Tanja Zseby

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We introduce a charging and accounting (CA) architecture for IP multicast services with QoS guarantees over ATM for QoS-sensitive fair charging. The architecture is based on an extension of the Multicast Integration Server (MIS, [SaCS97]) that efficiently provides IP multicast over ATM, supporting Internet Integrated Services (IS) with receiver(More)
In this paper we propose a layered framework for charging QoS-enhanced IP services with policy based configuration of its layers. As an example architecture we present our implementation-Value Added IP Charging and Accounting Service (VIPCAS). We further concentrate on VIPCAS elements for policies and data exchange. As flexible data structure for exchange(More)
A broad spectrum of network measurement applications demand passive multipoint measurements in which data from multiple observation points has to be correlated. Examples are the passive measurement of one-way delay or the observation of the path that a packet takes through a network. Nevertheless, due to high data rates and the need for fine granular(More)
The Internet has become a complex system with increasing numbers of end-systems, applications, protocols and types of networks. Although we have a good understanding of how data is transferred over the network we cannot observe what happens with our data after sending and before receiving it - how packets traverse through the network and with which QoS(More)
A broad spectrum of network measurement applications demand for multipoint measurements; e.g. one-way delay measurements or packets path tracing. A passive multipoint measurement technique is realized by generating a timestamp and a packet identifier (ID) for each packet traversing an observation point and sending this information to a common collector. The(More)
An IP darkspace is a globally routed IP address space with no active hosts. All traffic destined to darkspace addresses is unsolicited and often originates from network scanning or attacks. A sudden increases of different types of darkspace traffic can serve as indicator of new vulnerabilities, misconfigurations or large scale attacks. In our analysis we(More)
We investigated how Patch Tuesday affects the volume and characteristics of malicious and unwanted traffic as observed by a large IPv4 (/8) darkspace monitor over the first six months of 2012. We did not discover significant changes in overall traffic volume following Patch Tuesday, but we found a significant increase of the number of active hosts sending(More)
Service Level Agreements (SLAs) specify the network Quality of Service (QoS) that providers are expected to deliver. Providers have to verify if the actual quality of the network traffic complies with the SLA. Ideally this should be done without introducing significant additional network load and the operational costs should be small. In this paper we(More)