Implementation and evaluation of open source unified communications for SMBs

Unified Communication (UC) is the integration of two or more real time communication systems into one platform. Integrating core communication systems into one overall enterprise level system delivers more than just cost saving. These real-time interactive communication services and applications over Internet Protocol (IP) have become critical in boosting employee accessibility and efficiency, improving customer support and fostering business agility. However, some small and medium-sized businesses (SMBs) are far from implementing this solution due to the high cost of initial deployment and ongoing support. In this paper, we will discuss and demonstrate an open source UC solution, viz. “Asterisk” for use by SMBs, and report on some performance tests using SIPp. The contribution from this research is the provision of technical advice to SMBs in deploying UC, which is manageable in terms of cost, ease of deployment and support.

Robust Controller Design of Networked Control Systems with Nonlinear Uncertainties

We address robust stabilization problem for networked control systems with nonlinear uncertainties and packet losses by modelling such systems as a class of uncertain switched systems. Based on theories on switched Lyapunov functions, we derive the robustly stabilizing conditions for state feedback stabilization and design packet-loss dependent controllers by solving some matrix inequalities. A numerical example and some simulations are worked out to demonstrate the effectiveness of the proposed design method.

Gendered perceptions of experiential value in using web-based retail channels

Purpose – This paper compares the experiential consumption values that motivate consumer choice to purchase online for both male and female purchasers and non-purchasers. Design/methodology/approach – Using the theory of consumption value the study examines gendered perceptions of the functional, social and conditional value of using a virtual consumption setting for purchasing. Data was collected through an online survey and analysed using multiple discriminant analysis to determine meaningful differences between male and female purchasers and non-purchasers. Findings – The findings show that male online purchasers are discriminated from female purchasers by social value and from male non-purchasers by conditional value. Female purchasers are discriminated from male purchasers by functional value and from female non-purchasers by social value. Female non-purchasers are discriminated from female purchasers by conditional value. Male non-purchasers are discriminated from male purchasers by functional and social value. Research limitations/implications – Limitations include using an Internet survey and an Australian sample which may impact the generalisability of the findings to a wider population of Internet users. Future research should involve replication of the study in a country more or less developed in terms of gender composition of internet users to extend the generalisability of the findings. Additionally, researchers should examine whether other dimensions of consumption value,such as social influence through on- and off-line communication networks, may influence consumer choice to purchase online. Practical implications – The study provides practical implications for marketers to leverage consumption values that influence male and female consumers’ choice to purchase online and then drive their behaviour online through integrated marketing campaigns that involve both on- and offline strategies. Originality/value – The research makes an original contribution to the consumer behaviour literature as to date, no research has been found that undertakes such a comprehensive gender-based comparison of the perceived value of using a virtual consumption setting for purchasing.

Characterising anomalous events using change point correlation on unsolicited network traffic

Monitoring unused or dark IP addresses offers opportunities to extract useful information about both on-going and new attack patterns. In recent years, different techniques have been used to analyze such traffic including sequential analysis where a change in traffic behavior, for example change in mean, is used as an indication of malicious activity. Change points themselves say little about detected change; further data processing is necessary for the extraction of useful information and to identify the exact cause of the detected change which is limited due to the size and nature of observed traffic. In this paper, we address the problem of analyzing a large volume of such traffic by correlating change points identified in different traffic parameters. The significance of the proposed technique is two-fold. Firstly, automatic extraction of information related to change points by correlating change points detected across multiple traffic parameters. Secondly, validation of the detected change point by the simultaneous presence of another change point in a different parameter. Using a real network trace collected from unused IP addresses, we demonstrate that the proposed technique enables us to not only validate the change point but also extract useful information about the causes of change points.

Crossing the cultural divide : a contemporary holistic framework for conceptualising design studio education

While the studio is widely accepted as the learning environment where architecture students most effectively learn how to design (Mahgoub, 2007:195), there are surprisingly few studies that attempt to identify in a qualitative way the interrelated factors that contribute to and support design studio learning (Bose, 2007:131). Such a situation seems problematic given the changes and challenges facing education including design education. Overall, there is growing support for re-examining (perhaps redefining) the design studio particularly in response to the impact of new technologies but as this paper argues this should not occur independently of the other elements and qualities comprising the design studio. In this respect, this paper describes a framework developed for a doctoral project concerned with capturing and more holistically understanding the complexity and potential of the design studio to operate within an increasingly and largely unpredictable global context. Integral to this is a comparative analysis of selected cases underpinned by grounded theory methodology of the traditional design studio and the virtual design studio informed by emerging pedagogical theory and the experiences of those most intimately involved – students and lecturers. In addition to providing a conceptual model for future research, the framework is of value to educators currently interested in developing as well as evaluating learning environments for design.

