old bearshare forcing connection as ultrapeer?

Do you remember the very old bearshare version which was able to connect to
the network always as an ultrapeer (that was an option in the configuration
menu)? My question is: I've read the Gnutella documentation several times. I
don't recall reading there anything related to forcing ultrapeer mode in the
protocol messaging itself. Does anybody knows how that bearshare version
works? I have it, for research purposes, and it still loads and connects as
an ultrapeer (I can have leafs connected in a couple of minutes). So,
somehow, other peers understand my PC is already an ultrapeer. I understand
there are some rules a peer needs to comply in order to become an ultrapeer.
But, how exactly? is that coded in each gnutella client? or is it part of
the protocol?
thanks,
Miguel


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