HTTP-sCAN:Detecting HTTP-Flooding Attack by Modeling Multi-Features of Web Browsing Behavior from Noisy Web-Logs

HTTP-flooding attack disables the victimized web server by sending a large number of HTTP Get requests.Recent research tends to detect HTTP-flooding with the anomaly-based approaches,which detect the HTTP-flooding by modeling the behavior of normal web surfers.However,most of the existing anomaly-based detection approaches usually cannot filter the web-crawling traces from unknown searching bots mixed in normal web browsing logs.These web-crawling traces can bias the base-line profile of anomaly-based schemes in their training phase,and further degrade their detection performance.This paper proposes a novel web-crawling tracestolerated method to build baseline profile,and designs a new anomaly-based HTTP-flooding detection scheme(abbr.HTTP-sCAN).The simulation results show that HTTP-sCAN is immune to the interferences of unknown webcrawling traces,and can detect all HTTPflooding attacks.

Primary User-Awareness-Based Energy-Efficient Duty-Cycle Scheme in Cognitive Radio Networks

Cognitive radio devices can utilize the licensed channels in an opportunistic manner to solve the spectrum scarcity issue occurring in the unlicensed spectrum.However,these cognitive radio devices(secondary users)are greatly affected by the original users(primary users)of licensed channels.Cognitive users have to adjust operation parameters frequently to adapt to the dynamic network environment,which causes extra energy consumption.Energy consumption can be reduced by predicting the future activity of primary users.However,the traditional prediction-based algorithms require large historical data to achieve a satisfying precision accuracy which will consume a lot of time and memory space.Moreover,many of these schemes lack methods to deal with the very busy network environments.In this paper,one semi-supervised learning algorithm,i.e.,tri-training,has been employed to investigate the prediction of primary activity.Based on the prediction results of tri-training,a duty-cycle mechanism and an intermediate node selection approach are proposed to improve the energy efficiency.Simulation results show the effectiveness of the proposed algorithm.

Physical Frame Time-Slot Switching-A New Switching Technique over DWDM

A novel technique called physical frame time-slot switching （PFTS） is discussed and its technical and application aspects are analyzed. The format of the ethernet media access control （MAC） frame is borrowed in defining the physical frame for PFTS and the transmission time for the maximum size of the MAC frame is defined as a physical frame time-slot （PFT）. Consequently, user data can be fed into PFTS and switched in a single layer sub-network in an asynchronous mode.

On Distributed Concurrent Multi-Port Router Test System

This paper presents a framework of the distributed concurrent multi-port-testing test system (CMPT-TS) for IP routers under development at Sichuan Network Communication Key Laboratory. Having analyzed the actuality of concurrent testing for routers, this paper develops a distributed architecture of CMPT-TS and discusses its functional components in detail. Moreover, a new test definition language, CMPT definition language, is also introduced simply.

Microwave photonic bandpass filter based on spectrum-slicing and phase modulator

A tunable microwave photonic bandpass filter with high mainlobe-to-sidelobe ratio (MSR) based on a phase modulator and a dispersive device is proposed. The multi-tap characteristics of the filter are realized by slicing a broadband source using a Mach-Zehnder interferometer (MZI) which results in a high MSR of 25 dB. The tunability of the filter is realized by an optical variable delay line (OVDL) in one arm of the MZI, which changes the wavelength spacing of the sliced broadband source and results in a tunable free spectrum range (FSR) of the filter. The central frequency of the bandpass filter is tunable from 10.7 GHz to 27 GHz by changing the wavelength spacing from 0.145 nm to 0.054 nm.