Wireless sensor networks for intrusion detection: packet traffic modeling

Performance evaluation of wireless sensor network (WSN) protocols requires realistic data traffic models since most of the WSNs are application specific. In this letter, a sensor network packet traffic model is derived and analyzed for intrusion detection applications. Presented analytical work is also validated using simulations.     

数据分组网中自相似业务模型的研究进展

本文介绍了数据分组网络中业务模型的研究进展。数据分组网络中，传统的泊松或马尔科夫模型在描述网络业务的精确性方面有很大的不足，近年来发展的自相似（单元形）业务模型效果较好。最近，研究人员在实测网络业务数据的基础上提出的多分形模型，不但能很好地模拟网络业务的长相关性，还能表现其在小的时间尺度下的特性。本文简单介绍了单分形业务模型，然后对多分形业务模型进行了重点的阐述，对业务模型的研究进展做出了分析。     

Accuracy of traffic modeling in fast packet switching

Arrivals of calls, bursts, and packets to a fast packet switching system are governed by different time scales. This feature is used to break down the system performance analysis into layers. The impact of each layer on packet delay and blocking is investigated in isolation by assuming the global equilibrium in the next higher layer and deterministic flow of entities in all lower layers. The one-layer analytical model is developed and used to determine lower and upper estimates of a mean delay and blocking. Numerical results are compared with delays obtained from the multilayer simulation. Results of the analysis indicate that the channel utilization must be kept below a threshold value to avoid overload periods in the burst and call layers. Flow control techniques which can be used for that purpose are briefly discussed     

Moment analysis for traffic associated with Markovian queueingsystems

A study is made of various traffic processes associated with Markovian queuing systems, and the moments of the traffic processes are analyzed. The purpose of the study is to develop a means of computing the moments efficiently so as to extend the conventional method of representing the traffic processes to a larger class of queuing systems. As an outcome of the analysis, the recurrence formulae for computing the moments including cross-covariances between multiple traffic processes are derived and expressed in terms of the infinitesimal generator, steady-state probability vector of the Markovian queuing system and a matrix describing traffic rate. The main feature of the analysis is in the utilization of the special block-partitioned structure of the matrices involved. The results are of wide application for the study of various telecommunication networks. Two examples of applications for the Markovian queuing model with batch arrivals and a multislot integrated services system are presented     

A new approach for medium-access control for data traffic and itsadaptation to the GSM general packet radio services

The inhibit sense multiple access with polling (ISMA/P) is a packet-based medium-access control scheme for statistical multiplexing of data users over a single slotted channel of a time-division multiple-access (TDMA) cellular system. In ISMA/P, the central base station (BS) asserts control over the users by polling data in smaller blocks. This enables ISMA/P to attain a near ideal, steady, and high throughput and low-mean delay performance, which is not usually achievable by contention-reservation-based MAC schemes. In this paper, we describe the ISMA/P algorithm and provide a detailed simulation study of it over a global system for mobile communications (GSM)-like slotted channel for a traffic model adopted from European Railways applications. This study shows that ISMA/P can achieve a steady throughput of 90% over a large range of load. A number of practical advantages of ISMA/P, such as elimination of channel hogging, incorrect channel sensing, battery saving, etc., are also elaborated     

Using a packet switch for circuit-switched traffic: a queueingsystem with periodic input traffic

Consideration is given to the effects of time-multiplexed stream traffic on the performance of a store-and-forward packet switch. Substantially reducing the amount of buffering in the switch results in only a small probability that an existing circuit will be disrupted during the length of its connection. For example, with a circuit-switched frame of length 1000 and 100% loading, reducing the buffer size from 999 packets to 83 results in only a 10^-6 circuit-disruption probability     

Calculation of packet jitter for non-poisson traffic

The packet delay variation, commonly called delay jitter, is an important quality of service parameter in IP networks especially for real-time applications. In this paper, we propose the exact and approximate models to compute the jitter for some non-Poisson FCFS queues with a single flow that are important for recent IP network. We show that the approximate models are sufficiently accurate for design purposes. We also show that these models can be computed sufficiently fast to be usable within some iterative procedure, e.g., for dimensioning a playback buffer or for flow assignment in a network.     

