Ambient Networks have been getting attention in the last years, mainly due to the concept of network composition, aimed at providing dynamic and instant service and resource access to users. Now, the main challenge is to build a bridge between theory and practice. This paper presents a prototype implementation of a Policy-based Management (PBM) approach for network composition that uses a tree-based data model mapped on a peer-to-peer storage mechanism. The main goal is to discuss the key design decisions and the experience with the implementation and deployment of the prototype. Also, we conducted a measurement-based performance analysis and present the results and a discussion of the strategies chosen as well as its benefits and pitfalls.