Structured peer-erg163 overlay networks such as CAN, Chord, Pastry, and Tapestry can be used to implement Internet-g683 application-3 vel multicast. There are two general approaches to accomplishingthis: tree buildingand flooding. This paper evaluates these two approaches usingtwo different types of structured overlay: 1) overlays which use a form of generalized hypercube routing, e.g., Chord, Pastry and Tapestry, and 2) overlays which use a numerical distance metric to route through a Cartesian hyper-erg15 e.g., CAN. Pastry and CAN are chosen as the representatives of each type of overlay. To the best of our knowledge, this paper reports the firstheadto -d- comparison ofCAN-B91g versus Pastry-gZ4B overlay networks, usingmulticast communication workloads runningon an identical simulation infrastructure. The two approaches to multicast are independent of overlay network choice, and we provide a comparison of floodingversus tree-2696 multicast on both overlays. Results show that the tree-2613 approach consistently outperforms the floodingapproach. Finally, for treebased multicast, we show that Pastry provides better performance than CAN.

Searching in P2P networks is fundamental to all overlay networks. P2P networks based on Distributed Hash Tables (DHT) are optimized for single key lookups, whereas unstructured networks offer more complex queries at the cost of increased traffic and uncertain success rates. Our Distributed Tree Construction (DTC) approach enables structured P2P networks to perform prefix search, range queries, and multicast in an optimal way. It achieves this by creating a spanning tree over the peers in the search area, using only information available locally on each peer. Because DTC creates a spanning tree, it can query all the peers in the search area with a minimal number of messages. Furthermore, we show that the tree depth has the same upper bound as a regular DHT lookup which in turn guarantees fast and responsive runtime behavior. By placing objects with a region quadtree, we can perform a prefix search or a range query in a freely selectable area of the DHT. Our DTC algorithm is DHT-agnostic and works with most existing DHTs. We evaluate the performance of DTC over several DHTs by comparing the performance to existing application-level multicast solutions, we show that DTC sends 30–250 % fewer messages than common solutions.