Spider III: A multi-agent-based distributed computing system

The project, Spider III, presents architecture and protocol of a multi-agent-based internet distributed computing system, which provides a convenient development and execution environment for transparent task distribution, load balancing, and fault tolerance. Spider is an on going distribution computing project in the Department of Computer Science, California State University San Bernardino. It was first proposed as an object-oriented distributed system by Han-Sheng Yuh in his master\u27s thesis in 1997. It has been further developed by Koping Wang in his master\u27s project, of where he made large contribution and implemented the Spider II System

On secure communication in integrated internet and heterogeneous multi-hop wireless networks.

Integration of the Internet with a Cellular Network, WMAN, WLAN, and MANET presents an exceptional promise by having co-existence of conventional WWANs/WMANs/WLANs with wireless ad hoc networks to provide ubiquitous communication. We call such integrated networks providing internet accessibility for mobile users as heterogeneous multi-hop wireless networks where the Internet and wireless infrastructure such as WLAN access points (APs) and base stations (BSs) constitute the backbone for various emerging wireless networks (e.g., multi-hop WLAN and ad hoc networks. Earlier approaches for the Internet connectivity either provide only unidirectional connectivity for ad hoc hosts or cause high overhead as well as delay for providing full bi-directional connections. In this dissertation, a new protocol is proposed for integrated Internet and ad hoc networks for supporting bi-directional global connectivity for ad hoc hosts. In order to provide efficient mobility management for mobile users in an integrated network, a mobility management protocol called multi-hop cellular IP (MCIP) has been proposed to provide a micro-mobility management framework for heterogeneous multi-hop network. The micro-mobility is achieved by differentiating the local domain from the global domain. At the same time, the MCIP protocol extends Mobile IP protocol for providing macro-mobility support between local domains either for single hop MSs or multi-hop MSs. In the MCIP protocol, new location and mobility management approaches are developed for tracking mobile stations, paging, and handoff management. This dissertation also provides a security protocol for integrated Internet and MANET to establish distributed trust relationships amongst mobile infrastructures. This protocol protects communication between two mobile stations against the attacks either from the Internet side or from wireless side. Moreover, a secure macro/micro-mobility protocol (SM3P) have been introduced and evaluated for preventing mobility-related attacks either for single-hop MSs or multi-hop MSs. In the proposed SM3P, mobile IP security has been extended for supporting macro-mobility across local domains through the process of multi-hop registration and authentication. In a local domain, a certificate-based authentication achieves the effective routing and micro-mobility protection from a range of potential security threats

Securing the Internet with digital signatures

The security and reliability of the Internet are essential for many functions of a modern society. Currently, the Internet lacks efficient network level security solutions and is vulnerable to various attacks, especially to distributed denial-of-service attacks. Traditional end-to-end security solutions such as IPSec only protect the communication end-points and are not effective if the underlying network infrastructure is attacked and paralyzed. This thesis describes and evaluates Packet Level Authentication (PLA), which is a novel method to secure the network infrastructure and provide availability with public key digital signatures. PLA allows any node in the network to verify independently the authenticity and integrity of every received packet, without previously established relationships with the sender or intermediate nodes that have handled the packet. As a result, various attacks against the network and its users can be more easily detected and mitigated, before they can cause significant damage or disturbance. PLA is compatible with the existing Internet infrastructure, and can be used with complementary end-to-end security solutions, such as IPSec and HIP. While PLA was originally designed for securing current IP networks, it is also suitable for securing future data-oriented networking approaches. PLA has been designed to scale from lightweight wireless devices to Internet core network, which is a challenge since public key cryptography operations are very resource intensive. Nevertheless, this work shows that digital signature algorithms and their hardware implementations developed for PLA are scalable to fast core network routers. Furthermore, the additional energy consumption of cryptographic operations is significantly lower than the energy cost of wireless transmission, making PLA feasible for lightweight wireless devices. Digital signature algorithms used by PLA also offer small key and signature sizes and therefore PLA's bandwidth overhead is relatively low. Strong security mechanisms offered by PLA can also be utilized for various other tasks. This work investigates how PLA can be utilized for controlling incoming connections, secure user authentication and billing, and for providing a strong accountability without an extensive data retention by network service providers

Proceedings of Seminar on Network Protocols in Operating Systems

The Linux networking stack tends to evolve rapidly, and while there are some excellent documentation written in the past, most of the past documentation gotten (at least partially) outdated over time. The seminar on Network Protocols in Operating Systems was arranged in Aalto University, fall 2012, Department of Communications and Networking to gain a better understanding of the current status of the networking implementation in the Linux kernel. The seminar had 10 participants and each participant was assigned a module from the Linux networking implementation, on which a short paper was to be written. This publications contain the final output of this work. The papers included in the publication are: Kurnikov, Arseny: Linux kernel application interface. Jaakkola, Antti: Implementation of transmission control protocol in Linux. Arianfar, Somaya: TCP’s congestion control implementation in Linux kernel. Budigere, Karthik: Linux implementation study of stream control transmission protocol. Khattak, Fida Ullah: The IPv4 implementation of Linux kernel stack. Boye, Magnus: Netfilter connection tracking and NAT implementation. Korhonen, Jouni: Mobile IPv6 Linux kernel and user space. Soininen, Jonne: Device agnostic network interface. Kalliola, Aapo: Network device drivers in Linux. Varis, Nuutti: Anatomy of a Linux bridge

