRoute T1 Answer: c 40. Which of the following is not a type of WAN services that is used to connect company offices to each other or to cloud providers. a. b. c. d. Dedicated-circuit services TCP Packet-switched services Virtual private network Answer: b 41. A Software Defined WAN (SDWAN) provides four benefits. Which of the following is not one of those benefits? a. b. c. d. e: Centralized management Lower cost More visibility over network traffic Good security Flexibility Answer: e 42. The architecture of an SDWAN has three parts, which are also called planes. Which of the following is not one of those planes? a. b. c. d. Management plane Control plane Encryption plane Data plane Answer: c