Previous studies of search in channel graphs has assumed that the search is
global; that is, that the status of any link can be probed by the search
algorithm at any time. We consider for the first time local search, for which
only links to which an idle path from the source has already been established
may be probed. We show that some well known channel graphs may require
exponentially more probes, on the average, when search must be local than when
it may be global.Comment: i+13 pages, 2 figure
