Performance modelling of a multiple threshold RED mechanism for bursty and correlated Internet traffic with MMPP arrival process

Access to the large web content hosted all over the world by users of the Internet engage many hosts, routers/switches and faster links. They challenge the internet backbone to operate at its capacity to assure e±cient content access. This may result in congestion and raises concerns over various Quality of Service (QoS) issues like high delays, high packet loss and low throughput of the system for various Internet applications. Thus, there is a need to develop effective congestion control mechanisms in order to meet various Quality of Service (QoS) related performance parameters. In this paper, our emphasis is on the Active Queue Management (AQM) mechanisms, particularly Random Early Detection (RED). We propose a threshold based novel analytical model based on standard RED mechanism. Various numerical examples are presented for Internet traffic scenarios containing both the burstiness and correlation properties of the network traffic

Machine learning for early detection of traffic congestion using public transport traffic data

The purpose of this project is to provide better knowledge of how the bus travel times is affected by congestion and other problems in the urban traffic environment. The main source of data for this study is second-level measurements coming from all buses in the Linköping region showing the location of each vehicle.The main goal of this thesis is to propose, implement, test and optimize a machine learning algorithm based on data collected from regional buses from Sweden so that it is able to perform predictions on the future state of the urban traffic.El objetivo principal de este proyecto es proponer, implementar, probar y optimizar un algoritmo de aprendizaje automático basado en datos recopilados de autobuses regionales de Suecia para que poder realizar predicciones sobre el estado futuro del tráfico urbano.L'objectiu principal d'aquest projecte és proposar, implementar, provar i optimitzar un algoritme de machine learning basat en dades recollides a partir d'autobusos regionals de Suècia de manera per poder realitzar prediccions sobre l'estat futur del trànsit urbà

Scalable Peer-to-Peer Streaming for Live Entertainment Content

We present a system for streaming live entertainment content over the Internet originating from a single source to a scalable number of consumers without resorting to centralized or provider-provisioned resources. The system creates a peer-to-peer overlay network, which attempts to optimize use of existing capacity to ensure quality of service, delivering low startup delay and lag in playout of the live content. There are three main aspects of our solution: first, a swarming mechanism that constructs an overlay topology for minimizing propagation delays from the source to end consumers; second, a distributed overlay anycast system that uses a location-based search algorithm for peers to quickly find the closest peers in a given stream; and finally, a novel incentive mechanism that encourages peers to donate capacity even when the user is not actively consuming content

Understand Your Chains: Towards Performance Profile-based Network Service Management

Allocating resources to virtualized network functions and services to meet service level agreements is a challenging task for NFV management and orchestration systems. This becomes even more challenging when agile development methodologies, like DevOps, are applied. In such scenarios, management and orchestration systems are continuously facing new versions of functions and services which makes it hard to decide how much resources have to be allocated to them to provide the expected service performance. One solution for this problem is to support resource allocation decisions with performance behavior information obtained by profiling techniques applied to such network functions and services. In this position paper, we analyze and discuss the components needed to generate such performance behavior information within the NFV DevOps workflow. We also outline research questions that identify open issues and missing pieces for a fully integrated NFV profiling solution. Further, we introduce a novel profiling mechanism that is able to profile virtualized network functions and entire network service chains under different resource constraints before they are deployed on production infrastructure.Comment: Submitted to and accepted by the European Workshop on Software Defined Networks (EWSDN) 201

Efficient computational strategies for doubly intractable problems with applications to Bayesian social networks

Powerful ideas recently appeared in the literature are adjusted and combined to design improved samplers for Bayesian exponential random graph models. Different forms of adaptive Metropolis-Hastings proposals (vertical, horizontal and rectangular) are tested and combined with the Delayed rejection (DR) strategy with the aim of reducing the variance of the resulting Markov chain Monte Carlo estimators for a given computational time. In the examples treated in this paper the best combination, namely horizontal adaptation with delayed rejection, leads to a variance reduction that varies between 92% and 144% relative to the adaptive direction sampling approximate exchange algorithm of Caimo and Friel (2011). These results correspond to an increased performance which varies from 10% to 94% if we take simulation time into account. The highest improvements are obtained when highly correlated posterior distributions are considered.Comment: 23 pages, 8 figures. Accepted to appear in Statistics and Computin

Placing the Networks on the Web: Challenges and Opportunities for Managing in Developing Asia

Placing the networks on the Web poses a fundamental challenge, but also provides new opportunities for managing in Developing Asia. There is a huge efficiency gap between the region's manufacturing systems and the management of complementary, knowledge-intensive support services. The challenge is to reduce this gap as quickly as possible by embracing the Internet as a core business function, despite a weak base of accumulated knowledge of how to manage IT-based information systems. Asian companies, even the best, lag substantially behind their American and European counterparts. There is a potential vicious circle that needs to be broken: a belated transition to IT-based information systems has prevented the accumulation of knowledge, through trial-and-error, of how to design and implement an appropriate IT organization that reflects the peculiar strengths and weaknesses of diverse Asian management systems. Limited resources prevent any attempt to address these problems in a big leap forward. This implies that in-house efforts need to be supplemented with outsourcing of IT services. There is also a need for strategic partnering with major suppliers of Internet software and networking equipment. The opportunity is that the Internet provides almost unlimited opportunities for the outsourcing of mission-critical support services, such as ERP (enterprise resource planning), HRM (human resource management). Furthermore, fierce competition among major producers of Internet software and networking equipment has created a buyers' market - placing Asian firms in a reasonably strong bargaining position. These developments are generally not well covered by existing studies, which are primarily focused on developments in the U.S. and Europe. The paper tries to fill this gap, and explores how placing global production networks on the Web affects managing in Developing Asia. A conceptual framework is introduced in parts 1 to 3. That framework is then applied to one of the role models of managing in Asia, Taiwan's Acer Group. Part 1 introduces a taxonomy of expected benefits from Internet-enabled transformations of business organization. In part 2, we argue that the real issue is to analyze how the Internet reshapes the organization of global production networks. In part3, we access conflicting claims on how an increased use of the Internet to manage global production networks affects international knowledge diffusion. In part 4, the example of Taiwan's Acer Group is used to describe the challenge for Asian firms to embrace the Internet as a key management function. And in part 5, we ask what Acer's experience tells us about Developing Asia's opportunities.

Economic Development Potential through IP Telephony for Namibia

IP telephony, economic growth, telecommunications, ICT, Granger causality, Namibia