We describe the architecture of a network, in which the traffic ow is controlled by a market. The network access is controlled by a trusted access node, that separates traffic into best effort and first class traffic, adds a source route header, and shapes the traffic. The network core consists of rapid forwarding devices, such as label switches, and source routing gateways. Network services, including dynamic routing, load balancing, and fault tolerance, are built by bundling the transmission capacity in several independent network domains into a service, a bundle of resources with the right properties. The service is priced as financial derivative contract, and traded on a market, independent of the network access control. Besides describing the network model, we show how to implement parts of the network access node functionality on a standard Linux machine. The implementation has been tested on a system of virtual Linux machines.