The overall objective of this project is to investigate and compare network architectures alternatives for cost effective, reliable, scalable and flexible IP backbones. In this project we propose to investigate key issues that will contribute to the design and assessment of integration of IP over WDM networks. IP/WDM networks will be investigated and compared with alternative backbone IP architectures according to multiple parameters (network efficiency, cost, survivability schemes, reconfigurability, QoS properties and grooming capacities). The reduction in network layers and therefore technologies in the protocol stack makes the IPover-WDM solution very attractive but challenging at the same time. Several key features that ATM and SONET/SDH offered, such as QoS, gromming capacities and survivability proprieties which need to be incorporated in the new protocol stack, will be addressed.