Detection and prevention of distributed denial of services attacks by collaborative effort of software agents, first prototype implementation

Distributed Denial of Services DDoS, attacks has become one of the biggest threats for resources over Internet. Purpose of these attacks is to make servers deny from providing services to legitimate users. These attacks are also used for occupying media bandwidth. Currently intrusion detection systems can just detect the attacks but cannot prevent / track the location of intruders. Some schemes also prevent the attacks by simply discarding attack packets, which saves victim from attack, but still network bandwidth is wasted. In our opinion, DDoS requires a distributed solution to save wastage of resources. The paper, presents a system that helps us not only in detecting such attacks but also helps in tracing and blocking (to save the bandwidth as well) the multiple intruders using Intelligent Software Agents. The system gives dynamic response and can be integrated with the existing network defense systems without disturbing existing Internet model. We have implemented an agent based networking monitoring system in this regard.

Evaluation of distributed control signaling protocols in GMPLS

GMPLS is a generalized form of MPLS (MultiProtocol Label Switching). MPLS is IP packet based and it uses MPLS-TE for Packet Traffic Engineering. GMPLS is extension to MPLS capabilities. It provides separation between transmission, control and management plane and network management. Control plane allows various applications like traffic engineering, service provisioning, and differentiated services. GMPLS control plane architecture includes signaling (RSVP-TE, CR-LDP) and routing (OSPF-TE, ISIS-TE) protocols. This paper provides an overview of the signaling protocols, describes their main functionalities, and provides a general evaluation of both the protocols.

Use of IP addresses for high rate flooding attack detection

High-rate flooding attacks (aka Distributed Denial of Service or DDoS attacks) continue to constitute a pernicious threat within the Internet domain. In this work we demonstrate how using packet source IP addresses coupled with a change-point analysis of the rate of arrival of new IP addresses may be sufficient to detect the onset of a high-rate flooding attack. Importantly, minimizing the number of features to be examined, directly addresses the issue of scalability of the detection process to higher network speeds. Using a proof of concept implementation we have shown how pre-onset IP addresses can be efficiently represented using a bit vector and used to modify a “white list” filter in a firewall as part of the mitigation strategy.

Reinforcing bad behaviour : the misuse of security indicators on popular websites

Before making a security or privacy decision, Internet users should evaluate several security indicators in their browser, such as the use of HTTPS (indicated via the lock icon), the domain name of the site, and information from extended validation certificates. However, studies have shown that human subjects infrequently employ these indicators, relying on other indicators that can be spoofed and convey no cryptographic assurances. We identify four simple security indicators that accurately represent security properties of the connection and then examine 125 popular websites to determine if the sites' designs result in correctly displayed security indicators during login. In the vast majority of cases, at least some security indicators are absent or suboptimal. This suggests users are becoming habituated to ignoring recommended security indicators.

Centrally supported online surveys for research at QUT

We describe the introduction, service growth, benefits and holistic support approach of a centrally supported universitywide online survey tool for researchers at QUT. The online survey service employs the Key Survey software, and has grown into a significant service for QUT researchers since being introduced in 2009. Key benefits of the approach include the ability of QUT to handle important issues relating to data such as security, privacy, integrity, archiving & disposal. The service also incorporates a workflow process that enhances the institution’s ability to ensure survey quality control through controlled approval and pilot testing before any survey is widely released. An important issue is that a tool like this can make it very easy to do very poor research very quickly while creating lots of data, due to the absence of a rigorous methodology designed to reduce errors and collect accurate, comprehensive, timely data. With this in mind, a holistic approach to service provision and support has been taken, which has included the introduction of an integrated system of seminars, tools and workshops to get researchers thinking about the quality of their research while becoming operational quickly. The system of seminars, workshops, checks and approvals we have put in place at QUT is designed to ensure better quality outcomes for QUT’s research and the individual researchers concerned.

