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Figure 7.1 |
An illustration of one reason computer networks use packets. While one pair of computers communicate, others must wait. |
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Figure 7.2 |
Illustration of multiplexing with packets. The sources take turns using the shared communication channel. (a) Computer 1 uses the resource to send a packet, and then (b) computer 2 uses the resource to send a packet. |
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Figure 8.11 |
An ATM switch with six computers attached, and the star topology that results. |
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Figure 8.12 |
Details of a connection between an ATM switch and a computer. Each connection consists of a pair of optical fibers. One fiber carries data to the switch, and the other carries data to the computer. |
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Figure 11.1 |
Optical fibers and fiber modems used to provide a connection between a computer and a distant Ethernet. The computer and Ethernet hub both use conventional signals. |
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Figure 11.2 |
A repeater R connecting two Ethernets. The repeater connects directly to the cable. |
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Figure 11.3 |
Repeaters used to connect Ethernet segments on three floors of an office building. Each floor has one segment, and one segment is placed vertically in the building. |
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Figure 11.4 |
Six computers connected to a pair of bridged LAN segments. The bridge, which uses the same type of connection as a computer, always sends and receives complete frames. |
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Figure 11.5 |
A sequence of events for the example network shown in Figure 11.4 and the locations of computers that the bridge has learned. |
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Figure 11.6 |
A bridge connecting LAN segments in two buildings. An optical fiber is used to connect the bridge to a remote LAN segment. |
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Figure 11.7 |
A bridge using a leased satellite channel to connect LAN segments at two sites. A satellite bridge can span arbitrary distance. |
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Figure 11.8 |
A bridged network that consists of eight segments connected by seven bridges. Computers can be attached to any of the segments. |
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Figure 11.9 |
An example of bridges connected in a cycle. A problem occurs if all bridges forward broadcast frames. |
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Figure 11.10 |
The concept underlying a switched LAN. Electronic circuits in the switch provide each computer with the illusion of a separate LAN segment connected to other segments by bridges. |
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Figure 13.1 |
A packet switch with two types of I/O connectors: one type is used to connect to other packet switches, and the other is used to connect to computers. |
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Figure 13.2 |
A small WAN formed by interconnecting packet switches. Connections between packet switches usually operate at a higher speed than connections to individual computers. |
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Figure 13.3 |
Example of hierarchical addresses in a WAN. Each address consists of two parts: the first part identifies a packet switch, and the second part identifies a computer connected to the switch. |
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Figure 13.4 |
(a) A network consisting of three packet switches, and (b) the next-hop forwarding information found in switch 2. Each switch has different next-hop information. |
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Figure 13.5 |
An abbreviated version of the routing table in Figure 13.4b made possible by hierarchical addressing. When forwarding to a local computer, the switch uses the second part of the address to select a specific computer. |
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Figure 13.6 |
The network from Figure 13.2 and the corresponding graph. Each node in the graph corresponds to a packet switch, and each edge between two nodes represents a connection between the corresponding packet switches. |
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Figure 14.2 |
Illustration of an ATM VC between two computers. |
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Figure 14.3 |
An illustration of three ATM switches and the forwarding table in each switch that allows a single VC to span the network. Only those table entries that correspond to the VC are shown. |
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Figure 16.8 |
A graph that represents a network of six packet switches. Such networks can experience congestion. |
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Figure 33.2 |
The interconnection of an IP telephone system with the Public Switched Telephone Network. Gateways handle both voice and signaling. |
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Animation 09_1 |
Repeaters interconnect Ethernet segments |
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Animation 09_2 |
Bridges interconnect Ethernet segments by receiving and retransmitting entire frames |
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Animation 09_3 |
Routers interconnect networks to form internets by forwarding protocol datagrams from the destination to the source |
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Photo 1_059 |
Optical fiber and connectors |
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Photo 1_060 |
Optical fiber and connectors with protective covers installed |
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Photo 2_002 |
Optical fiber patch panel |
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Photo 2_003 |
Optical fiber patch panel |
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Photo 2_004 |
Two racks of network components |
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Photo 2_007 |
Two racks of network components |
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Photo 2_009 |
Rack containing network hubs and optical fiber adapters |
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Photo 2_020 |
A serial connection switch that interconnects RS-232 serial cables, typically between terminals and serial ports on computers. |
