II. Rules for establishing and terminating communication sessions

Читайте также:

Application level performance is typically higher in networks with _____ latency and _____ bandwidth.

(a) high, low

(b) high, high

(d) low, high

Item-level feedback: See section 1.1.3, subsection "Basic Network Performance Metrics," in the course notes.

Multicast communication generally refers to data that is

(a) sent from several hosts to one host simultaneously

(b) relayed through multiple routers

(d) sent from one host to several hosts simultaneously

Item-level feedback: See section 1.1.3, subsection "Other Application Metrics," in the course notes.

Socket-level programming typically involves

(a) programming hardware

(b) registries and interface definitions for exchanging data

(d) explicit send and receive calls to exchange data

Item-level feedback: See section 1.1.2 in the course notes.

The Internet Protocol (IP) defines the _____ layer of the Internet protocol stack.

(a) application

(b) transport

(d) network

Item-level feedback: See section 1.1.4, subsection "What Makes the Internet Work?" in the course notes.

The term packetization refers to the process of

(a) reassembling network packets for consumption by an application

(b) using a digital instead of an analog transmission medium

(d) splitting a message into fragments for network transmission

Item-level feedback: See section 1.1.1, subsection "How Application Messages Are Transmitted," in the course notes.

6. Which of the following statements is (are) true of network protocols?

I. A protocol is a set of rules that facilitate communication among network applications.

II. Only a single protocol may govern any transmission.

(a) II only

(b) I and II

(d) I only

Item-level feedback: See section 1.1.1, subsection "Web Browsers and Servers: Network Applications," in the course notes.

7. Typically, a network protocol specifies which of the following?

I. A message format

II. Rules for establishing and terminating communication sessions

(a) I only

(b) II only

(d) I and II

Item-level feedback: See section 1.1.1, subsection "Web Browsers and Servers: Network Application," in the course notes.

8. Which of the following is a protocol used for communication between a web server and a web browser?

(a) FTP

(b) Telnet

(d) HTTP

Item-level feedback: See section 1.1.1, subsection "Other Applications," in the course notes.

9. Which of the following is a disadvantage of connection-based protocols?

(a) Unreliable connections

(b) High error rates

(d) High startup costs

Item-level feedback: See section 1.1.1, subsection "How Application Messages Are Transmitted," in the course notes.

10. On a network, the term authentication typically refers to the process of

(a) ensuring that users remain anonymous

(b) ensuring that packets sent through the Internet cannot be intercepted

(d) verifying the identity of a sender or receiver

Item-level feedback: See section 1.1.3, subsection "Other Application Metrics," in the course notes.

11. Which of the following is the network-layer protocol of the Internet?

(a) HTTP

(b) Telnet

(d) IP

Item-level feedback: See section 1.1.4, subsection "What Makes the Internet Work," in the course notes.

12. In which of the following types of routing algorithms does every router maintain information about the complete network topology?

I.Link state

II.Distance Vector

(a) II only

(b) I and II

(d) I only

Item-level feedback: See section 1.3.2, subsection "Basic Routing Protocols and Algorithms," in the course notes.

13. Which of the following types of traffic occur in intra-domain routing?

I. Local

II. Transit

III. External

(a) I and II only

(b) I and III only

(d) I, II, and III

Item-level feedback: See section 1.3.2, subsection "Hierarchical Routing," in the course notes.

14. The process of setting up routers to exchange connectivity information with each other is called

(a) transit mapping

(b) reverse path forwarding

(d) Peering

Item-level feedback: See section 1.3.2, subsection "Routing in the Real World," in the course notes.

15. Which of the following was designed to solve the problem of IP address space fragmentation?

(a) Maximum Transfer Unit

(b) Simple Network Management Protocol

(d) Classless Inter Domain Routing

Item-level feedback: See section 1.3.3, subsection "Classless Inter Domain Routing," in the course notes.

16. Which of the following IP header fields provide simple error detection?

(a) Fragmentation

(b) Time to live

(d) Checksum

Item-level feedback: See section 1.3.4, subsection "Internet Protocol Functionality," in the course notes.

17. Which of the following maps IP addresses onto datalink addresses?

(a) Domain Name System (DNS)

(b) Simple Network Management Protocol (SNMP)

(d) Address Resolution Protocol (ARP)

Item-level feedback: See section 1.3.5, subsection "Summary," in the course notes.

18. Consider an application running on host cs.cmu.edu that wants to send a packet to host ee.cmu.edu. Assuming no information is cached, the send request on cs.cmu.edu will cause which of the following events to happen first?

(a) An ARP lookup

(b) The packet is sent to the first router.