How HCI design influences web security decisions

Even though security protocols are designed to make computer communication secure, it is widely known that there is potential for security breakdowns at the human machine interface. This paper reports on a diary study conducted in order to investigate what people identify as security decisions that they make while using the web. The study aimed to uncover how security is perceived in the individual's context of use. From this data, themes were drawn, with a focus on addressing security goals such as confidentiality and authentication. This study is the first study investigating users' web usage focusing on their self-documented perceptions of security and the security choices they made in their own environment.

Use of IEEE 1588-2008 for a sampled value process bus in transmission substations

IEC Technical Committee 57 (TC57) published a series of standards and technical reports for “Communication networks and systems for power utility automation” as the IEC 61850 series. Sampled value (SV) process buses allow for the removal of potentially lethal voltages and damaging currents inside substation control rooms and marshalling kiosks, reduce the amount of cabling required in substations, and facilitate the adoption of non-conventional instrument transformers. IEC 61850-9-2 provides an inter-operable solution to support multi-vendor process bus solutions. A time synchronisation system is required for a SV process bus, however the details are not defined in IEC 61850-9-2. IEEE Std 1588-2008, Precision Time Protocol version 2 (PTPv2), provides the greatest accuracy of network based time transfer systems, with timing errors of less than 100 ns achievable. PTPv2 is proposed by the IEC Smart Grid Strategy Group to synchronise IEC 61850 based substation automation systems. IEC 61850-9-2, PTPv2 and Ethernet are three complementary protocols that together define the future of sampled value digital process connections in substations. The suitability of PTPv2 for use with SV is evaluated, with preliminary results indicating that steady state performance is acceptable (jitter < 300 ns), and that extremely stable grandmaster oscillators are required to ensure SV timing requirements are met when recovering from loss of external synchronisation (such as GPS).

Network protocols and predictive control strategies for distributed real-time control applications

A trend in design and implementation of modern industrial automation systems is to integrate computing, communication and control into a unified framework at different levels of machine/factory operations and information processing. These distributed control systems are referred to as networked control systems (NCSs). They are composed of sensors, actuators, and controllers interconnected over communication networks. As most of communication networks are not designed for NCS applications, the communication requirements of NCSs may be not satisfied. For example, traditional control systems require the data to be accurate, timely and lossless. However, because of random transmission delays and packet losses, the control performance of a control system may be badly deteriorated, and the control system rendered unstable. The main challenge of NCS design is to both maintain and improve stable control performance of an NCS. To achieve this, communication and control methodologies have to be designed. In recent decades, Ethernet and 802.11 networks have been introduced in control networks and have even replaced traditional fieldbus productions in some real-time control applications, because of their high bandwidth and good interoperability. As Ethernet and 802.11 networks are not designed for distributed control applications, two aspects of NCS research need to be addressed to make these communication networks suitable for control systems in industrial environments. From the perspective of networking, communication protocols need to be designed to satisfy communication requirements for NCSs such as real-time communication and high-precision clock consistency requirements. From the perspective of control, methods to compensate for network-induced delays and packet losses are important for NCS design. To make Ethernet-based and 802.11 networks suitable for distributed control applications, this thesis develops a high-precision relative clock synchronisation protocol and an analytical model for analysing the real-time performance of 802.11 networks, and designs a new predictive compensation method. Firstly, a hybrid NCS simulation environment based on the NS-2 simulator is designed and implemented. Secondly, a high-precision relative clock synchronization protocol is designed and implemented. Thirdly, transmission delays in 802.11 networks for soft-real-time control applications are modeled by use of a Markov chain model in which real-time Quality-of- Service parameters are analysed under a periodic traffic pattern. By using a Markov chain model, we can accurately model the tradeoff between real-time performance and throughput performance. Furthermore, a cross-layer optimisation scheme, featuring application-layer flow rate adaptation, is designed to achieve the tradeoff between certain real-time and throughput performance characteristics in a typical NCS scenario with wireless local area network. Fourthly, as a co-design approach for both a network and a controller, a new predictive compensation method for variable delay and packet loss in NCSs is designed, where simultaneous end-to-end delays and packet losses during packet transmissions from sensors to actuators is tackled. The effectiveness of the proposed predictive compensation approach is demonstrated using our hybrid NCS simulation environment.