0626397, 0626738, and 0627161 Walrand et. al<br/><br/><br/><br/>This proposal studies how the network architecture can enable markets for network services and for security improvements of the network. The premise of the research is that economic incentives drive the development and deployment of technology. Such incentives exist if there is a market where suppliers and buyers can meet. In today's Internet, such a market is missing. For instance, users cannot choose different types of communication services. Also, incentives are missing for improved security measures. The research explores the potential benefits of improved user choice and of incentives for security. Such benefits depend on the network architecture, including differentiated forwarding of packets of various types and pricing stamps on packets. The study combines models of user utilities and network performance to compare the benefits of different architectures. <br/><br/>The potential broader impact of this research is a set of architectural choices that would enable the free market to drive substantial improvement of the network services and security.