This paper describes the architecture of the KD-RTI developed by us. It concentrates on the design decisions that were made that affected the ability of the RTI to improve the performance of federated simulations. The KD-RTI provides a fully distributed infrastructure. The majority of the operations are performed in a peer to peer manner rather than through accessing a central RTI server. This provides considerable runtime benefits through the use of local calls for data transportation and lookup functions. The development of KD-RTI has highlighted key issues should be addressed in most distributed systems.