1,721,229 research outputs found
Stochastic traffic features and queueing working conditions: A simulation study
No full textThe paper presents an extended simulation study aimed to the evaluation of the impact on queueing performance of different statistical features of actual traffic data. In particular the relevance of marginal distribution (pdf of the arrival rate) and memory properties (LRD - SRD) is considered highlighting the impact of these features in different queueing scenarios, varying queue length and loading conditions.
The study is carried out by means of discrete event simulation driven by actual traces (collected during measurement sessions) and synthetic sequences generated according to different models. The choice of the generation procedures is motivated by model adequacy in capturing the considered statistical features of actual traffic. The analysis emphasises the need of a proper methodology (which takes into account working conditions) in model selection for realistic queueing performance evaluation
CAC algorithm for per-VC queueing systems loaded by fractal traffic
No full textATM technology is expected to support a broad variety of services and applications, satisfying a wide range of user quality needs and network performance objectives. In this scenario a per-Virtual Connection (per-VC) queueing is needed to guarantee different Quality of Service (QoS) requirements and to provide adequate congestion avoidance techniques (such as Early Packet Discard) to single traffic flows. In the paper we present a Call Admission Control (CAC) scheme with per-VC management of network resources. Starting from the widely accepted long memory properties of broadband traffics, fractional Brownian motion (fBm) is used as a parsimonious traffic model. The proposed CAC scheme employs the knowledge of the exact asymptotic queue length distribution to efficiently allocate network resources (buffer and output link capacity) to the contending sources. We analyze the multiplexing gain considering an appropriate distribution of the bandwidth among different sources, highlighting its advantages over the Rate Envelope Multiplexing scheme, suggested by ITU-T
Estimation of token bucket parameters of VoIP traffic
No full textIn the paper, we present a procedure to evaluate the parameters of the LEAP (Linear Bounded A-rival Processes) traffic characterisation when a stochastic model of considered traffic flow is available. The procedure, based on an equivalent queuing system, has been applied to a VoIP (Voice over IF) scenario in a DiffServ, (Differentiated Services) network architecture. In particular, we consider the characterisation of a traffic flow composed by the aggregation of telephone sources with VAD (Voice Activity Detection), where each one has been modelled by a fluidic On-Off process with exponentially distributed sojourn times in each state. For testing the goodness of our approach we have carried out discrete events simulations, which have highlighted the accuracy of the proposed procedure in the considered scenario
Estimation of token bucket parameters for aggregated VoIP sources
No full textThe paper presents an analytical study aimed to establish a dimensioning procedure for the token bucket algorithm, used as a meter in a Differentiated Services network architecture, when a stochastic model for the multiplexed traffic is available. In the work, we propose an equivalent queueing system method to 'on line' estimate the linear bounded arrival processes (LBAP) parameters when a non-zero probability of non-conforming packets is accepted. Then, we validate our approach considering an aggregation of fluidic On-Off processes with exponentially distributed sojourn time in each state, used to model telephone sources with voice activity detection (VAD). To test the goodness of our analytical results, we employ discrete event simulations, which have highlighted the accuracy of the proposed dimensioning procedure in a voice over IP (VoIP) scenario. Moreover, we investigate the multiplexing gain and the effect of different parameters on the LBAP characterization of the VoIP traffic, taking into account a non-zero probability of non-conforming packets. Copyright (C) 2002 John Wiley Sons, Ltd
A Multiplexing Scheme using a Prediction Based Scheduling Strategy for Self-Similar Traffic
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First International workshop onAdvanced EXPerimental activities on WIRELESS networks and systems (EXPONWIRELESS 2006): Message from the workshop organizers
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