Seminar Delay-Tolerant Networks

Abstract In this paper, I introduce main concepts of delay-tolerant networks and their architecture. Delay-tolerant networks are designed to operate in environments characterized by very long delay paths and frequent network partitions. In the end, I give results of performance evaluation of the DTN store-and-forward approach compared to traditional Internet data transfer protocols. The paper does not introduce novel approaches created by the author himself but rather should be seen as a summarized review of reference papers

Comparative analysis of attack detection methods in Delay Tolerant Network

Delay Tolerant Network is a new kind of wireless network which includes Radio Frequency (RF) and acoustic (sonar) technologies. DTN developed for an interplanetary network where the speed of light is slow. DTN is derived from deep space communication. DTN is distinguished as long delay and intermittent connectivity. The Delay Tolerant Network is more vulnerable to different kinds of attacks like flooding attack, blackhole and greyhole attacks, due to limited connectivity. There is no end-to-end connectivity between source & destination in DTN. So that it uses a store, carry and forward mechanism to transfer the data from one node to another node. The Delay Tolerant Network was developed to solve technical problems in the end-to-end network. DTN is becoming more and more important because communication networks are ubiquitous today. It provides automotive communication solutions. DTN is a decentralized and self-managed system with unique network attributes; however, attributes such as high mobility nodes, network uplinks and downlinks, and separate routing can cause network vulnerabilities. These vulnerabilities include the host being compromised, which in turn will bring security risks, because the compromised host may destroy the routing protocol in the network. This article analyses the various types of attack detection methods

Comparative analysis of attack detection methods in Delay Tolerant Network

Delay Tolerant Network is a new kind of wireless network which includes Radio Frequency (RF) and acoustic (sonar) technologies. DTN developed for an interplanetary network where the speed of light is slow. DTN is derived from deep space communication. DTN is distinguished as long delay and intermittent connectivity. The Delay Tolerant Network is more vulnerable to different kinds of attacks like flooding attack, blackhole and greyhole attacks, due to limited connectivity. There is no end-to-end connectivity between source & destination in DTN. So that it uses a store, carry and forward mechanism to transfer the data from one node to another node. The Delay Tolerant Network was developed to solve technical problems in the end-to-end network. DTN is becoming more and more important because communication networks are ubiquitous today. It provides automotive communication solutions. DTN is a decentralized and self-managed system with unique network attributes; however, attributes such as high mobility nodes, network uplinks and downlinks, and separate routing can cause network vulnerabilities. These vulnerabilities include the host being compromised, which in turn will bring security risks, because the compromised host may destroy the routing protocol in the network. This article analyses the various types of attack detection methods

On Leveraging Partial Paths in Partially-Connected Networks

Mobile wireless network research focuses on scenarios at the extremes of the network connectivity continuum where the probability of all nodes being connected is either close to unity, assuming connected paths between all nodes (mobile ad hoc networks), or it is close to zero, assuming no multi-hop paths exist at all (delay-tolerant networks). In this paper, we argue that a sizable fraction of networks lies between these extremes and is characterized by the existence of partial paths, i.e. multi-hop path segments that allow forwarding data closer to the destination even when no end-to-end path is available. A fundamental issue in such networks is dealing with disruptions of end-to-end paths. Under a stochastic model, we compare the performance of the established end-to-end retransmission (ignoring partial paths), against a forwarding mechanism that leverages partial paths to forward data closer to the destination even during disruption periods. Perhaps surprisingly, the alternative mechanism is not necessarily superior. However, under a stochastic monotonicity condition between current v.s. future path length, which we demonstrate to hold in typical network models, we manage to prove superiority of the alternative mechanism in stochastic dominance terms. We believe that this study could serve as a foundation to design more efficient data transfer protocols for partially-connected networks, which could potentially help reducing the gap between applications that can be supported over disconnected networks and those requiring full connectivity.Comment: Extended version of paper appearing at IEEE INFOCOM 2009, April 20-25, Rio de Janeiro, Brazi

Content storage and retrieval mechanisms for vehicular delay-tolerant networks

Vehicular delay-tolerant networks (VDTNs) were proposed as a novel disruptive network concept based on the delay tolerant networking (DTN) paradigm. VDTN architecture uses vehicles to relay messages, enabling network connectivity in challenging scenarios. Due to intermittent connectivity, network nodes carry messages in their buffers, relaying them only when a proper contact opportunity occurs. Thus, the storage capacity and message retrieving of intermediate nodes directly affects the network performance. Therefore, efficient and robust caching and forwarding mechanisms are needed. This dissertation proposes a content storage and retrieval (CSR) solution for VDTN networks. This solution consists on storage and retrieval control labels, attached to every data bundle of aggregated network traffic. These labels define cacheable contents, and apply cachecontrol and forwarding restrictions on data bundles. The presented mechanisms gathered several contributions from cache based technologies such as Web cache schemes, ad-hoc and DTN networks. This solution is fully automated, providing a fast, safe, and reliable data transfer and storage management, while improves the applicability and performance of VDTN networks significantly. This work presents the performance evaluation and validation of CSR mechanisms through a VDTN testbed. Furthermore it presents several network performance evaluations and results using the well-known DTN routing protocols, Epidemic and Spray and Wait (including its binary variant). The comparison of the network behavior and performance on both protocols, with and without CSR mechanisms, proves that CSR mechanisms improve significantly the overall network performance