18,297 research outputs found
Satellite B-ISDN traffic analysis
The impact of asynchronous transfer mode (ATM) traffic on the advanced satellite broadband integrated services digital network (B-ISDN) with onboard processing is reported. Simulation models were built to analyze the cell transfer performance through the statistical multiplexer at the earth station and the fast packet switch at the satellite. The effectiveness of ground ATM cell preprocessing was established, as well as the performance of several schemes for improving the down-link beam utilization when the space segment employs a fast packet switch
Non-blind watermarking of network flows
Linking network flows is an important problem in intrusion detection as well
as anonymity. Passive traffic analysis can link flows but requires long periods
of observation to reduce errors. Active traffic analysis, also known as flow
watermarking, allows for better precision and is more scalable. Previous flow
watermarks introduce significant delays to the traffic flow as a side effect of
using a blind detection scheme; this enables attacks that detect and remove the
watermark, while at the same time slowing down legitimate traffic. We propose
the first non-blind approach for flow watermarking, called RAINBOW, that
improves watermark invisibility by inserting delays hundreds of times smaller
than previous blind watermarks, hence reduces the watermark interference on
network flows. We derive and analyze the optimum detectors for RAINBOW as well
as the passive traffic analysis under different traffic models by using
hypothesis testing. Comparing the detection performance of RAINBOW and the
passive approach we observe that both RAINBOW and passive traffic analysis
perform similarly good in the case of uncorrelated traffic, however, the
RAINBOW detector drastically outperforms the optimum passive detector in the
case of correlated network flows. This justifies the use of non-blind
watermarks over passive traffic analysis even though both approaches have
similar scalability constraints. We confirm our analysis by simulating the
detectors and testing them against large traces of real network flows
TARANET: Traffic-Analysis Resistant Anonymity at the NETwork layer
Modern low-latency anonymity systems, no matter whether constructed as an
overlay or implemented at the network layer, offer limited security guarantees
against traffic analysis. On the other hand, high-latency anonymity systems
offer strong security guarantees at the cost of computational overhead and long
delays, which are excessive for interactive applications. We propose TARANET,
an anonymity system that implements protection against traffic analysis at the
network layer, and limits the incurred latency and overhead. In TARANET's setup
phase, traffic analysis is thwarted by mixing. In the data transmission phase,
end hosts and ASes coordinate to shape traffic into constant-rate transmission
using packet splitting. Our prototype implementation shows that TARANET can
forward anonymous traffic at over 50~Gbps using commodity hardware
Heavy-traffic analysis of k-limited polling systems
In this paper we study a two-queue polling model with zero switch-over times
and -limited service (serve at most customers during one visit period
to queue , ) in each queue. The arrival processes at the two queues
are Poisson, and the service times are exponentially distributed. By increasing
the arrival intensities until one of the queues becomes critically loaded, we
derive exact heavy-traffic limits for the joint queue-length distribution using
a singular-perturbation technique. It turns out that the number of customers in
the stable queue has the same distribution as the number of customers in a
vacation system with Erlang- distributed vacations. The queue-length
distribution of the critically loaded queue, after applying an appropriate
scaling, is exponentially distributed. Finally, we show that the two
queue-length processes are independent in heavy traffic
Duplicate detection methodology for IP network traffic analysis
Network traffic monitoring systems have to deal with a challenging problem:
the traffic capturing process almost invariably produces duplicate packets. In
spite of this, and in contrast with other fields, there is no scientific
literature addressing it. This paper establishes the theoretical background
concerning data duplication in network traffic analysis: generating mechanisms,
types of duplicates and their characteristics are described. On this basis, a
duplicate detection and removal methodology is proposed. Moreover, an
analytical and experimental study is presented, whose results provide a
dimensioning rule for this methodology.Comment: 7 pages, 8 figures. For the GitHub project, see
https://github.com/Enchufa2/nantool
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