After quite a bit of discussion, the current plan is to do both, handle parallel searches against insitutional directories and a central deposit and let the school decide how it wants to handle its data and how it should be searched. I believe that parallel searches of multiple central deposits will prove necessary as well as a link to other communities, like the international sector and other communities of interest to higher education. Previous work developed by Roland Hedberg and should seek his expertise and understand the applicability. Include the European community in our efforts Architecturally speaking, the central deposit should be directory independent. The following text is email from Roland Hedberg giving his thoughts on this project.
Lets start with some math.
Further assume that these persons will use the directory for white pages lookups twice a week. Surely there will be peaks that are a lot bigger. Now in your testbed it took 30 seconds to get back the answers for some query. 30.000 simultaneous open outgoing connections from one machine unless you do something very sofisticated like keeping a couple of connections open all the time to all the LDAP servers and just distribute the queries over the pipes. Still I think you would have to find a decent machine to be able to cope with that.