A medium-access control protocol for a cellular packet CDMAcarrying multirate traffic

We propose and evaluate a medium-access control (MAC) protocol for synchronous cellular packet direct-sequence code-division multiple-access (DS/CDMA). The protocol is designed for handling a variety of multimedia traffic types in an integrated wireless-access network (IWAN). For instance, the protocol is suited for carrying multiple traffic types of different priorities. An analytical model for the equilibrium state has been developed for the proposed protocol. A comparative evaluation of the protocol is done for three different radio frequency bandwidths currently under consideration for personal communication services (PCS), i.e., 1.25 MHz, 5 MHz, and 10 MHz. Our results demonstrate that the proposed protocol is both robust and flexible for the intended IWAN applications. It offers a significant multiplexing gain as the bandwidth increases     

A flow-based approach to modeling ADSL traffic on an IP backbone link

Measurements from an Internet backbone link carryingtcp traffic towards differentadsl areas are analyzed in this paper. For traffic analysis, we adopt a flow-based approach and the popular mice/elephants dichotomy. The originality of the experimental data reported in this paper, when compared with previous measurements from very high speed backbone links, is that commercial traffic comprises a significant part due to peer-to-peer applications. This kind of traffic exhibits some remarkable properties in terms of mice, elephants and bit rates, which are thoroughly described in this paper. Global traffic is actually decomposed into several flow components on the basis of the mice/elephants dichotomy. Mice due p2p protocols and mice due to classical Internet applications such ashttp, ftp, etc. are analyzed separately. It turns out that by adopting a suitable level of aggregation, global traffic can be described by means of usual tele-traffic models based on M/G/∞ queues with Weibullian service times. The blobal bit rate can then be approximated by the superposition of Gaussian processes perturbed by a white noise.     

Buffer sizing for synchronous self-routeing broadband packet switches with bursty traffic

Previous studies on the performance of synchronous self-routeing packet switches have assumed that the input traffic is random, i.e. there is no correlation between adjacent packet arrivals. This assumption is generally not valid in the data communication environment (e.g. host-to-host communication) where a file transfer usually generates a string of correlated packets. The consequence is that the random traffic assumption greatly underestimates the buffer requirement of the switch. In this paper, we model each input traffic stream as a binary source as a first step to understand the performance of a packet switch in a bursty traffic environment. We found that, given a fixed traffic load (or switch utilization), the required buffer size increases linearly as the burstiness index (the average burst length) of the traffic increases. In addition, the required buffer size is more sensitive to the burstiness of the traffic, when the average traffic load is higher and when the packet loss requirement is more stringent. Initial applications of broadband packet switches are likely to be the interconnections of LANs and hosts. The results of the study indicate that the high burstiness in certain broadband traffic significantly reduces the allowable switch utilization, given a fixed amount of buffers. To increase the switch utilization, an appropriate congestion control mechanism needs to be implemented.     

Providing traffic tolerance in optical packet switching networks: a reinforcement learning approach

The servitization of network resources leads to new challenges for optical networks. For instance, to provide on-demand lightpaths as a service while keeping the probability of packet loss (PPL) low, issues such as lightpath setting up, resource reservation and load balancing must be addressed. We present a self-adaptive framework to process lightpath requests on packet switching optical networks that considers and handles the aforementioned issues. The framework is composed of a dimensioning phase that adds up new resources to an initial topology and a learning phase based on reinforcement learning that provides self-adaptation to tolerate traffic changes. The framework is tested on three realistic mesh topologies achieving a PPL between \(1 \times 10^{-1}\) and \(1 \times 10^{-6}\) for different traffic loads. Compared to fixed multi-path routing strategies, our framework reduces PPL between \(19\%\) and up to \(80\%\). Furthermore, no packet loss can also be achieved for traffic loads equal to or lower than 0.4.     

An efficient modeling and dimensioning approach for integrated streaming and elastic traffic

Recent studies show that both data traffic and real-time traffic grow very fast in wired and wireless networks. To provide better performance guarantee, these applications need efficient network modeling and planning. In this paper, the problem where the total bandwidth of a link is shared by streaming traffic (real time traffic such as voice or video etc.) and elastic traffic (such as data) is studied. Integrating streaming traffic and elastic traffic presents a unique dimensioning problem. This paper considers dimensioning a link to satisfy both quality of service (QoS) requirements for streaming traffic, such as loss probability, and elastic traffic, such as mean waiting (delay) time. The Erlang loss model is applied to streaming traffic and a bursty traffic model is applied to the elastic traffic. Efficient dimensioning algorithms based on classical Markovian models and time-scale decomposition are then proposed. Numerical results show that the proposed methods have good accuracy.     