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Photo 3_001 |
A wiring closet containing various patch panels, Ethernet switches and hubs, and ATM switches. |
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Photo 3_004 |
A closeup of two 3Com 24 port Ethernet switches, a Fore ForeRunner ASX-200 ATM switch with both twisted pair copper and fiber optic connections, and a Fore ForeRunner LE155 ATM switch with 12 twisted pair 155 megabit connections (see photo img3_001). |
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Photo 3_029 |
The front of a Proxim wireless bridge. This device bridges a wireless Proxim local area network with a standard Ethernet network. |
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Photo 3_030 |
The front of a Proxim wireless bridge. This device bridges a wireless Proxim local area network with a standard Ethernet network. |
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Photo 3_031 |
The back of a Proxim wireless bridge. On the left is an antenna. On the right is an RJ-45 Ethernet jack. To the left of that is a thin Ethernet BNC connector. |
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Photo 3_032 |
The back of a Proxim wireless bridge. On the left is an antenna. On the right is an RJ-45 Ethernet jack. To the left of that is a thin Ethernet BNC connector. |
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Photo 3_043 |
A wiring closet containing, from top to bottom, three patch panels, two Ethernet hubs, and an Ethernet switch. |
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Photo 3_044 |
A wiring closet containing, from top to bottom, three patch panels, two Ethernet hubs, and an Ethernet switch. |
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Photo 3_047 |
A wiring closet containing, from top to bottom, three patch panels, two Ethernet hubs, and an Ethernet switch. |
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Photo 3_061 |
Three 3Com Ethernet switches. |
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Photo 3_062 |
Three 3Com Ethernet switches. |
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Photo 3_067 |
A wiring closet containing various patch panels, Ethernet switches and hubs, and ATM switches. |
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Photo 3_068 |
A wiring closet containing various patch panels, Ethernet switches and hubs, and ATM switches. |
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Photo 3_069 |
A wiring closet containing various patch panels, Ethernet switches and hubs, and ATM switches. |
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Photo 3_070 |
A wiring closet containing various patch panels, Ethernet switches and hubs, and ATM switches. |
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Photo 3_071 |
A wiring closet containing various patch panels, Ethernet switches and hubs, and ATM switches. |
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Photo 3_072 |
A wiring closet containing various patch panels, Ethernet switches and hubs, and ATM switches. |
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Photo 3_073 |
A wiring closet containing various patch panels, Ethernet switches and hubs, and ATM switches. |
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Photo 3_074 |
A wiring closet. From top to bottom this closet contains three patch panels, two 3Com 24 port Ethernet switches, a Fore ForeRunner ASX-200 ATM switch with both twisted pair copper and fiber optic connections, and A Fore ForeRunner LE155 ATM switch with 12 twisted pair 155 megabit connections. |
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Photo 4_030 |
A Cisco Catalyst 3000 Ethernet switch. This switch has 16 10 megabit twisted pair Ethernet jacks along the bottom. Near the top one can also see two 100 megabit fiber optic ports covered by dust caps. |
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Photo 4_031 |
A Cisco Catalyst 3000 Ethernet switch. This switch has 16 10 megabit twisted pair Ethernet jacks along the bottom. Near the top one can also see two 100 megabit fiber optic ports covered by dust caps. |
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Photo 4_032 |
A Cisco Catalyst 3000 Ethernet switch. This switch has 16 10 megabit twisted pair Ethernet jacks along the bottom. Near the top one can also see two 100 megabit fiber optic ports covered by dust caps. |
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Photo 4_033 |
A Cisco Catalyst 3000 Ethernet switch. This switch has 16 10 megabit twisted pair Ethernet jacks along the bottom. Near the top one can also see two 100 megabit fiber optic ports covered by dust caps. |
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Photo 4_034 |
A Cisco Catalyst 5505 switch. At the top are two 100 megabit fiber optic ports with dust covers. In the slot below are two 155 megabit fiber optic ATM interfaces, also concealed by dust covers. The last occupied slot contains 24 10 megabit twisted pair Ethernet ports. The remaining two slots are empty and available for expansion. |
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Photo 4_035 |
A Cisco Catalyst 5505 switch. At the top are two 100 megabit fiber optic ports with dust covers. In the slot below are two 155 megabit fiber optic ATM interfaces, also concealed by dust covers. The last occupied slot contains 24 10 megabit twisted pair Ethernet ports. The remaining two slots are empty and available for expansion. |
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Photo 4_036 |
A Cisco Catalyst 5505 switch. At the top are two 100 megabit fiber optic ports with dust covers. In the slot below are two 155 megabit fiber optic ATM interfaces, also concealed by dust covers. The last occupied slot contains 24 10 megabit twisted pair Ethernet ports. The remaining two slots are empty and available for expansion. |
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Photo 4_037 |
A Cisco Catalyst 5505 switch. At the top are two 100 megabit fiber optic ports with dust covers. In the slot below are two 155 megabit fiber optic ATM interfaces, also concealed by dust covers. The last occupied slot contains 24 10 megabit twisted pair Ethernet ports. The remaining two slots are empty and available for expansion. |
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Photo 4_053 |
A Cisco Catalyst 5500 Ethernet Switch. The blue cables are twisted pair 10/100 megabit Ethernet. The orange lines are 10 or 100 megabit fiber optic connections. |
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Photo 4_054 |
