125 research outputs found
Transparent and scalable client-side server selection using netlets
Replication of web content in the Internet has been found to improve service response time, performance and reliability offered by web services. When working with such distributed server systems, the location of servers with respect to client nodes is found to affect service response time perceived by clients in addition to server load conditions. This is due to the characteristics of the network path segments through which client requests get routed. Hence, a number of researchers have advocated making server selection decisions at the client-side of the network. In this paper, we present a transparent approach for client-side server selection in the Internet using Netlet services. Netlets are autonomous, nomadic mobile software components which persist and roam in the network independently, providing predefined network services. In this application, Netlet based services embedded with intelligence to support server selection are deployed by servers close to potential client communities to setup dynamic service decision points within the network. An anycast address is used to identify available distributed decision points in the network. Each service decision point transparently directs client requests to the best performing server based on its in-built intelligence supported by real-time measurements from probes sent by the Netlet to each server. It is shown that the resulting system provides a client-side server selection solution which is server-customisable, scalable and fault transparent
IPv6 : prospects and problems : a technical and management investigation into the deployment of IPv6
Masteroppgave i informasjons- og kommunikasjonsteknologi 2003 - Høgskolen i Agder, GrimstadIPv4 has been used for over twenty years, and will most likely be used in many years ahead.
However, we are now experiencing that the IPv4 address space is running out, resulting in
restrictions on who will be able to get these types of addresses assigned to them. Methods
such as Network Address Translator (NAT) have been developed and implemented in order to
save the IPv4 address space. It is said that this is not a good enough solution, as such
techniques introduce new problems at the same time solving some.
A new version of the Internet Protocol, IPv6, has been developed and is likely to replace
IPv4. IPv6 has been developed to solve the address problem, but also new features are
designed to supposedly enhance network traffic.
In our thesis we give an overview of the problems with IPv4. This includes the limited
address space and the limited quality of service. Further we present the features of IPv6 that
are meant to solve these problems and add new possibilities. These are: New address format,
the IPv6 header and Extension headers to mention some.
Further we have investigated and here present how the transition from IPv4 to IPv6 is
expected to take place, followed by a thorough description of the transition mechanisms. One
of the original intentions on the development of IPv6 was that IPv4 and IPv6 have to be able
to coexist for a long period of time. Transition mechanisms have therefore been designed to
make this possible. There are three main types of mechanisms:
- Tunnelling
- Translation
- Dual-stack.
Each of these mechanisms requires different configuration and implementations in hosts and
network.
Technical research on transition mechanisms states that these are not good enough for all
IPv6/IPv4 scenarios and need improvements in order to make IPv4 and IPv6 coexist
smoothly. There are a lot of transition mechanisms that are agreed upon as being good for
general use and then there are transition mechanisms that are good for certain scenarios and
not for others. Some scenarios still lack a good translation mechanism. As a result of this,
IPv6 networks are being built separately from IPv4 networks. In Asia commercial IPv6
networks are offered, while the process is slower in other parts of the world. The reasons for
not building IPv6 networks are many, and not agreed upon. Some believe it is because of
economical restrictions, while others claim it is technical reasons and that it exists far too few
applications supporting IPv6. The number of IPv6 enabled applications is growing. Large
companies like; Microsoft Corporation, Cisco Systems Inc, Apple Computers Inc., Sun
Microsystems Inc and various versions of Linux include support for IPv6.
The deployment of IPv6 is expected to happen at different times in different parts of the
world. We have investigated the status of IPv6 globally and in Norway. The main results are that the roll-out has reached the furthest in Asia where commercial IPv6 networks already are
offered. The activity in Norway is still small, but growing.
