Self-Assessment Quizzes Chapter 2 MC，T&F

*1.

The transfer of an html file from one host to another is

none of the above
loss-tolerant and time sensitive
loss-intolerant and time insensitive
loss-intolerant and time sensitive

*2.

A browser will generate header lines as a function of

user configuration of browser
whether the browser has a cached version of the requ- ested bject
browser type and version
all of the above

*3.

Suppose a client sends an HTTP
request message with the If-modified-
since: header.Suppose the object in a
server has not changed since the last
time a client retrieved the object.
Then the server will send a response
message with the status code:

404 Not Found
304 Not Modified
200 OK
none of the above

*4.

Suppose the hit rate is .5 (instead
of .4) in the caching example in the
text. Then the average delay is

between 1.0 and 1.1 seconds
between 1.2 and 1.3 seconds
none of the above
greater than two seconds

*5.

SMTP is used to

to define the format of message headers
to transfer messages from mail server to a user agent
all of the above
to transfer messages from one mail server to another

*6.

Suppose a DNS resource record
has Type=MX. Then

Value is the IP address of the mail server that has the alias hostname Name.
none of the above
Value is the hostname of the DNS server that is authoritative for Name.
Value is the hostname of the mail server that has the alias hostname Name.

*7.

Local DNS name servers

never cache resource records
cache resource records and never discard them
obtain resource records from Web caches
cache resource records, but discard them after a period of time that is on the order of a few days

*8.

Streams are not needed in which
of the following programs:

TCPclient
UDPserver
UDPclient
TCPserver

*9.

Consider the minimum time for
P2P filedistribution, as discussed
in Section 2.6.Suppose the upload
rate of the server is10 Mbps, the
upload rates of all peers is 1 Mbps,
and the download rates of all
peers is 10 Mbps. Further suppose
that there are 100 peers and the
file is 100 million bits. The minimum
distribution time is

approximately 10 seconds
approximately 1000 seconds
approximately 1 second
approximately 100 seconds

*10.

For BitTorrent, which of the
following is true:

Among the chunks that a peer does not have, the peer will request chunks that appear to be relatively rare in the torrent.
Although a peer may have 50 concurrent TCP connections with other peers, at any given instant of time it sends data to less than 10 other peers.
At a given instant of time, a peer A may upload to a peer B, even if peer B is not sending anything to A.
All of the above.

*11.

A server can use cooki-es to
determine a user's postal address
without the user's consent.

True
False

*12.

The Web typically sends multiple
objects in a Web page within a
multipart MIME message.

True
False

*13.

It is possible for a mail client to
send e-mail messages over HTTP
rather than SMTP.

True
False

*14.

If a POP3 client does not send
the dele command, copies of the
messages that the client has retrieved
remain in the mail server.

True
False

*15.

With SMTP, it is possible to send
multiple mail messages over the same
TCP connection.

True
False

*16.

DNS lookups often involve a
combination of recursive and
iterative queries.

True
False

*17.

With non-persistent connections
between browser and origin server,
it is possible for a single TCP segment
to carry two distinct HTTP request messages.

True
False

*18.

The Date: header in the HTTP
response message indicates when
the object in the response was last
modified.

True
False

*19.

In BitTorrent, a peer’s instantan-
eous download rate can never exceed
its instantaneous upload rate.

True
False

*20.

Skype relay nodes are typically
peers under the control of Skype users.

True
False

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