Proceedings of the 3rd MANIAC Challenge, Berlin, Germany, July 27 - 28, 2013
This is the Proceedings of the 3rd MANIAC Challenge, which was held in Berlin, Germany, July 27 - 28, 2013.
cs.NI↗
arXiv subjects
Thomas C. Schmidt
Publications and source records attributed to Thomas C. Schmidt.
Design, Implementation, and Operation of a Mobile Honeypot
Mobile nodes, in particular smartphones are one of the most relevant devices in the current Internet in terms of quantity and economic impact. There is the common believe that those devices are of special interest for attackers due to their limited resources and the serious data they store. On the other hand, the mobile regime is a very lively network environment, which misses the (limited) ground truth we have in commonly connected Internet nodes. In this paper we argue for a simple long-term measurement infrastructure that allows for (1) the analysis of unsolicited traffic to and from mobile devices and (2) fair comparison with wired Internet access. We introduce the design and implementation of a mobile honeypot, which is deployed on standard hardware for more than 1.5 years. Two independent groups developed the same concept for the system. We also present preliminary measurement results.
cs.CR↗
libcppa - Designing an Actor Semantic for C++11
Parallel hardware makes concurrency mandatory for efficient program execution. However, writing concurrent software is both challenging and error-prone. C++11 provides standard facilities for multiprogramming, such as atomic operations with acquire/release semantics and RAII mutex locking, but these primitives remain too low-level. Using them both correctly and efficiently still requires expert knowledge and hand-crafting. The actor model replaces implicit communication by sharing with an explicit message passing mechanism. It applies to concurrency as well as distribution, and a lightweight actor model implementation that schedules all actors in a properly pre-dimensioned thread pool can outperform equivalent thread-based applications. However, the actor model did not enter the domain of native programming languages yet besides vendor-specific island solutions. With the open source library libcppa, we want to combine the ability to build reliable and distributed systems provided by the actor model with the performance and resource-efficiency of C++11.
cs.PL↗
Backscatter from the Data Plane --- Threats to Stability and Security in Information-Centric Networking
Information-centric networking proposals attract much attention in the ongoing search for a future communication paradigm of the Internet. Replacing the host-to-host connectivity by a data-oriented publish/subscribe service eases content distribution and authentication by concept, while eliminating threats from unwanted traffic at an end host as are common in today's Internet. However, current approaches to content routing heavily rely on data-driven protocol events and thereby introduce a strong coupling of the control to the data plane in the underlying routing infrastructure. In this paper, threats to the stability and security of the content distribution system are analyzed in theory and practical experiments. We derive relations between state resources and the performance of routers and demonstrate how this coupling can be misused in practice. We discuss new attack vectors present in its current state of development, as well as possibilities and limitations to mitigate them.
cs.NI↗
Why We Shouldn't Forget Multicast in Name-oriented Publish/Subscribe
Name-oriented networks introduce the vision of an information-centric, secure, globally available publish-subscribe infrastructure. Current approaches concentrate on unicast-based pull mechanisms and thereby fall short in automatically updating content at receivers. In this paper, we argue that an inclusion of multicast will grant additional benefits to the network layer, namely efficient distribution of real-time data, a many-to-many communication model, and simplified rendezvous processes. These aspects are comprehensively reflected by a group-oriented naming concept that integrates the various available group schemes and introduces new use cases. A first draft of this name-oriented multicast access has been implemented in the HAMcast middleware.
cs.NI↗
From a Link Semantic to Semantic Links - Building Context in Educational Hypermedia
Modularization and granulation are key concepts in educational content management, whereas teaching, learning and understanding require a discourse within thematic contexts. Even though hyperlinks and semantically typed references provide the context building blocks of hypermedia systems, elaborate concepts to derive, manage and propagate such relations between content objects are not around at present. Based on Semantic Web standards, this paper makes several contributions to content enrichment. Work starts from harvesting multimedia annotations in class-room recordings, and proceeds to deriving a dense educational semantic net between eLearning Objects decorated with extended LOM relations. Special focus is drawn on the processing of recorded speech and on an Ontological Evaluation Layer that autonomously derives meaningful inter-object relations. Further on, a semantic representation of hyperlinks is developed and elaborated to the concept of semantic link contexts, an approach to manage a coherent rhetoric of linking. These solutions have been implemented in the Hypermedia Learning Objects System (hylOs), our eLearning content management system. hylOs is built upon the more general Media Information Repository (MIR) and the MIR adaptive context linking environment (MIRaCLE), its linking extension. MIR is an open system supporting the standards XML and JNDI. hylOs benefits from configurable information structures, sophisticated access logic and high-level authoring tools like the WYSIWYG XML editor and its Instructional Designer.
cs.IR↗
Broadcasting in Prefix Space: P2P Data Dissemination with Predictable Performance
A broadcast mode may augment peer-to-peer overlay networks with an efficient, scalable data replication function, but may also give rise to a virtual link layer in VPN-type solutions. We introduce a simple broadcasting mechanism that operates in the prefix space of distributed hash tables without signaling. This paper concentrates on the performance analysis of the prefix flooding scheme. Starting from simple models of recursive $k$-ary trees, we analytically derive distributions of hop counts and the replication load. Extensive simulation results are presented further on, based on an implementation within the OverSim framework. Comparisons are drawn to Scribe, taken as a general reference model for group communication according to the shared, rendezvous-point-centered distribution paradigm. The prefix flooding scheme thereby confirmed its widely predictable performance and consistently outperformed Scribe in all metrics. Reverse path selection in overlays is identified as a major cause of performance degradation.
