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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 13.7 |
The routing table for each node in the graph of Figure 13.6. The
next-hop field in an entry contains a pair (u,v) to denote the edge
in the graph from node u to node v.
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Figure 13.8 |
Revised version of the routing tables in Figure 13.7. An asterisk in
the column labeled destination denotes a default route.
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Figure 13.9 |
A graph with weights assigned to edges. The shortest path between
nodes 4 and 5 is shown darkened. The distance along the path
is 19, the sum of the weights on the edges.
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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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