It was desired to run an experiment in order to prove or disprove some of the information we
gathered on how IPv6 interoperates with IPv4, but because of limitations in the network at
Heriot-Watt University we were not able to do this. Instead we have focused on a project by
Telenor R&D; “IPv6 migration of unmanaged networks-The Tromsø IPv6 Pilot”. We also
gathered some information from people working at Norwegian ISPs in order to address some
of the aspects of the upgrading
Psychopower and Ordinary Madness: Reticulated Dividuals in Cognitive Capitalism
Despite the seemingly neutral vantage of using nature for widely-distributed computational purposes, neither post-biological nor post-humanist teleology simply concludes with the real "end of nature" as entailed in the loss of the specific ontological status embedded in the identifier "natural." As evinced by the ecological crises of the Anthropocene—of which the 2019 Brazil Amazon rainforest fires are only the most recent—our epoch has transfixed the “natural order" and imposed entropic artificial integration, producing living species that become “anoetic,” made to serve as automated exosomatic residues, or digital flecks. I further develop Gilles Deleuze’s description of control societies to upturn Foucauldian biopower, replacing its spacio-temporal bounds with the exographic excesses in psycho-power; culling and further detailing Bernard Stiegler’s framework of transindividuation and hyper-control, I examine how becoming-subject is predictively facilitated within cognitive capitalism and what Alexander Galloway terms “deep digitality.” Despite the loss of material vestiges qua virtualization—which I seek to trace in an historical review of industrialization to postindustrialization—the drive-based and reticulated "internet of things" facilitates a closed loop from within the brain to the outside environment, such that the aperture of thought is mediated and compressed. The human brain, understood through its material constitution, is susceptible to total datafication’s laminated process of “becoming-mnemotechnical,” and, as neuroplasticity is now a valid description for deep-learning and neural nets, we are privy to the rebirth of the once-discounted metaphor of the “cybernetic brain.” Probing algorithmic governmentality while posing noetic dreaming as both technical and pharmacological, I seek to analyze how spirit is blithely confounded with machine-thinking’s gelatinous cognition, as prosthetic organ-adaptation becomes probabilistically molded, networked, and agentially inflected (rather than simply externalized)
D3.6.1: Cookbook for IPv6 Renumbering in SOHO and Backbone Networks
In this text we present the results of a set of experiments that are designed to be a first step in the process of analysing how effective network renumbering procedures may be in the context of IPv6. An IPv6 site will need to get provider assigned (PA) address space from its upstream ISP. Because provider independent (PI) address space is not available for IPv6, a site wishing to change provider will need to renumber from its old network prefix to the new one. We look at the scenarios, issues and enablers for such renumbering, and present results and initial conclusions and recommendations in the context of SOHO and backbone networking. A subsequent deliverable (D3.6.2) will refine these findings, adding additional results and context from enterprise and ISP renumbering scenarios
Pro-collaborative mobile systems in next generation IP networks
Computing system designs of today take on either the interactive or the proactive
form. Motivated by the user’s desire to make his/her computing experience more
intelligent and personalised, the progression from interactive (human-centred) to
proactive (human-supervised) is evident. It can be observed that current research
mainly emphasises the user as the dominant focus of a user-system interaction.
Consider a model that we called the opponent-process model. It contains two
processes, one representing the user and the other the system, where both processes
are capable of dominating each other, though working collaboratively towards a
predefined task. We argue the necessity to design computing systems which are
balanced in this model, such that the system process, at times, becomes the dominant
process. We refer to this as the pro-collaborative design form.
We dissect mobility into the notion of a nomadic user and the notion of a
nomadic system. The examination into the nomadic user problem space reveals the
potential for applying the pro-collaborative approach in optimising handoff
management. Significant performance advantages can be obtained with our proposed
S-MIP framework, based on the pro-collaborative design, when compared with
established handoff latency optimisation schemes. The key differentiator lies in its
indicative approach in addressing handoff ambiguity. Instead of passively
anticipating through prediction as to when a mobile user might cross network
boundaries (user-dominant), the system actively indicates to the user when, where
and how to handoff (system-dominant). This eliminates the handoff ambiguity.
Regarding the notion of a nomadic system, that is, the ability to move services
offered by computing systems to arbitrary points in the Internet, we explore the idea
of the dynamic extension of network services to a mobile user on-demand. Based on
the pro-collaborative form, we develop the METAMORPHOSE architecture which
facilitates such a dynamic service extension. By assuming the proliferation of
programmable network switches and computational resources within the Internet, we
re-examine how ‘loose’ service agreements between network services providers can
be, to achieve such borderless moving-service offerings.
The viability of the pro-collaborative form is reflected through our design and
implementation of protocols and architectures which address the notion of nomadic
user and nomadic system
A session-based architecture for Internet mobility
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2003.Includes bibliographical references (p. 179-189).The proliferation of mobile computing devices and wireless networking products over the past decade has led to an increasingly nomadic computing lifestyle. A computer is no longer an immobile, gargantuan machine that remains in one place for the lifetime of its operation. Today's personal computing devices are portable, and Internet access is becoming ubiquitous. A well-traveled laptop user might use half a dozen different networks throughout the course of a day: a cable modem from home, wide-area wireless on the commute, wired Ethernet at the office, a Bluetooth network in the car, and a wireless, local-area network at the airport or the neighborhood coffee shop. Mobile hosts are prone to frequent, unexpected disconnections that vary greatly in duration. Despite the prevalence of these multi-homed mobile devices, today's operating systems on both mobile hosts and fixed Internet servers lack fine-grained support for network applications on intermittently connected hosts. We argue that network communication is well-modeled by a session abstraction, and present Migrate, an architecture based on system support for a flexible session primitive. Migrate works with application-selected naming services to enable seamless, mobile "suspend/resume" operation of legacy applications and provide enhanced functionality for mobile-aware, session-based network applications, enabling adaptive operation of mobile clients and allowing Internet servers to support large numbers of intermittently connected sessions. We describe our UNIX-based implementation of Migrate and show that sessions are a flexible, robust, and efficient way to manage mobile end points, even for legacy applications.(cont.) In addition, we demonstrate two popular Internet servers that have been extended to leverage our novel notion of session continuations to enable support for large numbers of suspended clients with only minimal resource impact. Experimental results show that Migrate introduces only minor throughput degradation (less than 2% for moderate block sizes) when used over popular access link technologies, gracefully detects and suspends disconnected sessions, rapidly resumes from suspension, and integrates well with existing applications.by Mark Alexander Connell Snoeren.Ph.D
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