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Photonic Systems Brown Bag Seminar Series
Thursday, November 3, 2005, at 12
noon
RLE Haus Conf.
room 36-428
Dynamic
Reconfiguration and Routing Algorithms for
IP-over-WDM
Networks with Stochastic Traffic
Andrew
Brzezinski
We
develop algorithms for joint IP layer routing and WDM logical
topology
reconfiguration in IP-over-WDM networks experiencing stochastic
traffic.
At the WDM layer, we associate a non-negligible overhead with
WDM
reconfiguration, during which time tuned transceivers cannot
service
backlogged data. The IP layer is modeled as a queueing
system. We
demonstrate that our algorithms achieve asymptotic throughput
optimality
by using frame-based maximum weight scheduling decisions.
We study both fixed and variable frame durations. In addition
to dynamically triggering WDM reconfiguration, our algorithms
specify precisely how to route packets over the IP layer during
the phases in which the WDM layer remains fixed. We demonstrate
that optical layer constraints do not affect our results, and
provide an analysis of the specific case of WDM networks with
multiple ports per node.
In order to gauge the delay properties of our algorithms, we
conduct a
simulation study and demonstrate an important trade-off between
WDM
reconfiguration and IP layer routing. We find that multi-hop
routing is
extremely beneficial at low throughput levels, while single-hop
routing
achieves improved delay at high throughput levels. For
a simple access
network, we demonstrate through simulation the benefit of employing
multi-hop IP layer routes.
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