SSD8Multiple-Choice选择题答案

1. Which of the following parameters can be specified in the header of a request in the Hypertext

Transfer Protocol (HTTP)?

The types of image formats that a browser understands

The type of browser (e.g., Netscape, Internet Explorer) making the request

The method by which the request is to be satisfied—for example, whether the request is a GET of

a form submission

(a) III only

(b) I, II, and III

2. Which of the following distinguish stream sockets (e.g., TCP) from datagram sockets (e.g.,

UDP)?

Stream sockets guarantee delivery of the data sent through them.

Stream sockets can be used to send application data to a remote host, whereas datagram sockets

can only send control commands.

Stream sockets have greater overhead.

(a) I and III only

(b) I and II only

(c) II and III only

(d) I only

network is

(a) not able to be determined with the information given

(b) exactly 10 Kbps

(c) in the range from 60 to 120 Kbps (kilobits per second)

(d) in the range from 6 to 12 Kbps (kilobits per second)

Correct answer is (c)

Feedback:

See section 1.1.4 of the course notes.

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4. An application on a computer sends data through a socket to another computer. Which of the

The header format, which specifies the header field sizes and meanings

(a) II and III only

(b) III only

(c) I only

(d) I and III only

Correct answer is (b)

Feedback:

See section 1.1.1 of the course notes.

(d) a protocol designed by committee always has better performance than that designed by a

single company or research project

Correct answer is (a)

Feedback:

See section 1.1.1 of the course notes.

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6. We send a packet from host A to host B, which immediately acknowledges it. We measure the

interval between the time the packet is sent by A and its acknowledgement is received. This

interval is found to be 180 milliseconds. What can be said about the latency of the link from A to

B?

See section 1.1.4 of the course notes.

(d) This would be so only if the latency in the direction A->B was identical to the latency in the

direction B->A

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7. What can be said about the protocol used by the implementation of the transport layer of an

It guarantees delivery.

It is the Transmission Control Protocol (TCP).

It uses services provided by the session layer.

(a) none

(b) I only

Feedback:

See section 1.1.5 of the course notes.

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8. Which of the following methods are invoked by a client implemented with sockets?

I. connect ( )

II.listen ( )

III. read ( )

(a) I, II, and III

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9. When you connect your computer to the Internet, the protocol(s) your computer uses is (are)

selected according to

(a) the application client and server you use at each moment

(b) which HTTP (Web) server you connect to

(c) which operating system is running on your computer

(d) what vendor your Internet service provider purchased equipment from

Correct answer is (a)

Feedback:

See section 1.1.1 of the course notes.

(b) I only

(c) I and II only

(d) III only

Correct answer is (c)

Feedback:

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2. Packet collisions occur in an Ethernet network because

(a) the Ethernet switching mechanism may occasionally send two packets through the same route

(b) two different Ethernet networks may be spliced together

(c) two Ethernet nodes can send packets at the same time

Feedback:

See section 1.1.2 of the course notes.

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3. The Maximum Transfer Unit (MTU) is a parameter of

(a) the technology of the physical network

(b) the application protocol

(c) the size of data sent by the application

(d) the operating system

(a) in the order A-B, after possibly having traversed different routes

(b) in the order A-B, after having traversed the same route

(c) in any order, after having traversed the same route

(d) in any order, after possibly having traversed different routes

Correct answer is (d)

Feedback:

See section 1.1.2 of the course notes.

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5. Ethernet (IEEE 802.3) is an example of

(a) a successful example of the Internet's strategy of developing standards through "rough

See section 1.1.6 of the course notes.

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6. In a broadcast network

(a) only the destination computer sees a packet

(b) only the computers that are tuned to a channel see and process the packets in that channel

(d) all computers see all packets, but the application data in each packet is only processed by the

destination computer

Correct answer is (d)

Feedback:

See section 1.1.1 of the course notes.

difficult because today's Internet

(a) gives higher priority to bulk data transfers

(b) is unable to guarantee minimum throughput or maximum latency for a given connection

(c) does not really have sufficient throughput

(d) uses connectionless protocols

Correct answer is (b)

Feedback:

See section 1.1.4 of the course notes.

It uses services provided by the session layer.

(a) none

(b) I and II only

(c) I only

(d) II only

Correct answer is (d)

Feedback:

See section 1.1.5 of the course notes.

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10. Why do network applications send "messages," but the network transmits information in

(a) II and IV only

(b) II and III only

(c) I and II only

(d) I, II, III, and IV

Correct answer is (c)

See section 1.1.1 of the course notes.

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2. The Protocol Data Unit (PDU) that is sent by a protocol layer to its peer on the destination

system typically includes

A payload