(d) A DNS lookup

Item-level feedback: See section 1.3.5, subsection "Example," in the course notes.

19. Which of the following can be used by a router to report a dropped packet to the packet's sender?

(a) Simple Network Management Protocol (SNMP)

(b) Border Gateway Protocol (BGP)

(d) Internet Control Message Protocol (ICMP)

Item-level feedback: See section 1.3.6, subsection "Internet Control Message Protocol," in the course notes.

20. Which of the following is typically used to monitor the operation of network routers and switches?

(a) Internet Control Message Protocol (ICMP)

(b) Border Gateway Protocol (BGP)

(d) Simple Network Management Protocol (SNMP)

Item-level feedback: See section 1.3.6, subsection "Network Management," in the course notes.

21. Which of the following IP header fields is designed to prevent a packet from remaining indefinitely in a routing loop?

(a) Checksum

(b) Length

(d) Time to live

Item-level feedback: See section 1.3.4, subsection "Internet Protocol Functionality," in the course notes.

22. Which of the following allows a host to be assigned an IP address automatically?

(a) The simple network management protocol (SNMP)

(b) The domain name system (DNS)

(d) The dynamic host configuration protocol (DHCP)

Item-level feedback: See section 1.3.6, subsection "Host Configuration," in the course notes.

23. Which of the following network exploration tools can be used to determine information about possible paths between one network host and another?

(a) Ping

(b) Netstat

(d) Traceroute

Item-level feedback: See section 1.3.7, subsection "Traceroute," in the course notes.

24. Forcing a packet to be routed through specific network routers by appending an additional header to the packet is commonly known as

(a) forwarding

(b) encapsulation

(d) tunneling

25. The throughput of a transmission medium is limited by which of the following factors?

I. The width of the available frequency spectrum

II. The effects of noise and attenuation

III. The number of encoding levels in the signal

(a) I only

(b) II and III only

(d) I, II, and III

Item-level feedback: See section 1.2.1, subsection "Transmission," in the course notes.

26. Compared to the wired transmission, wireless transmission typically has _____ attenuation and _____ maximum distance.

(a) higher, longer

(b) lower, shorter

(d) higher, shorter

Item-level feedback: See section 1.2.1, subsection "Transmission," in the course notes.

27. If the datalink layer uses special start characters and end characters to mark the boundary of a frame, these special characters must be _____ inside the frame.

(a) repeated

(b) synchronized

(d) escaped

Item-level feedback: See section 1.2.2, subsection "Framing," in the course notes.

28. Which of the following features of Ethernet has not remained constant since the advent of the technology?

(a) Protocol header format

(b) Protocol addressing

(d) Transmission bandwidth

Item-level feedback: See section 1.2.4, subsection "The Ethernet Family," in the course notes.

29. A Digital Subscriber Line (DSL) is a _____ network that uses a _____ topology.

(a) broadcast-based, star

(b) broadcast-based, ring

(d) switch-based, star

Item-level feedback: See section 1.2.5, subsection "Home Connectivity Over the Years," in the course notes.

30. Which of the following is offered by both Serial Line IP (SLIP) and Point-to-Point Protocol (PPP)?

(a) Reliable transmission

(b) Authentication

(d) Flow control

Item-level feedback: See section 1.2.5, subsection "Datalink Protocols," in the course notes.

31. In cell-based wireless networks, the MAC protocol inside the cells is typically

(a) switch-based

(b) packet-based

(d) broadcast-based

Item-level feedback: See section 1.2.6, subsection "Wireless cells," in the course notes.

32. Which of the following is (are) true of local area wireless networks?

I. They are typically based on cells using point-to-point media links.

II. Two wireless hosts can be within transmission range of the base station but out of range of each other.

III. They have higher roundtrip delays than similar wired networks.

(a) I only

(b) I and III only

(d) II only

Item-level feedback: See section 1.2.6, subsection "Local, Metropolitan, and Wide Area Wireless Communication," in the course notes.

33. User Datagram Protocol (UDP) uses which of the following for optional error detection?

(a) Odd parity check

(b) Message-digest fingerprint

(d) One's complement sum

Item-level feedback: See section 2.1.2, subsection "User Datagram Protocol (UDP)," in the course notes.

34. Which of the following internet applications typically transmit(s) packets over Transmission Control Protocol (TCP)?

I. FTP client

II. Audio streaming

III. Web browser

(a) I, II, and III

(b) II only

(d) I and III only

Item-level feedback: See section 2.1.2, subsection "User Datagram Protocol (UDP) and 2.1.3#Transmission Control Protocol (TCP)," in the course notes.

