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Assumes
the Internet is an arbitrarily interconnected
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set
of AS's. Define local traffic as traffic that
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originates
at or terminates on nodes within an AS,
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and transit
traffic as traffic that passes through
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an
AS, we can classify AS's into three types:
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| n |
Stub
AS: an AS that has only a single connection to one
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other
AS; such an AS will only carry local traffic.
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| n |
Multihomed
AS: an AS that has connections to more than
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one
other AS, but refuses to carry transit traffic.
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| n |
Transit
AS: an AS that has connections to more than one
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other
AS, and is designed to carry both transit and local
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traffic.
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