Blockchain technology allows public parties to agree on a common state without relying on a central authority. Despite it brings many innovative use cases, the technology is still in its early stage that needs improving on many aspects. One of the issues is to deliver blockchain data more efficiently. Named Data Networking (NDN), a new network paradigm, is designed to make content distribution with ease by enabling in-network caching and built-in multicasting, which blockchain technologies can take advantage. Moreover, blockchain may contribute to extending NDN application ecosystems including decentralized applications. Therefore, it is instrumental to have a working blockchain system that runs on NDN platform to supports its research and development. In this work, we design and implement an NDN-based Ethereum blockchain platform. We propose new protocols for propagating blockchain data making full use of NDN features for the delivery of transactions and blocks. Our experiments show that the distribution of blockchain data in NDN is more efficient than that of IP network. The latency of block delivery is also reduced, which in turn supports tuning blockchain parameter for better security. Our developed blockchain client is freely distributed as an open-source project. We hope that it can provide a platform to foster blockchain research on NDN in the future.

Rapid growth of Internet traffic causes a new challenge in the design of high-speed switches. One of main design issues for high-speed switches is a scalability problem. This paper proposes a scalable crossbar matrix (SCM) switch architecture, which consists of multiple crossbar switch units (XSU) with virtual output queues (VOQs) at the inputs and single-cell scheduling decomposition buffers (SDBs) at the outputs. We propose a distributed scheduling algorithm for the proposed scalable crossbar switch architecture, which consists of a credit based SLIP (C-SLIP) scheduling for crossbar switch units and backlog weighted round robin (BWRR) scheduling for switching fabric output ports. In this paper, we show that large-scale switch fabric can be built up by small-size crossbar switch units with improved delay performance and enough arbitration time margins. The simulation results show that the proposed switch architecture and distributed scheduling algorithm can provide 100% throughput under i.i.d. uniform traffic with a single iteration arbitration in a time slot.

A general expansion architecture is proposed that can be used in building large-scale switches using any type of asynchronous transfer mode (ATM) switch. The proposed universal multistage interconnection network (UniMIN) switch is composed of a buffered distribution network (DN) and a column of output switch modules (OSMs), which can be any type of ATM switch. ATM cells are routed to their destination using a two-level routing strategy. The DN provides each incoming cell with a self-routing path to the destined OSM, which is the switch module containing the destination output port. Further routing to the destined output port is performed by the destination OSM. Use of the channel grouping technique yields excellent delay/throughput performance in the DN, and the virtual FIFO concept is used for implementing the output buffers of the distribution module without internal speedup. We also propose a "fair virtual FIFO" to provide fairness between input links while preserving cell sequence. The distribution network is composed of one kind of distribution module which has the same size as the OSM, regardless of the overall switch size N. This gives good modular scalability in the UniMIN switch. Performance analysis for uniform traffic and hot-spot traffic shows that a negligible delay and cell loss ratio in the DN can be achieved with a small buffer size, and that DN yields robust performance even with hot-spot traffic. In addition, a fairness property of the proposed fair virtual FIFO is shown by a simulation study.