Dynamic grooming in IP over WDM networks: A study with realistic traffic based on GANCLES simulation package

Dynamic grooming capabilities lies at the hearth of many envisaged scenarios for IP over Optical networks, but studies on its performance are still in their infancy. This work addresses two fundamental aspects of the problem. First of all it presents a novel tool for the study of IP over Optical networks. The tool, freely available on-line, is a network level simulator named GANCLES that includes several innovative features allowing the study of realistic scenarios in IP over Optical networking, making it an ideal tool for Traffic Engineering purposes. GANCLES architecture enables the simulation of dynamic traffic grooming on top of a realistic network model that correctly describes the logical interaction between the optical and the IP layer, i.e., the mutual relationship between routing algorithms and lightpath assignment procedures at the optical layer and routing at the IP layer. Adding or removing lightpaths changes the logical IP topology, which affects IP routing and traffic patterns. The simulator allows for the description of Overlay, Augmented or Peer IP over Optical architectures, depending on the amount of information shared between the IP and optical domain. Second it analyzes and discusses several performance indices and aspects of different grooming policies in the IPO Overlay model, using different traffic models, some of them including elasticity of best effort traffic. Both regular and mesh topologies are analyzed, and results clearly show that the correct evaluation of dynamic grooming policies in IPO networks requires a sophisticated level of modeling, since simplistic assumptions like Poisson traffic, or the incorrect representation of the interaction of IP and Optical control planes, may induce misleading results.