CONCLUSION
Congestion aware routing has been investigated in
nonlinear elastic optical networks and shown to be effective
for the reference NSFNET topology. We observe that the
network blocking probability (NBP) follows a generalized
extreme value distribution, allowing robust estimates of the
load for a given NBP to be obtained. When NSFNET is
sequentially loaded with 100 GbE demands the proposed
algorithm with a 6.25 GHz flexgrid, allows the network to
support 1744 demands compared to 328 demands using a fixed
50 GHz grid with shortest path routing for NBP = 1%. The
congestion aware routing algorithms investigated resulted in
longer average paths, with 5% of all routes exceeding the
maximum shortest path in order to increase the overall network
capacity.