IMDEA Networks Institute Digital Repository
Not a member yet
1915 research outputs found
Sort by
An IPv6 Distributed Client Mobility Management approach using existing mechanisms
No full textInternet-Draft
Intended status: Informational
Expires: January 14, 2014The use of centralized mobility management approaches -- such as Mobile IPv6 -- poses some difficulties to operators of current and future networks, due to the expected large number of mobile users and their exigent demands. All this has triggered the need for distributed mobility management alternatives, that alleviate operators' concerns allowing for cheaper and more efficient network deployments.
This draft describes a possible way of achieving a distributed mobility behavior with Client Mobile IP, based on Mobile IPv6 and the use of Cryptographic Generated Addresses.pu
Consistent Packet Processing - Because Consistent Updates Are Not Enough
Get PDFIn this poster and demo, we showcase a new class of problems that can occur due to inconsistent packet processing at an OpenFlow controller. We proceed to outline a potential solution.TRUEpu
Modelling and Real-Trace-Based Evaluation of Static and Dynamic Coalescing for Energy Efficient Ethernet
Get PDFThe IEEE Standard 802.3az, namely Energy Efficient Ether- net (EEE), has been recently introduced to reduce the power consumed in LANs. Since then, researchers have proposed various traffic shaping techniques to leverage EEE in order to boost power saving. In particular, packet coalescing is
a promising mechanism which can be used on top of EEE to tradeoff power saving and packet delay. In this paper, we analyze the interesting and special case of 1000Base-T EEE links, in which power saving operations are triggered only when links are inactive in both transmission directions. We are the first to provide an analytical model for EEE 1000Base-T which accounts for the bidirectional nature of LAN traffic. Our model allows to compute the power saving achieved by EEE, with and without packet coalescing, by using a few significant traffic descriptors. Furthermore, we use real traffic traces to investigate on the performance of static as well as dynamic coalescing schemes. Our results show that dynamic coalescing does not significantly outper- form static coalescing in terms of power save and delay.MICINN grant TEC2011-29688-C02-01TRUEpu
Impact of Mobility on the Performance of Context-Aware Applications Using Floating Content
Get PDFThe growth of mobile computing and the evolution of smart user devices are progressively driving applications towards “context- awareness”, i.e., towards behaviors that change according to variations in context. Such applications use information that is restricted in space and time, making their communication requirements very different from those of conventional applications, so that opportunistic schemes are better suited to this case than more conventional communications. In this work we consider an opportunistic communication scheme called “Floating Content” (FC), which was specifically designed for server-less distributed context-aware applications, and we refine our previous inves- tigation of the viability of FC for context-aware mobile applications, by considering the impact of different mobility models on the performance of FC. In particular, we consider four different mobility models, and, by using extensive simulation experiments, we investigate the performance of three different categories of context-aware applications that use FC. We also compare the simulation results to the performance predictions of our previously proposed simple analytical model. Results show that good performance can be achieved in content distribution by using FC under a variety of mobility models. They also show that a simple analyt- ical model can provide useful performance predictions even for complex and realistic mobility models, although some application-specific char- acteristics might call for specialized models to improve the accuracy of performance estimates.TRUEpu
The BGP Visibility Scanner
Get PDFBy tweaking the BGP configurations, the network
operators are able to express their interdomain routing preferences, designed to accommodate a myriad goals. Given the complex interactions between policies in the Internet, the origin AS by itself cannot ensure that only by configuring a routing policy it can also achieve the anticipated results. Moreover, the definition of routing policies is a complicated process, involving a number of subtle tuning operations prone to errors. In this paper, we propose the BGP Visibility Scanner which allows network operators to validate the correct implementation of their
routing policies, by corroborating the BGP routing information from approximatively 130 independent observation points in the Internet. We exemplify the use of the proposed methodology and also perform an initial validation for the BGP Visibility Scanner capabilities through various real operational use cases.TRUEpu
Adaptive Modulation for Finite Horizon Multicasting of Erasure-coded Data
Get PDFWe design an adaptive modulation scheme to support
opportunistic multicast scheduling in wireless networks.
Whereas prior work optimizes capacity, we investigate the finite horizon problem where (once or repeatedly) a fixed number of packets has to be transmitted to a set of wireless receivers in the shortest amount of time – a common problem, e.g., for software updates or video multicast. In the finite horizon problem, the optimum coding and modulation schemes critically depend on the recent reception history of the receivers and require a fine balance between maximizing overall throughput and equalizing individual receiver throughput. We formulate a dynamic programming algorithm that optimally solves this scheduling problem. We then develop two low complexity heuristics that perform very close to the optimal solution and are suitable for practical online scheduling in base stations. We further analyze the performance of our algorithms by means of simulation in a wide range of wireless scenarios. They substantially outperform existing solutions based on throughput maximization or favoring the user with the worst channel, and we obtain a 35% performance improvement over the former and a 100% improvement over the latter in a scenario with Rayleigh fading.TRUEpu
Building an HLA-based distributed simulation: a metadata approach
Get PDFConference Proceedings, pp. 153-160, 2013. ISBN 978-0-7695-5138-8Building complex simulations is usually a challenge, mainly due to the broad spectrum of concepts that must be taken into account. Simulation middleware based on the IEEE 1516 standard tries to reduce this complexity, but there are still aspects that hinder the implementation of such simulations. The dependency between the source code and the corresponding formal description of the model could be hard to verify and maintain. Also, the code for the model simulation and the code needed for the integration with the HLA/RTI middleware coexist becoming complex and error prone. In this paper we propose a new framework based on metadata (Java annotations or C# attributes) that faces these problems and extends the IEEE 1516-2010 standard. In addition, we present an implementation of the IEEE 1516 standard in the C# language. Finally, we explain our experience in implementing the standard in C#.TRUEpu
Implementations details of the IEEE 802.11aa Group Addressed Transmission Service
Get PDFIn this report we explain and describe the implementation of the 802.11aa protocol and every aspect that concerns the choices selected and their motivations. We detail all the required modifications at the driver and firmware levels. We also motivate the choice of the implementation platform.pu