KIRA: Distributed Scalable ID-based Routing with Fast Forwarding

Emerging network infrastructures are increasingly softwarized, virtualized and, thus, flexible. They may even be viewed as a large, dynamic, and distributed elastic resource pool of network devices that can be flexibly configured and employed according to the needs of network services. Full control of such a resource pool requires resilient control plane connectivity. In this paper, we present KIRA, a two-tier routing architecture that provides self-organized, zero-touch, and extremely robust control plane connectivity. KIRA consists of the distributed, highly scalable, ID-based routing protocol R²/Kad that can run on top of any link layer. It is complemented by a forwarding tier with PathID-based fast forwarding for (control) data packets. KIRA shows excellent performance even in very large networks (evaluated with up to 200000 nodes). R²/Kad allows for flexible memory/stretch tradeoff per node and finds shortest paths to certain destinations in most cases. R²/Kad converges loop-free and fast, even in very large networks with drastic failure scenarios

Managing Trust in a Peer-2-Peer Information System

Managing trust is a problem of particular importance in peer-to-peer environments as one encounters frequently unknown agents. Existing methods for trust management based on reputation do however not scale as they rely on some form of central database or global knowledge to be maintained at each agent. In this paper we illustrate that the problem needs to be addressed at both the data management and the semantic, i.e. trust management, level and we devise a method of how trust assessments can be performed by using at both levels scalable peer-to-peer mechanisms. We expect that such methods are an important factor if fully decentralized peer-to-peer systems should become the platform for more serious applications than simple file exchange

Maximum Likelihood Estimation of Peers' Performance in P2P Networks

The problem of encouraging trustworthy behavior in P2P online communities by managing peers' reputations has drawn a lot of attention recently. However, most of the proposed solutions exhibit the following two problems: huge implementation overhead and unclear trust related model semantics. In this paper we show that a simple probabilistic technique, maximum likelihood estimation namely, can reduce these two problems substantially when employed as the feedback aggregation strategy. Thus, no complex exploration of the feedback is necessary. Instead, simple, intuitive and e#cient probabilistic estimation methods su#ce

Separating Business Process from User Interaction Utilizing Process-Aware XSLT Style-Sheets

In the web context, it is difficult to disentangle presentation from process logic, and sometimes even data is not separate from the presentation. Consequently, it becomes crucial to define an abstract model for business processes, and their mapping into an active user interface presentation, using the principle of separation of concern between the process logic, data and its presentation aspects. We endeavor to extend declarative (rule based) XSLT to accommodate the separation of process information from the data structure and presentation, and thus propose to design process aware stylesheets, in a minimally invasive manner. The isolation of the three otherwise entangled aspects of web-processes makes it easy to develop and maintain webapplications in a more independent manner, where each individual developer can focus on his/her primary responsibility, like describing the process, maintaining a database, or creating user interface (web-pages) without being levied any substantial effort to learn new technology. Full document</a

Trust-Aware Cooperation

In mobile teamwork environments two basic problems exist: how to discover someone based on a profile (skills, reputations) and how to assess that person&#8217;s &#8220;credibility&#8221; (trust). A lot of work has been done on the issues of collecting and spreading reputations and subsequent computation of trust. The application of such data for decision making, however, is still missing. In this paper we present a solution for scheduling exchanges among participants of an online community which take into account their trustworthiness. Full document</a

Hybrid DHT Design for Mobile Environments

In this paper we present a hybrid design concept for Distributed Hash Tables (DHTs), in order to increase the performance of DHTs in scenarios with mobile participants. By defining two classes of nodes (static and temporary) and assigning critical overlay networking tasks to reliable static nodes, our concept; allows the disburdening of resource-constrained temporary nodes such as PDAs or mobile phones. Further we present an implementation of our system design, based on the Chord protocol, in the Network Simulator 2 (NS-2) and in the overlay simulator L7Sim and show simulation results that prove the significant advantages of our extension in comparison to conventional DHTs

Bandwidth-efficient delay- and loss-tolerant overlay routing

Motivation. Peer-to-peer (P2P) systems are mostly deployed in heterogeneous environments with resource availability varying not only across the nodes but also over time. If any of the shared computational, storage or network resources are exhausted, failures and delays occur. The commonly used crash-stop failure model assumes that once a node stops sending messages it never again resumes. Such failures are trivially detected and appropriate algorithms are run that maintain the connectivity and routing efficiency of the P2P overlay under continuous arrivals and departures of the peers (i.e. churn) [6], [4]. The failure detection mechanisms in the crashstop model are typically tuned to minimize th