570 research outputs found

    A Survey on Handover Management in Mobility Architectures

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    This work presents a comprehensive and structured taxonomy of available techniques for managing the handover process in mobility architectures. Representative works from the existing literature have been divided into appropriate categories, based on their ability to support horizontal handovers, vertical handovers and multihoming. We describe approaches designed to work on the current Internet (i.e. IPv4-based networks), as well as those that have been devised for the "future" Internet (e.g. IPv6-based networks and extensions). Quantitative measures and qualitative indicators are also presented and used to evaluate and compare the examined approaches. This critical review provides some valuable guidelines and suggestions for designing and developing mobility architectures, including some practical expedients (e.g. those required in the current Internet environment), aimed to cope with the presence of NAT/firewalls and to provide support to legacy systems and several communication protocols working at the application layer

    Advanced Strain-Isolation-Pad Material with Bonded Fibrous Construction

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    The feasibility of utilizing air lay and liquid lay felt deposition techniques to fabricate strain isolation pad (SIP) materials for the Space Shuttle Orbiter was demonstrated. These materials were developed as candidate replacements for the present needled felt SIP used between the ceramic tiles and the aluminum skin on the undersurface of the Orbiter. The SIP materials that were developed consisted of high temperature aramid fibers deposited by controlled fluid (air or liquid) carriers to form low density unbonded felts. The deposited felts were then bonded at the fiber intersections with a small amount of high temperature polyimide resin. This type of bonded felt construction can potentially eliminate two of the problems associated with the present SIP, viz., transmittal of localized stresses into the tiles and load history dependent mechanical response. However, further work is needed to achieve adequate through thickness tensile strength in the bonded felts

    Development of a communication environment between IPv6 and IPv4

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    The aim of this paper is to present the design, specification, implementation and testing of a demonstration environment for examining a genuinely new communication technique. This technique ensures that 3G mobile networks can communicate with legacy Internet phones. More than one levels of the TCP/IP protocol family are necessary for the communication, so we had to develop device drivers and user level applications too. The different levels require various development techniques and tools, whose efficiently combined usage is emphasized

    Traversing NAT: A Problem

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    This quasi-experimental before-and-after study measured and analyzed the impacts of adding security to a new bi-directional Network Address Translation (NAT). Literature revolves around various types of NAT, their advantages and disadvantages, their security models, and networking technologies’ adoption. The study of the newly created secure bi-directional model of NAT showed statistically significant changes in the variables than another model using port forwarding. Future research of how data will traverse networks is crucial in an ever-changing world of technology

    Mobility Support in User-Centric Networks

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    In this paper, an overview of challenges and requirements for mobility management in user-centric networks is given, and a new distributed and dynamic per-application mobility management solution is presented. After a brief summary of generic mobility management concepts, existing approaches from the distributed and peer-to-peer mobility management literature are introduced, along with their applicability or shortcomings in the UCN environment. Possible approaches to deal with the decentralized and highly dynamic nature of UCNs are also provided with a discussion and an introduction to potential future work

    Network Address Translation (NAT) Behavioral Requirements for Unicast UDP

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    DSL-Lab: a Low-power Lightweight Platform to Experiment on Domestic Broadband Internet

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    International audienceThis article presents the design and building of DSL-Lab, a platform to experiment on distributed computing over broadband domestic Internet. Experimental platforms such as PlanetLab and Grid'5000 are promising methodological approaches to study distributed systems. However, both platforms focus on high-end service and network deployments only available on a restricted part of the Internet, leaving aside the possibility for researchers to experiment in conditions close to what is usually available with domestic connection to the Internet. DSL-Lab is a complementary approach to PlanetLab and Grid'5000 to experiment with distributed computing in an environment closer to how Internet appears, when applications are run on end-user PCs. DSL-Lab is a set of 40 low-power and low-noise nodes, which are hosted by participants, using the participants' xDSL or cable access to the Internet. The objective is to provide a validation and experimentation platform for new protocols, services, simulators and emulators for these systems. In this paper, we report on the software design (security, resources allocation, power management) as well as on the first experiments achieved

    Towards cloud-aware policy enforcement with universal cloud classification as a service (UCCaaS) in software defined networks

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    Network services are a critical component of today's networks. They apply critical functions (e.g. security, routing or quality of service) to traffic to enhance the network operators and application consumers experience. Today these services are inserted physically on the data-forwarding plane without providing much flexibility to deal with different traffic types or affiliations. Cloud Computing, however, demands policy enforcement on a per-Provider, per-Service and/or per-Tenant basis. In addition, there is an increasing need for dynamic transparent network chaining independent of the underlying transport infrastructure. We first introduce the concept of Universal Cloud Classification as a Service (UCCaaS). Followed by highlighting how it can be leveraged in conjunction with Network Service Headers (NSH) to address above challenges. UCC provides an addressing scheme to isolate traffic streams on a per-provider, per-service and/or per-tenant basis. To enable bi-directional policy enforcement in network functions we extend the UCC proposal by adding source and destination support. NSH is a way to steer network traffic dynamically across a set of network functions. We demonstrate the feasibility and advantages of our UCCaaS + NSH proposal with an example application, where a service chain defines Access Control Lists and traffic rate limiting on a per-Service and per-Tenant basis. Our proposal opens a door for a wide range of cloud-aware network services and functions
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