A number of distributed hash table (DHT)-based protocols have been proposed to address the issue of scalability in peer-to-peer networks. In this paper, we present Ulysses, a peer-to-peer network based on the butterfly topology that achieves the theoretical lower bound of (log n)/(log log n)on network diameter when the average routing table size at nodes is no more than log n. Compared to existing DHT-based schemes with similar routing table size, Ulysses reduces the network diameter by a factor of log log n. which is 2-4 for typical configurations. This translates into the same amount of reduction on query latency and average traffic per link/node. In addition, Ulysses maintains the same level of robustness in terms of routing in the face of faults and recovering from graceful/ungraceful joins and departures, as provided by existing DHT-based schemes. The performance of the protocol has been evaluated using both analysis and simulation.

Bowman is an extensible platform for active networking: it layers active networking functionality in user space software over variants of the System V UNIX operating system. The packet processing path implemented in Bowman incorporates an efficient and flexible packet classification algorithm, supports multi-threaded per-flow processing, and utilizes real time processor scheduling to achieve deterministic performance in the user-space. In this paper we describe the design and implementation of Bowman; discuss the support that Bowman provides for implementing execution environments for active networking; discuss the network-level architecture of Bowman that can be used to implement virtual networks; and present performance data showing that Bowman is able to sustain 100 Mbps throughput while forwarding IP packets over fast Ethernets.