一种基于负载选择的光分组交换缓存结构

提出了一种基于业务负载选择的光分组交换(OPS)网络的光缓存结构,根据业务负载大小灵活选择缓存方式。输出缓存光纤延迟线(FDL)采用分段式共享机制配置,输出/反馈共享缓存模块采用简并式配置,以提高有限数目FDL的利用率。分析和仿真表明,这种可选择的缓存结构可以有效降低丢包率和OPS节点需求的FDL数目。     

A new approach for VoIP traffic characterization

The letter proposes a new frame generation model for those audio codecs which handle SID frames and deduces an analytical expression for the mean bit rate at the input of the IP network as a function of the number of frames per packet. The new model is experimentally validated for the G.729B, G.723.1, and GSM AMR codecs. Results show that the error of the estimation of the mean bit rate can be reduced significantly compared to the traditional on-off model.     

Distributed probabilistic medium access with multipacket reception and Markovian traffic

Enabling multipacket reception (MPR) at the physical layer is a promising way to achieve higher bandwidth efficiency while reducing the complexity of the medium access control layer in distributed wireless networks. We study distributed probabilistic access where transmitting nodes access the shared wireless medium with a probability based on the node’s information about the aggregate traffic carried by the network. We model bursty traffic by rate-controlled two-state Markov sources and introduce a parameter that describes the “burstiness” level of the offered traffic. A throughput-optimal medium access strategy utilizing limited feedback is then described and its performance is examined for traffic with different levels of burstiness. It is shown that the bursty nature of the traffic in data networks allows for improvement of the bandwidth efficiency. Bounds on the system throughput are proposed and the queuing delay is analyzed.     

Transporting voice traffic over packet networks

POTS networks are being rapidly superceded by newer, packet-based ones, which allows a greater facility for voice traffic. This article explores the practical issues involved in deploying voice networks over ATM, frame relay and IP. © 1998 by John Wiley & Sons, Ltd.     

A fuzzy control approach for adaptive traffic routing

The application of fuzzy control to adaptive traffic routing in telephone networks is investigated. The authors use, on one hand, the properties of fuzzy control techniques and adaptive routing, on the other hand, to derive a routing system that is robust and efficient. They analyze the impact of various availability indicators on performance, which indicates that the choice of a suitable indicator must be made to characterize circuit group availability. When used in the fuzzy control framework the indicator used appears clearly to improve the performance of the routing algorithm as compared to existing routing systems. On the other hand, the use of this indicator in a classical way appears to be of poor utility. The study compares the performance of methods usually applied to adaptive traffic routing and the fuzzy control approach and shows that the fuzzy control approach could provide an effective framework for robust control of traffic routing in communications networks. Research studies still need to be carried out to develop fuzzy adaptive routing on different network structures and to evaluate its impact on performance     

异步光分组交换网的流量建模

研究了异步光分组交换网的流量特性，提出了网络流量的解析模型和近似模型。研究表明，在采用计时门限光分组组装算法的情况下，如输入IP流具有短程相关特性(ShortRangeDependent)，则光分组的到达间隔时间呈负指数分布，光分组的长度趋于高斯分布。     

Fair packet discarding for controlling ABR traffic in ATM networks

The asynchronous transfer mode (ATM) Forum has chosen rate-based control as the flow control scheme for the available bit-rate (ABR) service. However, rate-based schemes can achieve congestion control only if all users act in a cooperative manner. Even a limited number of uncooperative users can cause congestion collapse. We propose a mechanism called fair packet discarding to provide incentives to users to participate in network congestion control so that the network can operate in a more efficient manner     

A lockfree shared memory design for high‐throughput multicore packet traffic capture

Earlier study by this author has shown that traffic can be captured in multicore architectures with negligible overhead, thus introducing the topic of multicore parallelization into packet traffic analysis. Designs that involve locking or message passing are considered default in parallel processing, which is incompatible with packet traffic with its high throughput and small grain. This paper proposes a new design for shared memory which can be used by any number of processes completely lockfree. Analysis of processing overhead and C/C + + implementation of the design are presented. Copyright © 2014 John Wiley & Sons, Ltd.