This example demonstrates how to display active network layer routes in a
network. An active route is created when a packet gets delivered by the network
from one node to another. Active routes become inactive over time unless they
are reinforced by new packets.

There are two networks in this example, a static wired network, and a dynamic
wireless mobile network. The networks contain a source node, a destination node,
and a number of intermediate nodes. In both of them the source node continuously
pings the destination node. In the wired network, nodes are stationary and links
don't break, so the established route is static. In the wireless network, all
nodes move around randomly, so links might break, and thus every now and then a
new route has to be found.

When you run the example, the route visualizer eventually displays the discovered
route as a polyline along the nodes. In the wireless example, every now and then
the current route disappears, but a new route appears again once it is found.
