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overlay network. |
overlay network. |
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In the end, however, we observe that there are only two approaches in which all modern Peer-to-Peer |
In the end, however, we observe that there are only two approaches in which all modern Peer-to-Peer |
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systems fall: the loosely structured approach and the tightly structured approach. In the loosely |
systems fall: the loosely structured approach and the tightly structured approach. By structure, we refer to |
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structured approach the construction and the maintenance of the overlay is controlled |
the topology of the overlay network, i.e., how the connections between participating peers are created |
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loosely. This approach gives freedom for participating peers |
and maintained. In the loosely structured approach the construction and the maintenance of the overlay is controlled |
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to perform certain tasks in a Peer-to-Peer network. On the other hand in the tightly structured |
loosely. The placement of services and topology of the overlay is random. Data lookups in loosely structured systems are |
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approach, the overlay is constructed determistically, which all participating peers have to follow. |
not very efficient, because of unstructured properties of the overlay. On the other hand, in the tightly structured |
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approach the overlay is constructed determistically, which all participating peers have to follow. The topology of the |
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overlay and the placement of services is controlled tightly therefore enabling more scalable and efficient data lookups. |
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In the following sections, we will discuss in more detail the properties of these approaches. |
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\section{Centralized} |
\section{Centralized} |