Search

IoT remote control is faced with scalability, secure communication and privacy preservation issues and conventional solutions (HTTPS) have disclosed poor scaling problem and privacy concerns. In this paper, we propose a novel lightweight and secure IoT remote monitoring mechanism using DNS with privacy preservation. Basically, the communication between IoT devices and gateways uses the conventional protocols as usual such as CoAP and MQTT while only the remote monitoring uses DNS protocol. That is, encrypted IoT data, after being encoded with base64, is stored as a DNS TXT record of the domain name of the IoT device and only the designated users are allowed to query and decrypt the data based on TSIG authentication of DNS protocol and asymmetric cryptography. We implemented a prototype system over name-bound virtual networks (NBVNs) in which all virtual nodes are registered in DNS automatically and the network traffic is restricted within each NBVN. Through the preliminary evaluations we confirmed the effectiveness of secure communication and privacy preservation in IoT remote monitoring in the proposed mechanism.

Hierarchically structured addresses have been proposed to improve the scalability of the Internet. However, the crucial component and primary challenge of hierarchical addressing is the locator selection because the number of locators could be unmanageably large. In this paper, we propose two methods to select and allocate locators. The first method can reduce the number of locators and Forwarding Information Base (FIB) entries, but it fails to address the path stretch problem. In the second approach, we leverage hierarchical address allocation and flat identifiers to efficiently represent locators. Provider-based locators can be aggregated to reduce the number of FIB entries, while provider-independent locators can help to reduce path stretch. We investigate the performance and efficiency of the two approaches by performing a large-scale measurement based on today's Internet topology. Our evaluation shows that the second approach could reduce the number of locators with small path stretch.

To enable billions of devices to communicate with each other simultaneously, small end-to-end latency and high scalability and reliability are the essential characteristics for the Internet of Things (IoT). The transition from today's Internet to IoT has demanded a new information and communications infrastructure. In this paper we implement and deploy a scalable and reliable inter-domain infrastructure, LORIF proposed in our previous work, to meet the requirements of IoT. Based on two local network testbeds and an intercontinental network testbed, we evaluate the scalability, resilience, and mobility of LORIF. The results demonstrate that LORIF can provide low end-to-end latency and high scalability and reliability.

In this paper, we propose a mechanism for autoconfiguration of name-bound virtual networks (NBVNs) for Internet of Things (IoT). Some IoT standardization groups have defined APIs for IoT device communications, in which they indicate the correspondent nodes and resources by names. However, current technologies for the construction of Virtual Networks (VNs) rely on VLANs, IP routing, and OpenFlow control, thus they do not provide a name-based solution. Our proposal fills this gap. We first define business players that construct and use the NBVNs. They are Application Service Provider (ASP), Virtual Network Operator (VNO), and Infrastructure Provider (InP). We then specify the roles of ASP/VNO/InP, including the tasks that must be performed by their managers, and the required interactions for the purpose of autoconfiguration. Subsequently, we describe the system we developed to implement the operations of ASP/VNO/InP and thus construct NBVNs automatically. For each NBVN, the required IPv6 addresses are automatically allocated and assigned to the network nodes, including the IoT devices. Moreover, data forwarding and name resolution mechanisms are also configured automatically. Thus, the proposed system constructs area-and/or time-bound VNs for offering network services to event-centric IoT applications, such as outdoor concerts and sporting events. Finally, we demonstrate that the constructed NBVNs are capable to configure thousands of addresses and name entries within a minute, thus IoT devices can communicate among them by using their correspondent node names instead of their addresses. Moreover, both ASP and VNO can operate the servers, switches, and routers pertaining to the NBVNs by also using their names.

