  We compare the long-term, steady-state performance of a variant of the
standard Dynamic Alternative Routing (DAR) technique commonly used in telephone
and ATM networks, to the performance of a path-selection algorithm based on the
"balanced-allocation" principle; we refer to this new algorithm as the Balanced
Dynamic Alternative Routing (BDAR) algorithm. While DAR checks alternative
routes sequentially until available bandwidth is found, the BDAR algorithm
compares and chooses the best among a small number of alternatives.
  We show that, at the expense of a minor increase in routing overhead, the
BDAR algorithm gives a substantial improvement in network performance, in terms
both of network congestion and of bandwidth requirement.
