The growth of commercial activities across networks has led to the network itself becoming a competitive marketplace with a multitude of vendors, operators and customers. In such an environment, users will `shop around' for the best deals in terms of network financial costs and services. Intelligent, autonomous and mobile software agents introduce an alternative approach that facilitates expertise-brokering activities on behalf of the users. In this paper we present such an agent supported brokering scenario. The scenario involves interactions between Java-based mobile agents and an interactive model of the network. The paper describes how this prototyping environment can be used to examine the impact of mobile agents for brokering network resources in the future open network marketplace.