35. Which of the following transport protocol functions is (are) typically implemented for audio streaming?

I. End-to-end flow control

II. Error control

III. Congestion control

(a) II and III only

(b) I, II, and III

(d) II only

Item-level feedback: See section 2.1.5, subsection "An Example: Audio Streaming," in the course notes.

36. Consider the transport protocols for audio streaming applications. Which of the following is used to improve the quality of audio output with variable network delays?

(a) Random packet dropping

(b) Forward error correction

(d) Silent period adjustment

Item-level feedback: See section 2.1.5, subsection "An Example: Audio Streaming," in the course notes.

37. In Transmission Control Protocol (TCP), network traffic sources can dynamically increase transfer rate over time by

(a) sniffing

(b) buffering

(d) probing

Item-level feedback: See section 2.1.4, subsection "Congestion Control: Open-Loop and Closed-Loop," in the course notes.

38. In order to maintain network stability while Transmission Control Protocol (TCP) probes for additional bandwidth, rate increases are _____, and rate decreases are _____.

(a) multiplicative, additive

(b) additive, additive

(d) additive, multiplicative

Item-level feedback: See section 2.1.4, subsection "Congestion Control: Open-Loop and Closed-Loop," in the course notes.

39. Network clients use well-known _____ numbers to contact well-defined network services, such as Telnet and DNS servers.

(a) accept

(b) connect

(d) port

Item-level feedback: See section 2.2.1, subsection "Establishing connections," in the course notes.

40. Which of the following is a standard that a network program can use to specify the type of a transmitted document?

(a) Internet Assigned Numbers Authority (IANA)

(b) Transmission Control Protocol (TCP)

(d) Multipurpose Internet Mail Extensions (MIME)

Item-level feedback: See section 2.2.2, subsection "MIME," in the course notes.

41. Which of the following distributed-computing frameworks represents client-server interactions as simple function invocations?

(a) Transmission Control Protocol (TCP)

(b) Multipurpose Internet Mail Extensions (MIME)

(d) Remote Procedure Call (RPC)

Item-level feedback: See section 2.2.3, subsection "Motivation," in the course notes.

42. In video-streaming applications, per-frame compression exploits _____ redundancy in the data, whereas inter-frame compression exploits _____ redundancy in the data.

(a) temporal, spatial

(b) visual, auditory

(d) spatial, temporal

Item-level feedback: See section 2.2.4, subsection "Application Properties, 2.2.4#Application Properties," in the course notes.

43. A client program that makes a remote procedure call (RPC) uses a call to a(n) _____ instead of contacting the RPC server directly.

(a) skeleton routine

(b) RMI server

(d) stub routine

Item-level feedback: See section 2.2.3, subsection "Analysis of an RPC," in the course notes.

44. In a remote procedure call (RPC) framework, the _____ is responsible for converting typed parameters into byte strings that can be transmitted over a network.

(a) client programmer

(b) RPC server

(d) stub routine

Item-level feedback: See section 2.2.3, subsection "Analysis of an RPC," in the course notes.

45. In network Quality of Service (QoS), which of the following does the traditional best-effort Internet service model guarantee?

I. Packet delivery

II. Latency limit

III. Bandwidth

(a) I and II only

(b) II and III only

(d) None

Item-level feedback: See section 2.3.1, subsection "Beyond The "Best Effort" Service Model," in the course notes.

46. In an integrated services model, which of the following is (are) necessary in order to provide network Quality of Service (QoS) guarantees?

I. Admission control

II. Traffic enforcement

(a) I only

(b) II only

(d) I and II

Item-level feedback: See section 2.3.1, subsection "Toward An Integrated Services Model," in the course notes.

47. In an integrated services network, in order to offer Quality of Service (QoS), a packet classifier is required to

(a) determine the source and destination port numbers

(b) determine the source and destination IP address

(d) identify the type of the flow to which the packet belongs

Item-level feedback: See section 2.3.1, subsection "Toward An Integrated Services Model," in the course notes.

48. In an integrated services network, it is necessary to have a traffic enforcement mechanism to ensure that

(a) the bandwidth shared among organizations is divided equally

(b) each router is handling a reasonable workload

(d) applications do not exceed their agreed transmission rate

Item-level feedback: See section 2.3.1, subsection "Toward An Integrated Services Model," in the course notes.

49. Traditional First-In First-Out (FIFO) packet schedulers are insufficient for offering Quality of Service (QoS) guarantees in an integrated services network because the schedulers typically

(a) give audio and video packets high priority

(b) use different buffers to store packets for different users

(d) treat all packets with the same priority

Item-level feedback: See section 2.3.2, subsection "Fair Queuing Packet Scheduling," in the course notes.