cs.NI↗
On the Correlation of Geographic and Network Proximity at Internet Edges and its Implications for Mobile Unicast and Multicast Routing
Significant effort has been invested recently to accelerate handover operations in a next generation mobile Internet. Corresponding works for developing efficient mobile multicast management are emergent. Both problems simultaneously expose routing complexity between subsequent points of attachment as a characteristic parameter for handover performance in access networks. As continuous mobility handovers necessarily occur between access routers located in geographic vicinity, this paper investigates on the hypothesis that geographically adjacent edge networks attain a reduced network distances as compared to arbitrary Internet nodes. We therefore evaluate and analyze edge distance distributions in various regions for clustered IP ranges on their geographic location such as a city. We use traceroute to collect packet forwarding path and round-trip-time of each intermediate node to scan-wise derive an upper bound of the node distances. Results of different scanning origins are compared to obtain the best estimation of network distance of each pair. Our results are compared with corresponding analysis of CAIDA Skitter data, overall leading to fairly stable, reproducible edge distance distributions. As a first conclusion on expected impact on handover performance measures, our results indicate a general optimum for handover anticipation time in 802.11 networks of 25 ms.
cs.NI↗
A Distributed Multimedia Communication System and its Applications to E-Learning
In this paper we report on a multimedia communication system including a VCoIP (Video Conferencing over IP) software with a distributed architecture and its applications for teaching scenarios. It is a simple, ready-to-use scheme for distributed presenting, recording and streaming multimedia content. We also introduce and investigate concepts and experiments to IPv6 user and session mobility, with the special focus on real-time video group communication.
cs.MM↗
Performance Analysis of Multicast Mobility in a Hierarchical Mobile IP Proxy Environment
Mobility support in IPv6 networks is ready for release as an RFC, stimulating major discussions on improvements to meet real-time communication requirements. Sprawling hot spots of IP-only wireless networks at the same time await voice and videoconferencing as standard mobile Internet services, thereby adding the request for multicast support to real-time mobility. This paper briefly introduces current approaches for seamless multicast extensions to Mobile IPv6. Key issues of multicast mobility are discussed. Both analytically and in simulations comparisons are drawn between handover performance characteristics, dedicating special focus on the M-HMIPv6 approach.
cs.NI↗
Educational Content Management - A Cellular Approach
In recent times online educational applications more and more are requested to provide self-consistent learning offers for students at the university level. Consequently they need to cope with the wide range of complexity and interrelations university course teaching brings along. An urgent need to overcome simplistically linked HTMLc ontent pages becomes apparent. In the present paper we discuss a schematic concept of educational content construction from information cells and introduce its implementation on the storage and runtime layer. Starting from cells content is annotated according to didactic needs, structured for dynamic arrangement, dynamically decorated with hyperlinks and, as all works are based on XML, open to any presentation layer. Data can be variably accessed through URIs built on semantic path-names and edited via an adaptive authoring toolbox. Our content management approach is based on the more general Multimedia Information Repository MIR. and allows for personalisation, as well. MIR is an open system supporting the standards XML, Corba and JNDI.
cs.CY↗
Semantic Linking - a Context-Based Approach to Interactivity in Hypermedia
The semantic Web initiates new, high level access schemes to online content and applications. One area of superior need for a redefined content exploration is given by on-line educational applications and their concepts of interactivity in the framework of open hypermedia systems. In the present paper we discuss aspects and opportunities of gaining interactivity schemes from semantic notions of components. A transition from standard educational annotation to semantic statements of hyperlinks is discussed. Further on we introduce the concept of semantic link contexts as an approach to manage a coherent rhetoric of linking. A practical implementation is introduced, as well. Our semantic hyperlink implementation is based on the more general Multimedia Information Repository MIR, an open hypermedia system supporting the standards XML, Corba and JNDI.
cs.IR↗
Roaming Real-Time Applications - Mobility Services in IPv6 Networks
Emerging mobility standards within the next generation Internet Protocol, IPv6, promise to continuously operate devices roaming between IP networks. Associated with the paradigm of ubiquitous computing and communication, network technology is on the spot to deliver voice and videoconferencing as a standard internet solution. However, current roaming procedures are too slow, to remain seamless for real-time applications. Multicast mobility still waits for a convincing design. This paper investigates the temporal behaviour of mobile IPv6 with dedicated focus on topological impacts. Extending the hierarchical mobile IPv6 approach we suggest protocol improvements for a continuous handover, which may serve bidirectional multicast communication, as well. Along this line a multicast mobility concept is introduced as a service for clients and sources, as they are of dedicated importance in multipoint conferencing applications. The mechanisms introduced do not rely on assumptions of any specific multicast routing protocol in use.
cs.NI↗
Hypermedia Learning Objects System - On the Way to a Semantic Educational Web
While eLearning systems become more and more popular in daily education, available applications lack opportunities to structure, annotate and manage their contents in a high-level fashion. General efforts to improve these deficits are taken by initiatives to define rich meta data sets and a semanticWeb layer. In the present paper we introduce Hylos, an online learning system. Hylos is based on a cellular eLearning Object (ELO) information model encapsulating meta data conforming to the LOM standard. Content management is provisioned on this semantic meta data level and allows for variable, dynamically adaptable access structures. Context aware multifunctional links permit a systematic navigation depending on the learners and didactic needs, thereby exploring the capabilities of the semantic web. Hylos is built upon the more general Multimedia Information Repository (MIR) and the MIR adaptive context linking environment (MIRaCLE), its linking extension. MIR is an open system supporting the standards XML, Corba and JNDI. Hylos benefits from manageable information structures, sophisticated access logic and high-level authoring tools like the ELO editor responsible for the semi-manual creation of meta data and WYSIWYG like content editing.
cs.IR↗