Improving Energy Efficiency and Security for Pervasive Computing Systems

Pervasive computing systems are comprised of various personal mobile devices connected by the wireless networks. Pervasive computing systems have gained soaring popularity because of the rapid proliferation of the personal mobile devices. The number of personal mobile devices increased steeply over years and will surpass world population by 2016.;However, the fast development of pervasive computing systems is facing two critical issues, energy efficiency and security assurance. Power consumption of personal mobile devices keeps increasing while the battery capacity has been hardly improved over years. at the same time, a lot of private information is stored on and transmitted from personal mobile devices, which are operating in very risky environment. as such, these devices became favorite targets of malicious attacks. Without proper solutions to address these two challenging problems, concerns will keep rising and slow down the advancement of pervasive computing systems.;We select smartphones as the representative devices in our energy study because they are popular in pervasive computing systems and their energy problem concerns users the most in comparison with other devices. We start with the analysis of the power usage pattern of internal system activities, and then identify energy bugs for improving energy efficiency. We also investigate into the external communication methods employed on smartphones, such as cellular networks and wireless LANs, to reduce energy overhead on transmissions.;As to security, we focus on implantable medical devices (IMDs) that are specialized for medical purposes. Malicious attacks on IMDs may lead to serious damages both in the cyber and physical worlds. Unlike smartphones, simply borrowing existing security solutions does not work on IMDs because of their limited resources and high requirement of accessibility. Thus, we introduce an external device to serve as the security proxy for IMDs and ensure that IMDs remain accessible to save patients\u27 lives in certain emergency situations when security credentials are not available

Um sistema colaborativo de cache para stream de vídeos na internet

Monografia (graduação)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2015.Atualmente, uma parcela significativa do tráfego IP é proveniente de stream de vídeos. Um estudo realizado pela Cisco aponta que, em 2018, 79% de todo o tráfego IP irá transportar aplicações de stream de vídeos [13]. Como diversos usuários, dentro de uma rede local, podem possuir interesse nos mesmos vídeos, é gerada uma repetição desnecessária de requisições que saem da rede. O uso de cache mostra-se como uma abordagem para diminuir a quantidade de dados transferidos de forma repetida, diminuir a taxa de uso da largura de banda de saída da rede, aumentar o uso da infra-estrutura de rede interna e diminuir a latência na recuperação dos vídeos. Este trabalho apresenta os conceitos básicos de um sistema de cache e faz uma breve revisão da literatura com base nos trabalhos correlatos. Diferentemente dos modelos referenciados, que propõem uma abordagem centralizada, este trabalho propõe um modelo de cache colaborativo distribuído para stream de vídeos, que tem como objetivo reduzir o consumo da banda de saída da rede. Este modelo utiliza políticas colaborativas que permitem o compartilhamento do cache de cada usuário entre os demais membros da rede. Os resultados apresentados por este trabalho mostram que a implementação do modelo proposto é uma alternativa viável e eficaz para economizar a banda de saída da rede e melhorar a utilização de seus recursos. ____________________________________________________________________________ ABSTRACTCurrently, a significant portion of IP traffic comes from stream videos. A study by Cisco points out that in 2018, 79% of all IP traffic will be video stream applications [13]. As many users, inside a local network, may have interest in the same videos, an unnecessary repetition of outbound requests is made. Caching has proven itself as an approach to reduce the amount of repeated data, decreasing output bandwidth, increasing internal network infrastructure and reducing latency in video recovery. This work presents the basic concepts of a caching system and a brief literature review on the basis of related work. Unlike the referenced models that propose a centralized approach, here a collaborative cache distributed model to stream videos is proposed. This aims to reduce the amount of outgoing network bandwidth. This model uses collaborative policies that allow the cache sharing between all users of the network. The results presented in this work show that the implementation of the proposed model is a viable and effective alternative to save outgoing network bandwidth and improve resources use

A quantitative survey of the power saving potential in IP-Over-WDM backbone networks

The power consumption in Information and Communication Technologies networks is growing year by year; this growth presents challenges from technical, economic, and environmental points of view. This has lead to a great number of research publications on "green" telecommunication networks. In response, a number of survey works have appeared as well. However, with respect to backbone networks, most survey works: 1) do not allow for an easy cross validation of the savings reported in the various works and 2) nor do they provide a clear overview of the individual and combined power saving potentials. Therefore, in this paper, we survey the reported saving potential in IP-over-WDM backbone telecommunication networks across the existing body of research in that area. We do this by mapping more than ten different approaches to a concise analytical model, which allows us to estimate the combined power reduction potential. Our estimates indicate that the power reduction potential of the once-only approaches is 2.3x in a Moderate Effort scenario and 31x in a Best Effort scenario. Factoring in the historic and projected yearly efficiency improvements ("Moore's law") roughly doubles both values on a ten-year horizon. The large difference between the outcome of Moderate Effort and Best Effort scenarios is explained by the disparity and lack of clarity of the reported saving results and by our (partly) subjective assessment of the feasibility of the proposed approaches. The Moderate Effort scenario will not be sufficient to counter the projected traffic growth, although the Best Effort scenario indicates that sufficient potential is likely available. The largest isolated power reduction potential is available in improving the power associated with cooling and power provisioning and applying sleep modes to overdimensioned equipment

Cacheability study for web content delivery

Master'sMASTER OF SCIENC

Reducing the Complexity of Heterogeneous Computing: A Unified Approach for Application Development and Runtime Optimization

Heterogeneous systems with accelerators promise considerable performance improvements at a lower cost than homogeneous CPU-only systems. However, to benefit from this potential, considerable work is required from developers to integrate them efficiently in an application. This work contributes a new framework implemented with an online-learning runtime system that simplifies development and makes applications more portable, efficient and reliable across different systems