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Figure 17.1 |
Two physical networks connected by a router, which has a separate interface for each network connection. Computers can attach to each network. |
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Figure 17.2 |
An internet formed by using three routers to interconnect four physical networks. Each network can be a LAN or a WAN. |
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Figure 17.3 |
The internet concept. (a) The illusion of a single network that TCP/IP software provides to users and applications, and (b) the underlying physical structure in which a computer attaches to one physical network, and routers interconnect the networks. |
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Figure 17.4 |
The five layers of the TCP/IP reference model. |
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Animation 17_1 |
In an internet, the protocol software on the source computer constructs an IP datagram and transmits it to a router by encapsulating the datagram in a hardware frame. The router extracts the datagram and retransmits it in a new hardware frame to the next router on the path to the destination; the destination extracts the original datagram from the last hardware frame and delivers the data to the application. |
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Data file 1 |
Trace of all IP traffic on Ethernet segment. Contains approximately 87,000 packets and 6.5Mb. Trace includes packet headers only. |
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Data file 2 |
Anonymous FTP session with dir, get and put. Contains approximately 930Kbytes and 2300 packets. |
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Data file 3 |
Anonymous FTP session using mput in both ascii and binary modes. Contains approximately 33Kbytes and 340 packets. |
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Data file 4 |
Anonymous FTP session using mget in both ascii and binary modes. Contains approximately 37Kbytes and 370 packets. |
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Data file 5 |
TELNET session (headers only). Contains approximately 45Kbytes and 560 packets. |
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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. |
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Data file 7 |
WWW browser session accessing multiple URLs from multiple WWW servers. Contains approximately 590Kbytes and 1,270 packets. |
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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. |
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Photo 6_019 |
A 24-port 10/100 Mbps Ethernet interface board for a Cisco Catalyst 5000 switch. The circuitry at the left of the photo handles the transmission and reception of Ethernet frames. The circuitry at the right communicates with the rest of the Catalyst 5000 switch. The circuitry in the middle of the board performs the frame switching function. |