A low-latency and reliable message switching network is critical for constructing high-speed datacenter networks. In this paper, we present the design, implementation, and evaluation of a novel Location basEd Source Switching (LESS) for datacenter networks. LESS enables lightweight source switching through a location-based addressing scheme. Each switch and host can independently derive a source route to reach a destination without requiring the full knowledge of the network topology. We demonstrate that using location-based source routes as forwarding labels allows LESS to eliminate the need for routing tables and integrate with minimum required functionality for packet forwarding. Moreover, we propose a fast rerouting solution to address the issue of fault tolerance in source routing. Each switch can locally derive an alternative source route during a failure. The paper evaluates the performance of LESS. Our evaluation results suggest that LESS improves the performance of datacenter networks in terms of latency, throughput, and reliability.

An optical packet and circuit integrated network (OPCInet) provides both high-speed, inexpensive services and deterministic-delay, low-data-loss services according to the users’ usage scenarios, from the viewpoint of end users. From the viewpoint of network service providers, this network provides large switching capacity with low energy consumption, high flexibility, and efficient resource utilization with a simple control mechanism. This paper presents the recent progress made in the development of OPCInet and its extension to software-defined networking (SDN). We have developed OPCI nodes, which are capable of layer 3 switching from/to an Ethernet frame to/from an optical packet in the optical packet edge part and a burst-tolerant optical amplifier and an optical buffer with optical fiber delays in 100 Gbps optical packet switching part. The OPCI node achieves a packet error rate less than $10^{-4}$ and is used as a node in a lab-network that has access to the Internet. A distributed automatic control works in a control plane for the circuit switching part and in a moving boundary control between optical packet resources and circuit resources. Our optical system for packet and circuit switching works with a centralized control mechanism as well as a distributed control mechanism. We have shown a packet-based SDN system that configures mapping between IP addresses and OPCI node identifiers and switching tables according to the requests from multiple service providers via a web interface.

Hierarchical addressing and locator/ID separation solutions have been proposed to address the scalability issue of the Internet. However, how to combine the two addressing schemes has not been received much attention. In this paper, we present an address encoding method to integrate hierarchical addressing and locator/ID separation. Our analysis and evaluation results show that the proposed encoding method could guarantee the scalability property, and alleviate the inefficiency of address space.

The Internet is facing the accelerating growth of routing table size. Backbone routers' routing table has already reached 512k entries, which has a negative effect on the scalability of the Internet. Hierarchical addressing and locator/ID separation solutions have been proposed to address the scalability issue. However, there has been little focus on how to efficiently represent hierarchical location addresses for a large scale distributed network, such as today's Internet. In this paper, we present a variable-length address encoding method to represent hierarchical location addresses. Our analysis and evaluation results show that 1) it is difficult to use fixed-length encoding to represent hierarchical location addresses for a large scale network; and 2) the proposed variable-length addresses could guarantee the scalability property of hierarchical addressing, and alleviate the inefficiency of address space due to fixed-length addresses.

According to the Domain Name Industry Brief 2015 by VeriSign, the amount of domain names has reached to 296 million across all top-level domains (TLDs) with increase of 5.9 percent year over year. Considering each domain name may have at least one resource record requiring multi-step name resolution such as MX (Mail eXchange), CNAME (Canonical Name) and SRV (Service), etc. the DNS traffic and name resolution delay is in increase trend. In this paper, we propose a secure prefetch mechanism for multi-step name resolution in DNS to speedup the Internet services that use those records and reduce DNS traffic. We implemented a prototype system by customizing conventional BIND (Berkeley Internet Name Domain) on Linux system and evaluated the proposed mechanism using domain name measurement tool. The results confirmed that the prototype system worked properly as we designed. Moreover, we compared the latency of multi-step name resolution in the prototype system with that in the conventional BIND and confirmed that not only the number of query times but also approximately 30% of latency can be reduced in our proposed mechanism.