50. In Quality of Service (QoS) networks, a fair queuing (FQ) scheduler typically consists of a _____ and a(n) _____.

(a) real-time scheduler, static dispatcher

(b) packet dispatcher, real-time classifier

(d) packet classifier, actual scheduler

Item-level feedback: See section 2.3.2, subsection "Fair Queuing Packet Scheduling," in the course notes.

51. In Quality of Service (QoS) networks, using a weighted fair queuing (WFQ) scheduler is a typical way to support

(a) network monitoring

(b) packet classification

(d) bandwidth reservation

Item-level feedback: See section 2.3.2, subsection "Weighted Fair Queuing," in the course notes.

52. Which of the following is (are) true about Quality of Service (QoS) networks?

I. The complexity of routers is less than in other kinds of networks.

II. Routers must maintain more state information than in other kinds of networks.

(a) I and II

(b) I only

(d) II only 100%

Item-level feedback: See section 2.3.2, subsection "Discussion," in the course notes.

53. In the IETF Integrated Services (IntServ) model, which of the following is (are) available to an application that uses the guaranteed service class?

I. A packet latency guarantee

II. A bandwidth guarantee

(a) I only

(b) II only

(d) I and II

Item-level feedback: See section 2.3.3, subsection "The Integrated Services Model," in the course notes.

54. Compared to the IETF Integrated Services (IntServ) model, which of the following is a unique goal of the Differentiated Services (DiffServ) model?

(a) Maximum application support

(b) Minimum packet delay

(d) Maximum scalability

Item-level feedback: See section 2.3.3, subsection "The Differentiated Services Model," in the course notes.

55. Which of the following is (are) used by distributed computer systems to synchronize clocks?

I. Network Time Protocol (NTP)

II. Global Positioning System (GPS)

(a) I only

(b) II only

(d) I and II

Item-level feedback: See section 3.1.2, subsection "Logical vs. Physical Clocks," in the course notes.

56. Which of the following approximates a global physical clock that uses the happens-before partial order?

(a) Local clock

(b) Global Positioning System (GPS) clock

(d) Logical clock

Item-level feedback: See section 3.1.2, subsection "Logical vs. Physical Clocks," in the course notes.

57. Which of the following types of events in a distributed system can typically be ordered arbitrarily?

(a) Logical

(b) Physical

(d) Disjoint

Item-level feedback: See section 3.1.2, subsection "Logical vs. Physical Clocks," in the course notes.

58. In a distributed system, which of the following would best tolerate a Byzantine failure?

(a) Backups

(b) Checkpoints

(d) Mirroring with voting

Item-level feedback: See section 3.1.3, subsection "Improving fault tolerance," in the course notes.

59. Which of the following is (are) true about distributed file systems?

I. Files and directories are stored on network servers.

II. Distributed file systems typically support fine-grained sharing.

III. Distributed file systems typically use communicating protocols such as Remote Procedure Call (RPC).

(a) II only

(b) I and II only

(d) I and III only

Item-level feedback: See section 3.1.4, subsection "Overview," in the course notes.

60. Distributed applications often manage inter-process communication though _____, a method that uses a logically shared address space.

(a) message passing

(b) distributed file systems

(d) distributed shared memory

Item-level feedback: See section 3.1.4, subsection "Overview," in the course notes.

61. Some distributed file systems allow multiple copies of files due to caching. Which of the following types of distributed file servers leave(s) the resolution of file consistency issues up to the users?

I. Stateless

II. Stateful

(a) II only

(b) I and II

(d) I only

Item-level feedback: See section 3.1.4, subsection "Consistency," in the course notes.

62. Which of the following security threats is not typically addressed by encryption?

(a) Snooping

(b) Message modification

(d) Denial of Service

Item-level feedback: See section 3.1.5, subsection "Denial of Service Attacks," in the course notes.

63. Which of the following protocols requires the transmission of a user's password or private key across the network?

I. Kerberos

II. Secure Socket Layer (SSL)

(a) I only

(b) I and II

(d) None

Item-level feedback: See section 3.1.6, subsection "Kerberos, 3.1.6#Secure Socket Layer," in the course notes.

64. Which of the following can be used for user authentication?

I. Kerberos

II. Secure Socket Layer (SSL)

(a) I only

(b) II only

(d) I and II

Item-level feedback: See section 3.1.6, subsection "Kerberos, 3.1.6#Secure Socket Layer," in the course notes.

65. Consider a client/server setup in which the client must access data that is stored on the server. A Remote Procedure Call (RPC) is typically suitable for accessing data with which of the following characteristics?

I. The data is too large to transfer to the client.

II. The data is real-time streaming audio.

III. The data is sensitive from a security standpoint.

(a) II only

(b) II and III only

(d) I and III only