Non-Trivial Off-Path Network Measurements without Shared Side-Channel Resource Exhaustion

Most traditional network measurement scans and attacks are carried out through the use of direct, on-path network packet transmission. This requires that a machine be on-path (i.e, involved in the packet transmission process) and as a result have direct access to the data packets being transmitted. This limits network scans and attacks to situations where access can be gained to an on-path machine. If, for example, a researcher wanted to measure the round trip time between two machines they did not have access to, traditional scans would be of little help as they require access to an on-path machine to function. Instead the researcher would need to use an off-path measurement scan. Prior work using network side-channels to perform off-path measurements or attacks relied on techniques that either exhausted the shared, finite resource being used as a side-channel or only measured basic features such as connectivity. The work presented in this dissertation takes a different approach to using network side-channels. I describe research that carries out network side-channel measurements that are more complex than connectivity, such as packet round-trip-time or detecting active TCP connections, and do not require a shared, finite resource be fully exhausted to cause information to leak via a side-channel. My work is able to accomplish this by understanding the ways in which internal network stack state changes cause observable behavior changes from the machine. The goal of this dissertation is to show that: Information side-channels can be modulated to take advantage of dependent, network state behavior to enable non-trivial, off-path measurements without fully exhausting the shared, finite resources they use

A New Analysis of the DS-CDMA Cellular Uplink Under Spatial Constraints

A new analysis is presented for the direct-sequence code-division multiple access (DS-CDMA) cellular uplink. For a given network topology, closed-form expressions are found for the outage probability and rate of each uplink in the presence of path-dependent Nakagami fading and log-normal shadowing. The topology may be arbitrary or modeled by a random spatial distribution for a fixed number of base stations and mobiles placed over a finite area with the separations among them constrained to exceed a minimum distance. The analysis is more detailed and accurate than existing ones and facilitates the resolution of network design issues, including the influence of the minimum base-station separation, the role of the spreading factor, and the impact of various power-control and rate-control policies. It is shown that once power control is established, the rate can be allocated according to a fixed-rate or variable-rate policy with the objective of either meeting an outage constraint or maximizing throughput. An advantage of the variable-rate policy is that it allows an outage constraint to be enforced on every uplink, whereas the fixed-rate policy can only meet an average outage constraint.Comment: 6 pages, 6 figures, to appear at International Conference on Communications (ICC) 201

Opportunistic Source Coding for Data Gathering in Wireless Sensor Networks

We propose a jointly opportunistic source coding and opportunistic routing (OSCOR) protocol for correlated data gathering in wireless sensor networks. OSCOR improves data gathering efficiency by exploiting opportunistic data compression and cooperative diversity associated with wireless broadcast advantage. The design of OSCOR involves several challenging issues across different network protocol layers. At the MAC layer, sensor nodes need to coordinate wireless transmission and packet forwarding to exploit multiuser diversity in packet reception. At the network layer, in order to achieve high diversity and compression gains, routing must be based on a metric that is dependent on not only link-quality but also compression opportunities. At the application layer, sensor nodes need a distributed source coding algorithm that has low coordination overhead and does not require the source distributions to be known. OSCOR provides practical solutions to these challenges incorporating a slightly modified 802.11 MAC, a distributed source coding scheme based on network coding and Lempel-Ziv coding, and a node compression ratio dependent metric combined with a modified Dijkstra's algorithm for path selection. We evaluate the performance of OSCOR through simulations, and show that OSCOR can potentially reduce power consumption by over 30% compared with an existing greedy scheme, routing driven compression, in a 4 x 4 grid network

PIPELINED CIRCUIT SWITCHING ROUTINE IN A ENERGETIC LANE COMPLEX SYSTEM

An engaged path setup plan from the suggested design to aid a runtime path arrangement once the permutation is altered. In every path setup, which starts from a port to locate a path resulting in its corresponding output, is dependent on an engaged probing mechanism. The novel on-nick network in plastic proven design to aid guaranteed traffic permutation in multiprocessor SOC applications. A pipelined circuit-switching Used in the suggested network with FIFO approach coupled with a multistage network topology in dynamic path-setup plan. The runtime path arrangement enabled by dynamic path-setup plan for arbitrary traffic permutations combined with the Error Correction Block (ECB). The Exhausted lucrative backtracking (EPB) use to route the probe within the network work. A way arrangement with full permutation includes 16 path setups, whereas a way arrangement with partial permutation may contain a subset of 16 path setups. A CMOS test-nick with .13m validates the practicality and efficiency from the suggested design. The proven experimental increase the risk for suggested on-nick network achieves decrease in plastic overhead when compared with other design approaches. The circuit-switching approach provides the permuted data and it is compact overhead enables the advantage of stacking multiple systems in system on nick

