Distributed Hash Queues: Architecture and Design

We introduce a new distributed data structure, the Distributed-Hash Queue, which enables communication between Network-Address Translated (NATed) peers in a P2P network. DHQs are an extension of distributed hash tables (DHTs) which allow for push and pop operators vs. the traditional DHT put and get operators. We describe the architecture in detail and show how it can be used to build a delay-tolerant network for use in P2P applications such as delayed-messaging. We have developed an initial prototype implementation of the DHQ which runs on PlanetLab using the Pastry key-based routing protocol.