Chapter 2 - 353

True

A Web cache, or proxy server, is a network entity that satisfies HTTP requests on behalf of an origin Web server

Caching

A _______ server is a computer that, when it receives a DNS reply, temporarily stores the mapping in its local memory.

Pull

A message access protocol is a ________ protocol.

header; body

An e-mail message contains a ________ and a __________.

either UDP or TCP

DNS can use the services of ________.

An ASCII 13 character followed by an ASCII 10 character

Each line in an HTTP request message, before the entity body, is terminated with

True

HTTP uses TCP as its underlying transport layer protocol

True

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

False

In BitTorrent, a peer's instantaneous download rate can never exceed its instantaneous upload rate.

tracker

In BitTorrent, each torrent has an infrastructure node called a ____________

A proxy

In HTTP, _______ server is a network entity that satisfies HTTP requests on the behalf of an origin Web server.

None of the choices are correct

In HTTP, the first line in a request message is called a _______ line; the first line in the response message is called the ________ line.

the server must be running all the time but the client needs to be running only when it is needed.

In a client-server paradigm

Dots

In the domain name space, a full domain name is a sequence of labels separated by ________.

True

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

Chunks

Peers in a torrent download equal-size pieces of a file called

True

SMTP restricts the body of all mail messages to simple 7-bit ASCII

True

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

304 Not Modified

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:

False

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

False

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

protocol

The first section of a URL identifier is the __________.

SMTP

The formal protocol used to transfer messages from senders' mail servers to recipients' mail servers in the Internet is ___________.