[tor-dev] How does a hidden service select introduction points

Hi guys,

i have been doing a bit of reading recently about hidden services, and i am just wondering how exactly a hidden service selects its introduction points, i understand there are two methods, one where the H.S picks its own set of I.P's and one where this is done for the H.S., is this correct?

If so is there an algorithm for automatically selecting introduction points for a hidden service and is one method recommended over another, if so why?

Finally how many introduction points does a H.S. usually have, can a larger H.S. have more I.P's to deal with the traffic or is this not advised ?

Thanks for the help

Rich