Overview
Internet Routing: An Overview
We have seen that telephone networks are notable for the
predictability of their traffic flows and their relatively small
cores.
The environment of the Internet is very different:
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Links and routers are unreliable.
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Alternative paths are scarce
-
Traffic patterns change unpredictably within minutes.
Routing strategies in such an environment therefore have to be much
more tolerant of changes in the network than are the strategies for
telephone networks. The two fundamental routing algorithms in
packet-switched networks (the Internet and ATM networks) are:
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Distance-Vector (based on the Bellman-Ford
Algorithm).
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Link-State (based on Dijkstra's
Algorithm).
We will examine each of these routing strategies in turn.
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