Fortschritt-Berichte VDI

Transcription

1 Fortschritt-Berichte VDI Reihe 10 Informatik/ Kommunikation Dipl.-lnform. Helmut Gogl, Munchen Nr. 670 Measurement and Characterization of Traffic Streams in High-Speed Wide Area Networks VDI Verlag

2 V Contents 1 Introduction The Traffic Engineering Tasks Previous Work in Measurement and Characterization of Network Traffic This Work in Comparison to Previous Research Thesis Outline 9 2 The Asynchronous Transfer Mode Basics of the Asynchronous Transfer Mode (ATM) Cell Transport and Statistical Multiplexing ATM Cell Format ATM Virtual Connections The ATM Protocol Layers Protocol Reference Model Physical Layer (PL) ATM Layer ATM Adaption Layer (AAL) IP over ATM 21 i Measurement Techniques for High-Speed Networks Network Performance Aspects Performance Analysis vs. Traffic Characterization Network Traffic Measurement Techniques Classification of Network Monitors Software Monitor Hardware Monitor Software vs. Hardware Monitors Evaluation of Hardware Monitoring Approaches Basic Architecture of a Hardware Monitor Classification and Evaluation of Hardware Monitor Architectures Simple PC-based Approach PC-based Approach with Supporting Hardware 34

3 VI Contents Dedicated Hardware Approach Concluding Remarks Concept(s) for Future High-Speed Network Monitoring Motivating Parallel Processing Parallel Processing Strategies Motivating Data Reduction Data Reduction Strategies Simple Slicing Techniques Improved Slicing Techniques Filter Techniques Online Traffic Analysis Supporting Long-Term Measurements Interconnection Alternative Concept Summary Network Monitoring Alternative Distributed Network Monitoring Principle Limitations/Problems of Distributed Network Monitoring Type of Data Collection Flow-Based Traffic View Traffic Data Reporting Distributed Monitoring vs. Hardware Monitoring 59 4 Environment for Traffic Analysis (ETA) Network Traffic Analysis Principle Online vs. Offline Processing Problems of Data Post-Processing and Data Analysis ' Purpose and Intention of ETA Basic Concept of ETA Architecture and Realization of ETA The Data Collection Layer The Data Post-Processing Layer The ETA Post-Processing Core The Database Management System The Structure of the Database The Import Filter The User Interface 75

4 Contents VII The Data Analysis/Visualization Layer ETA compared to related Systems MonETEN JAM NMAS SNUFFLE Comparison with ETA Future Extensions of ETA 87 5 Mathematical Background for Modern Network Traffic Analysis Stochastic Processes and Network Traffic Definition of Self-Similar Processes Properties of Self-Similar Processes Methods for Detection of Self-Similarity Aggregated Variance Plot Index of Dispersion for Counts (IDC) Periodogram Plot Local Whittle Estimator R/S Analysis Wavelet Based Hurst Estimation Network Traffic, (Heavy-tailed) Distributions, and Self-Similarity Methods for Estimation of Distributions Comparing Distributions using QQ-Plots Assessing Distributions Tail Behavior Remarks on (Non-)Stationarity and Time Series Analysis The Problem of (Non-)Stationarity Time Series Analysis (TSA) Measurement of WAN Traffic Network Configuration and Hardware Equipment The German Broadband Research Network Network Access Point at the B-WiN Entrance Traffic Types and Protocol Stacks at the Network Access Point Hardware used for Measurements Connecting the Measuring Device Description of the Measurements 125

5 [II Contents Overview of the Measurement Types Data Analysis Potentials 128 Characterization of WAN Data Traffic Critical Review of the "Bellcore Data" Mixing Ratio of Applications/Protocols Medium Time Scale Characterization at the ATM Layer Overall Traffic Profiles Profiles of Aggregate Traffic Profiles of Selected Applications Characteristics of the Counting/Workload Process Distribution of Cell Counts Testing for Stationarity Correlation in Cell Counts Degree of LRD/Self-Similarity Interpretation of H in Practice Small Time Scale Characterization at ATM and Packet Layer Measurements and General Traffic Characteristics Characteristics of the Inter-Arrival Process Distribution of Cell IATs Distribution of IP Packet IATs Distribution of IP Packet Sizes LRD in Cell/Packet IATs Characteristics of the Counting/Workload Process Distribution of Cell/Byte Counts Distribution of IP Packet Counts LRD in Cell/Packet Counts Analysis of Cell/Packet Bursts Principles of the Applied Burst Analysis Investigation of On- and Off-Periods Small Time Scale Characterization at the TCP Layer The Connection Stream Measurements Characteristics of the Connection Inter-Arrival Process Distribution of Connection IATs Distribution of Connection Counts Distribution of Connection Sizes 197

6 Contents IX LRD in Connection IATs/Counts Summary Characterization of WAN Multimedia Traffic Related Work (Video-)Telephony over IP Principles behind IP Telephony Technical Realization of IP Telephony The Connection Establishment Problem Extended Measurement Environment The considered Audio/Video Codecs Analysis of IP Video-Phone Traffic The IPHONE Measurements General IPHONE Traffic Characteristics Correlation Structure of IPHONE Traffic Cell Count/IAT Distribution of IPHONE Traffic Television Broadcast over IP using the MBONE Purpose and Concept of MBONE The Experimental Setup Analysis of MBONE Television Broadcast Traffic The MBONE Measurements General MBONE Traffic Characteristics Correlation Structure of MBONE Traffic Distribution of Cell Counts Audio/Video Transmissions over ATM The IKON Teleteaching Application The Experimental Setup Analysis of Native ATM Audio/Video Traffic The IKON Measurements General IKON Traffic Characteristics Correlation Structure of IKON Traffic Burst Length Distribution Summary Conclusion 250