Abstract: Peer-to-Peer systems have proven to be an effective way of sharing
data. The focus of this paper is on distributed search based on Peer-to-Peer
technology. In this paper we present the pRoute system where peers advertise a
short description of the content that they share, namely a set of terms. Peers
remember the advertisements of related peers and thereby form a semantic
overlay by which we mean that peers with similar content are grouped together.
Peers calculate the similarity between their content descriptions by a term
similarity function which, in the ideal case, is identical for all peers. In
simulation experiments we compare the performance of different advertisement-
and forwarding policies with respect to precision, recall and the number of
messages. The results indicate precision and recall increase when the policies
take semantics into account, without an increase of the number of
advertisement- and query messages.