Recent research publications have noted the possibility that plain-old IGP metric manipulations may be as effective as the overlay-style traffic engineering made possible by ATM or MPLS. Adherents of either approach have pointed to specific topologies for which metric manipulation does extremely well or extremely poorly. Here, we present the results of a study comparing metric-based shortest-path routing with the theoretically optimal routing.
We looked at six real networks under normal and single-circuit
failures and found that, despite its limitations, metric-based
routing was able to minimize maximum link utilizations about as well
as the theoretical maximum. We present cases that illustrate the
limitations of metric-based routing and speculate that these cases do
not affect performance on existing networks because operators design
networks with shortest-path routing limitations in mind.
About the Presenter
Arman Maghbouleh's research interests are in reformulation of
difficult combinatorial optimization problems into simple-to-solve
approximations. At Cariden, he works with network operators to
develop routing and traffic management solutions. Arman holds
post-graduate degrees in Computer Science, Statistics, and
Linguistics from Yale and Stanford Universities.