Routing of Electric Vehicles in a Stochastic Network with Non-recurrent Incidents

An approach for mapping an electric vehicle (EV) driver’s travel time constraints and risk-taking behavior to real-time routing in a probabilistic, time-dependent (or stochastic) network is proposed in this paper. The proposed approach is based on a heuristic algorithm that finds the shortest path according to the driver’s preferences. Accounting for en-route delays and alternate routes, the EV routing problem in stochastic networks is shown to exhibit other than the First-In-First-Out (FIFO) property; i.e., the traveling time for those who depart earlier may not reach sooner of those who depart later or wait en-route in the charging stations. The proposed approach provides EV drivers the option to manage their trip and reach the destination on time, while by taking advantage of the non-FIFO characteristics of the traffic network, charge their cars en-route. The proposed routing algorithm is tested on a given stochastic transportation network. The best routes based on the driver’s preferences are identified while accounting for the best-planned delays at the charging stations or en-route

Theorising path dependence : how does history come to matter in organisations, and what can we do about it?

This paper examines the concept of path dependence in organisational theory, attempting to utilise insights from a number of academic disciplines to improve our understanding of it. It examines the claims of the resource-based view of business, perhaps the organisational approach most commonly linked with path dependence, and reassesses them in the light of the framework presented here. It concludes by considering the role of history in organisations, the mechanisms through which it manifests itself in the present, and what we can do to break free from path dependence

Joint dimensioning of server and network infrastructure for resilient optical grids/clouds

We address the dimensioning of infrastructure, comprising both network and server resources, for large-scale decentralized distributed systems such as grids or clouds. We design the resulting grid/cloud to be resilient against network link or server failures. To this end, we exploit relocation: Under failure conditions, a grid job or cloud virtual machine may be served at an alternate destination (i.e., different from the one under failure-free conditions). We thus consider grid/cloud requests to have a known origin, but assume a degree of freedom as to where they end up being served, which is the case for grid applications of the bag-of-tasks (BoT) type or hosted virtual machines in the cloud case. We present a generic methodology based on integer linear programming (ILP) that: 1) chooses a given number of sites in a given network topology where to install server infrastructure; and 2) determines the amount of both network and server capacity to cater for both the failure-free scenario and failures of links or nodes. For the latter, we consider either failure-independent (FID) or failure-dependent (FD) recovery. Case studies on European-scale networks show that relocation allows considerable reduction of the total amount of network and server resources, especially in sparse topologies and for higher numbers of server sites. Adopting a failure-dependent backup routing strategy does lead to lower resource dimensions, but only when we adopt relocation (especially for a high number of server sites): Without exploiting relocation, potential savings of FD versus FID are not meaningful

Resilient network dimensioning for optical grid/clouds using relocation

In this paper we address the problem of dimensioning infrastructure, comprising both network and server resources, for large-scale decentralized distributed systems such as grids or clouds. We will provide an overview of our work in this area, and in particular focus on how to design the resulting grid/cloud to be resilient against network link and/or server site failures. To this end, we will exploit relocation: under failure conditions, a request may be sent to an alternate destination than the one under failure-free conditions. We will provide a comprehensive overview of related work in this area, and focus in some detail on our own most recent work. The latter comprises a case study where traffic has a known origin, but we assume a degree of freedom as to where its end up being processed, which is typically the case for e. g., grid applications of the bag-of-tasks (BoT) type or for providing cloud services. In particular, we will provide in this paper a new integer linear programming (ILP) formulation to solve the resilient grid/cloud dimensioning problem using failure-dependent backup routes. Our algorithm will simultaneously decide on server and network capacity. We find that in the anycast routing problem we address, the benefit of using failure-dependent (FD) rerouting is limited compared to failure-independent (FID) backup routing. We confirm our earlier findings in terms of network capacity savings achieved by relocation compared to not exploiting relocation (order of 6-10% in the current case studies)