On the Scalability of Addressing in Private Networks Using RPX

In recent times, the imminent lack of public IPv4 addresses has attracted the attention of both research community and industry. The cellular industry has decided to combat this problem by using IPv6 for all new terminals. However, the success of 3G network deployment will depend on the services offered to end users. Currently, almost all services reside in the public IPv4 address space, making them inaccessible to users in IPv6 networks. Thus, an intermediate translation mechanism is required. Previous studies on network address translation methods have shown that REBEKAH-IP with Port Extension (RPX) supports all types of services that can be offered to IPv6 terminals from the public IPv4 based Internet, and provides excellent scalability. However, this method suffers from an ambiguity problem which may lead to call blocking. In this paper, we present an improvement to RPX scheme in which the side effect is removed and fully scalable system. We firstly show the expected number of public IPv4 addresses utilization to the DNS of RPX server. This utilization is computed in terms of the probability of socket open requests from mobile terminals, the probability of call blocking and the estimated number of mobile terminals at the network initialization phase. The mathematical model is also provided as a guideline to determine the range of public IPv4 addresses allocated to an RPX gateway in a cellular network. In addition, the results are presented through a set of simulations. However, we proposed the RPX scheme to use a simple round robin scheduling algorithm is sub-optimal in terms of call blocking probability and further propose to use a priority queue algorithm to improve the scalability. In addition, we present extensive simulation results on the practical scalability of RPX with different traffic compositions to provide a guideline of the expected scalability in large-scale networks such as 3G networks

Using virtual worlds as collaborative environments for innovation and design: lessons learned and observations from case studies in architectural projects

In this paper we discuss observations and lessons learned in conducting architectural design projects in virtual worlds. By integrating a community of users in virtual worlds into a collaborative architectural design process, organisations can tap the community's creativity and intelligence through immersive technology. The paper provides an overview of the latest advances of information and communication technologies in immersive virtual environments and discusses some of the observations and lessons learned which should be taken into account in developing collaboration models for such activities. Here we propose four modes of collaboration, based on the choices for degree of openness and governance structure, which are illustrated by four case studies

How do you make yourself a theatre without organs? Deleuze, Artaud and the concept of differential presence

This article provides an exposition of four key concepts emerging in the encounter between the philosophical man of the theatre, Antonin Artaud, and the theatrical philosopher, Gilles Deleuze: the body without organs, the theatre without organs, the destratified voice and differential presence. The article proposes that Artaud's 1947 censored radio play To Have Done with the Judgment of God constitutes an instance of a theatre without organs that uses the destratified voice in a pursuit of differential presence – as a nonrepresentative encounter with difference that forces new thoughts upon us. Drawing from various works by Deleuze, including Difference and Repetition, The Logic of Sense, A Thousand Plateaus and ‘One Less Manifesto’, I conceive differential presence as an encounter with difference, or perpetual variation, as that which exceeds the representational consciousness of a subject, forcing thought through rupture rather than communicating meanings through sameness. Contra the dismissal of Artaud's project as paradoxical or impossible, the article suggests that his nonrepresentational theatre seeks to affirm a new kind of presence as difference, rather than aiming to transcend difference in order to reach the self-identical presence of Western metaphysics

The Future of the Internet III

Presents survey results on technology experts' predictions on the Internet's social, political, and economic impact as of 2020, including its effects on integrity and tolerance, intellectual property law, and the division between personal and work lives

IPv6 Network Mobility

Network Authentication, Authorization, and Accounting has been used since before the days of the Internet as we know it today. Authentication asks the question, “Who or what are you?” Authorization asks, “What are you allowed to do?” And fi nally, accounting wants to know, “What did you do?” These fundamental security building blocks are being used in expanded ways today. The fi rst part of this two-part series focused on the overall concepts of AAA, the elements involved in AAA communications, and highlevel approaches to achieving specifi c AAA goals. It was published in IPJ Volume 10, No. 1[0]. This second part of the series discusses the protocols involved, specifi c applications of AAA, and considerations for the future of AAA

Interactive Real-Time Embedded Systems Education Infused with Applied Internet Telephony

The transition from traditional circuit-switched phone systems to modern packet-based Internet telephony networks demands tools to support Voice over Internet Protocol (VoIP) development. In this paper, we introduce the XinuPhone, an integrated hardware/software approach for educating users about VoIP technology on a real-time embedded platform. We propose modular course topics for design-oriented, hands-on laboratory exercises: filter design, timing, serial communications, interrupts and resource budgeting, network transmission, and system benchmarking. Our open-source software platform encourages development and testing of new CODECs alongside existing standards, unlike similar commercial solutions. Furthermore, the supporting hardware features inexpensive, readily available components designed specifically for educational and research users on a limited budget. The XinuPhone is especially good for experimenting with design trade-offs as well as interactions between real-time software and hardware components