A network topology based on Nano Data Centers (NDC) for an interactive collaborative system is discussed in this paper. The system operates over several nodes that differ in endpoint security and network access. Some nodes are prevented from initiating connections directly and require intermediate nodes to accept requests from third parties. The nodes also constitute a supporting content distribution network. In an interactive system, latency is an important factor in overall system performance. In the context of this paper, users are scattered over a large geographic area and connect to the system at their own convenience. Thus it is necessary to find optimal positions for NDC nodes such that relaying leads to minimal increases in response time for all users. In this paper, an extended hierarchical clustering algorithm is used to create a set of NDC locations across a geographic region. It generates a set of relay locations that can be used in P2P communication.