Evaluation of a Multiobjective Alternative Routing Method in Carrier IP/MPLS Networks

We present a first simplified version of the MultiObjective Dynamic Routing (MODR) method, more suitable for a realistic network environment as the computational effort is very much reduced while good results can still be reached. The simplified version presented herein is based on the results obtained from a discrete event simulation study which shows that, in case of overload, more important than the alternative routing algorithm itself is to control the excess of alternative routing traffic. Moreover, in a multiservice network in the case of lightly loaded traffic conditions, when alternative routing starts to be effective, network performance can still be improved if we can avoid alternative routing for specific traffic flows. Classical dynamic alternative routing methods for traditional ISDN networks have a trunk reservation mechanism with a similar purpose but apparently without the same performance. Our method applies to MPLS strongly meshed networks which are typical of core networks.