Previous studies showed that water-free, premixed calcium phosphate cements (Pre-CPCs) exhibited longer hardening times and lower strengths than conventional CPCs, but were stable in the package. The materials hardened only after being delivered to a wet environment and formed hydroxyapatite as the only product. Pre-CPCs also demonstrated good washout resistance and excellent biocompatibility when implanted in subcutaneous tissues in rats. The present study evaluated characteristics of Pre-CPCs when implanted in subcutaneous tissues (Study I) and used for repairing surgically created two-wall periodontal defects (Study II). Pre-CPC pastes were prepared by combining CPC powders that consisted of CPC-1: Ca(4)(PO(4))(2)O and CaHPO(4), CPC-2: α-Ca(3)(PO(4))(2) and CaCO(3) or CPC-3: DCPA and Ca(OH)(2) with a glycerol at powder-to-liquid mass ratios of 3.5, 2.5, and 2.5, respectively. In each cement mixture, the Ca to P molar ratio was 1.67. The glycerol contained Na(2)HPO(4) (30 mass %) and hydroxypropyl methylcellulose (0.55 %) to accelerate cement hardening and improve washout resistance, respectively. In Study I, the test materials were implanted subcutaneously in rats. Four weeks after the operation, the animals were sacrificed and histopathological observations were performed. The results showed that all of the implanted materials exhibited very slight or negligible inflammatory reactions in tissues contacted with the implants. In Study II, the mandibular premolar teeth of mature beagle dogs were extracted. One month later, two-wall periodontal bone defects were surgically created adjacent to the teeth of the mandibular bone. The defects were filled with the Pre-CPC pastes and the flaps replaced in the preoperative position. The dogs were sacrificed at 1, 3 and 6 months after surgery and sections of filled defects resected. Results showed that one month after surgery, the implanted Pre-CPC-1 paste was partially replaced by bone and was converted to bone at 6 months. The pockets filled with Pre-CPC-2 were completely covered by newly formed bone in 1 month. The Pre-CPC-2 was partially replaced by trabecular bone in 1 month and was completely replaced by bone in 6 months. Examination of 1 month and 3 month samples indicated that Pre-CPC-2 resorbed and was replaced by bone more rapidly than Pre-CPC 1. Both Pre-CPC pastes were highly osteoconductive. When implanted in periodontal defects, Pre-CPC-2 was replaced by bone more rapidly than Pre-CPC-1.

A calcium phosphate cement (CPC-1), prepared by mixing an equimolar mixture of tetracalcium phosphate and dicalcium phosphate anhydrous with water, has been shown to be highly biocompatible and osteoconductive. A new type of calcium phosphate cement (CPC-2), prepared by mixing a mixture of alpha-tricalcium phosphate and calcium carbonate with pH 7.4 sodium phosphate solution, was also reported to be highly biocompatible. The objective of the present study was to compare the osteoconductivities of CPC-1 and CPC-2 when implanted in surgically created defects in the jaw bones of dogs. At 1 month after surgery, implanted CPC-1 was partially replaced by new bone and converted to bone within 6 months. In comparison, at 1 month after surgery, the defect filled with CPC-2 was mostly replaced by new bone. Therefore, bone formation in CPC-2-filled pocket was more rapid than in CPC-1-filled pocket. These findings supported the hypothesis that CPC-2 converted to bone more rapidly than CPC-1.

Hierarchical address allocation and hierarchical routing design has long been suggested to reduce the forwarding information base (FIB) size in the Internet core. However, the hierarchical design is not put into practice. We implemented the hierarchical and automatic number allocation (HANA) protocol for allocation of IPv4 and IPv6 address spaces to autonomous systems (ASes) and the FIB size reduction. The HANA protocol allocates multiple address spaces to an AS from the upper ASes. Multihoming using multiple addresses provides an AS with multiple paths. That is, detour paths are inevitably prepared in advance, even when a network failure does not occur. In this paper, we provide the highest flexibility to HANA-based networking, namely, supporting variable-length addressing scheme. The variable-length addressing schemes suppress renumbering caused by the address space extension that occurs in the fixed-bit-length addressing schemes. In addition, we propose a new function of exchanging allocated numbers, and implement it in the current HANA system. The flexible HANA system provides locator allocation with low renumbering costs and realizes scalable addressing in future internetworking.