A Cisco Catalyst 5500 Ethernet Switch. The blue cables are twisted pair 10/100 megabit Ethernet. The orange lines are 10 or 100 megabit fiber optic connections. |
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Photo 4_055 |
A Cisco Catalyst 5500 Ethernet Switch. The blue cables are twisted pair 10/100 megabit Ethernet. The orange lines are 10 or 100 megabit fiber optic connections. |
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Photo 4_056 |
A Cisco Catalyst 5500 Ethernet Switch. The blue cables are twisted pair 10/100 megabit Ethernet. The orange lines are 10 or 100 megabit fiber optic connections. |
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Photo 4_078 |
The back side of an Ethernet repeater. On the left is an RJ-45 twisted pair connector. In the middle is a thin Ethernet coaxial connector. |
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Photo 4_079 |
The back side of an Ethernet repeater. On the left is an RJ-45 twisted pair connector. In the middle is a thin Ethernet coaxial connector. |
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Photo 4_080 |
The front of an Ethernet repeater shows various status indicators. |
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Photo 6_003 |
A Cisco 2900 XL switch (2924XL-M). The switch has 24 10/100 Mbps twisted pair Ethernet ports. It also accomdates two optional modules above. This switch has an optical fiber Ethernet interface installed in the left module bay and no module on the right. |
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Photo 6_004 |
The rear of a Cisco Catalyst 8540 MSR switch. This particular switch is fully redundant with backup processor cards, network interface cards and power supplies. |
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Photo 6_005 |
The rear of a Cisco Catalyst 8540 MSR switch. This particular switch is fully redundant with backup processor cards, network interface cards and power supplies. |
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Photo 6_006 |
The front of a Cisco Catalyst 8540 switch. |
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Photo 6_007 |
The rear of a Cisco Catalyst 6500 switch. This switch includes 12 gigabit Ethernet ports as well as 48 100 Mbps fiber Ethernet ports. The smaller device on top of the switch is a gigabit Ethernet extender. The extender allows gigabit Ethernet to be run over multimode fiber optic cable for up to 2 km. The normal range for gigabit Ethernet over the same cable is about 500 ft (152 meters). |
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Photo 6_008 |
The rear of a Cisco Catalyst 6500 switch. This switch includes 12 gigabit Ethernet ports as well as 48 100 Mbps fiber Ethernet ports. The smaller device on top of the switch is a gigabit Ethernet extender. The extender allows gigabit Ethernet to be run over multimode fiber optic cable for up to 2 km. The normal range for gigabit Ethernet over the same cable is about 500 ft (152 meters). |
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Photo 6_009 |
The front of a Cisco Catalyst 6500 switch. |
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Photo 6_010 |
A Cisco Cache Engine 550 web cache (four bottom units). Each web cache contains two 9.2 GB hard disks. The four units together are intended to handle up to 45 Mbps of web traffic. A Cisco router (not shown) redirects web connections to the web caches. The router performs load balancing among the individual web caches by redirecting web traffic destined for a particular range of IP addresses to each web cache. Directly above the caches is a Cisco Catalyst 2900XL switch. On top is a 3Com 24-port, 4-segment hub. |
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Photo 6_011 |
A Cisco Cache Engine 550 web cache (four bottom units). Each web cache contains two 9.2 GB hard disks. The four units together are intended to handle up to 45 Mbps of web traffic. A Cisco router (not shown) redirects web connections to the web caches. The router performs load balancing among the individual web caches by redirecting web traffic destined for a particular range of IP addresses to each web cache. Directly above the caches is a Cisco Catalyst 2900XL switch. On top is a 3Com 24-port, 4-segment hub. |
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Photo 6_012 |
A Cisco Cache Engine 550 web cache (four bottom units). Each web cache contains two 9.2 GB hard disks. The four units together are intended to handle up to 45 Mbps of web traffic. A Cisco router (not shown) redirects web connections to the web caches. The router performs load balancing among the individual web caches by redirecting web traffic destined for a particular range of IP addresses to each web cache. Directly above the caches is a Cisco Catalyst 2900XL switch. On top is a 3Com 24-port, 4-segment hub. |
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Photo 6_013 |
A Cisco Cache Engine 550 web cache (four bottom units). Each web cache contains two 9.2 GB hard disks. The four units together are intended to handle up to 45 Mbps of web traffic. A Cisco router (not shown) redirects web connections to the web caches. The router performs load balancing among the individual web caches by redirecting web traffic destined for a particular range of IP addresses to each web cache. Directly above the caches is a Cisco Catalyst 2900XL switch. On top is a 3Com 24-port, 4-segment hub. |
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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. |
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Photo 6_020 |
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. |
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Photo 6_021 |
An ATM uplink interface board for a Cisco Catalyst 5000 switch. |
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Photo 6_022 |
An ATM uplink interface board for a Cisco Catalyst 5000 switch. |
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Photo 6_023 |
A Supervisor III board for a Cisco Catalyst 5000 switch. The Supervisor board performs high-level control and operating system tasks, not the swichting itself. |
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Photo 6_024 |
A Supervisor III board for a Cisco Catalyst 5000 switch. The Supervisor board performs high-level control and operating system tasks, not the swichting itself. |
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Photo 6_028 |
The front of the patch panel. Orange fiber optic cables attach to the fibers that come into the building and connect them to the various switches, routers and other equipment. |
