Victor Cionca

LSCHC: Layered Static Context Header Compression for LPWANs

Supporting IPv6/UDP/CoAP protocols over Low Power Wide Area Networks (LPWANs) can bring open networking, interconnection, and cooperation to this new type of Internet of Things networks. However, accommodating these protocols over these very low bandwidth networks requires efficient header compression schemes to meet the limited frame size of these networks, where only one or two octets are available to transmit all headers. Recently, the Internet Engineering Task Force (IETF) LPWAN working group drafted the Static Context Header Compression (SCHC), a new header compression scheme for LPWANs, which can provide a good compression factor without complex synchronization. In this paper, we present an implementation and evaluation of SCHC. We compare SCHC with IPHC, which also targets constrained networks. Additionally, we propose an enhancement of SCHC, Layered SCHC (LSCHC). LSCHC is a layered context that reduces memory consumption and processing complexity, and adds flexibility when compressing packets. Finally, we perform calculations to show the impact of SCHC/LSCHC on an example LPWAN technology, e.g. LoRaWAN, from the point of view of transmission time and reliability.

Exploiting pitfalls in software-defined networking implementation

The centralised control provided by Software- Defined Networking allows an increase in network security as all traffic can be vetted before leaving the attachment switch. Nevertheless, as in any complex system, there are implementation and policy compromises which lead to security vulnerabilities. This paper exploits such vulnerabilities to implement a suite of attacks, consisting of Address Resolution Protocol (ARP) cache poisoning, Man in the Middle, a firewall and access control bypassing port scan called a Phantom Host Scan, and a Distributed Denial of Service attack called a Phantom Storm which induces the participation of legitimate hosts. These attacks were successfully implemented in a Floodlight controlled network.

The Presidium of Wireless Sensor Networks - A Software Defined Wireless Sensor Network Architecture

Software Defined Networking (SDN) is emerging as a key technology to deal with the ever increasing network management burden created by our increasingly interconnected world. Wireless sensor network (WSN) are part of this interconnection, enabling to connect the physical world to the cyber world of the Internet and its networks. This connection of physical items, “Things”, to the Internet in the form of an Internet of Things is creating many new challenges for the management of the Internet networks. SDN moves away from a distributed management approach that has been at the core of wireless sensor networks since their inception and introduces a centralised view and control of a network. We believe that the SDN concept as well as the general compute virtualisation enabled through infrastructure as a service can offer the required flexible management and control of the network of Things. While the application of SDN to WSN has already been proposed, a comprehensive architecture for Software Defined Wireless Sensor Networks (SD-WSN) is currently missing. This paper provides a survey of related work considering both SDN and centralised non-SDN approaches to network management and control, examines the challenges and opportunities for SD-WSNs, and provides an architectural proposal for SD-WSN.

Detecting Link Fabrication Attacks in Software-Defined Networks

The Link Fabrication Attack (LFA) in Software-Defined Networking (SDN) involves an attacker forging a new link in the network, providing them with control over traffic which traverses the new malicious link. One method to perform this attack is through the relaying of topology discovery traffic, for which no comprehensive defense exists. This paper proposes to detect this attack using statistical analysis of link latencies. A novel solution has been designed requiring a new link to undergo a vetting period during which its latency is evaluated. This is subsequently compared against a baseline model for benign links. This solution is assessed against several implementations of the relay-type LFA. The trade-off between the length of the vetting period and the accuracy of the attack detection is analyzed. The results show how user-space relaying causes a sizable increase in latency which can be detected with a low number of samples, while relaying using kernel-space forwarding requires larger samples sets in order to be discovered.

Into the SMOG: The Stepping Stone to Centralized WSN Control

Previous research has shown that centralized network control in Wireless Sensor Networks (WSNs) can lead to improved network lifetime, benefit reliability, help to diagnose and localize network failures, assist network recovery, and lead to optimal routing and transmission scheduling. A stepping stone to centralized network control is to build and maintain a complete network topology model that scales and reacts to the network dynamics that occur in low-power wireless networks. We propose SMOG as a mechanism to build and maintain a centralized full network topology model using probabilistic data structures. Extensive analysis of the proposed approach in both simulation and two testbeds shows that SMOG can build a complete model of a WSN of over 100 nodes with 98% accuracy in less than four minutes. Our approach also offers fast recovery from heavy network interference, recovering model accuracy to 98% in less than two and a half minutes.

Challenges in supporting diverse applications in a shared WSN: The Motley middleware

Accommodating multiple different applications on a single sensor node or within the same wireless sensor network (WSN) offers numerous benefits including reduced deployment cost and improved utilization of the physical substrate. This paper presents a new middleware for WSNs, called Motley. Motley, enables a shared infrastructure and multi-application support for WSNs by providing services for the dissemination, installation and scheduling of applications with diverse QoS requirements. Implementation challenges and the measures employed in Motley to overcome these as part of a shared WSN substrate are discussed. Some initial findings on the cost in terms of code loading time to support multiple applications are presented as part of this paper.