 |
Photo img2_013 |
Computers used to run server applications in a computer center;
these computer provide network disk storage and other client-server
applications.
|
 |
Figure 3.2 |
Illustration of the API calls used for a trivial interaction. The
client sends one request and receives one reply.
|
|
|
Figure 3.5 |
Illustration of the echo application, which can be used on any two
computers connected to the Internet. The client program
runs on one computer and the server program runs on another.
|
|
|
Figure 28.1 |
A client and server using TCP/IP protocols to communicate across an
internet. The client and server each interact with a protocol in the
transport layer.
|
|
|
Figure 28.2 |
Two servers on a single computer accessed by clients on two other
computers. Client 1 can access server 1, while client 2
accesses server 2.
|
|
|
Figure 30.1 |
The sequence of socket procedure calls in the example client and
server. The server must call listen before a client calls
connect.
|
|
|
Figure 32.3 |
The path of an e-mail message. The mail transfer program on the
sender's computer becomes a client of the remote mail server.
|
|
|
Figure 32.4 |
An example SMTP transfer between a client on computer
example.com and a server on computer foobar.com. Each line is
labeled to show whether the client or server transmits the line.
|
|
|
Figure 32.6 |
The path of a message as it passes from a sender's interface through
a mail gateway. On the gateway computer, an exploder handles incoming
e-mail, and a conventional mail transfer program sends a copy to each
recipient.
|
|
|
Figure 32.7 |
The path of e-mail when POP is used to access a mailbox. The mail can
arrive from the sender's computer or a mail gateway. To retrieve messages
from the mailbox, a user runs a program that becomes a client of the POP
server.
|
|
|
Figure 34.2 |
TCP connections between an FTP client and server during a file
transfer, with an arrow showing the direction in which each connection
was formed. Although the control connection remains open, the data
connection is closed after the transfer completes.
|
|
|
Figure 35.4 |
Example HTTP header returned by a server. The
status code 200 on the first line indicates that the server
honored the request; additional lines give further information
about the requested item.
|
|
|
Figure 35.5 |
Major components of a Web browser. Dark arrows show the flow of
data; other arrows show control paths. The data paths from clients to
interpreters are not shown.
|
|
|
Figure 38.2 |
The example program from Figure 38.1 divided into a client
and a server.
|
 |
Data file 2 |
Anonymous FTP session with dir, get
and put. Contains approximately 930Kbytes and 2300
packets.
|
|
|
Data file 3 |
Anonymous FTP session using mput in
both ascii and binary modes. Contains approximately
33Kbytes and 340 packets.
|
|
|
Data file 4 |
Anonymous FTP session using mget in both
ascii and binary modes. Contains approximately
37Kbytes and 370 packets.
|
|
|
Data file 5 |
TELNET session (headers only). Contains approximately
45Kbytes and 560 packets.
|
|
|
Data file 6 |
SMTP session with delivery of one mail message from
SMTP client to SMTP server. Contains approximately 3,000 bytes and 30
packets.
|
|
|
Data file 7 |
WWW browser session accessing multiple URLs from
multiple WWW servers. Contains approximately 590Kbytes and 1,270
packets.
|
|
|
Data file 8 |
X Window System application protocol messages from
several clients, including xterm, emacs,
xspread and xpaint to an X server. Contains
approximately 760Kbytes and 5,500 packets.
|
|
|
Code file 30_1 |
Code sample for client in section 30.6
|
|
|
Code file 30_2 |
Code sample for server in section 30.7
|
