  Burst contention is a well-known challenging problem in Optical Burst
Switching (OBS) networks. Contention resolution approaches are always reactive
and attempt to minimize the BLR based on local information available at the
core node. On the other hand, a proactive approach that avoids burst losses
before they occur is desirable. To reduce the probability of burst contention,
a more robust routing algorithm than the shortest path is needed. This paper
proposes a new routing mechanism for JET-based OBS networks, called Graphical
Probabilistic Routing Model (GPRM) that selects less utilized links, on a
hop-by-hop basis by using a bayesian network. We assume no wavelength
conversion and no buffering to be available at the core nodes of the OBS
network. We simulate the proposed approach under dynamic load to demonstrate
that it reduces the Burst Loss Ratio (BLR) compared to static approaches by
using Network Simulator 2 (ns-2) on NSFnet network topology and with realistic
traffic matrix. Simulation results clearly show that the proposed approach
outperforms static approaches in terms of BLR.
