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EuQoS E-Learning module: Implementing Protocols on Network Simulators

RVS Seminar EuQoS E-Learning module: Implementing Protocols on Network Simulators
Jana Kr?henbühl University of Berne

June 15, 2005

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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Table of Contents
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Scope of the E-Learning module Packet Model Network Simulation Fluid Model Network Simulation Related Work: Hybrid Network Simulation VAT4Net Outlook & Planned Work Questions References

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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Scope of the E-Learning module
Module Name: Implementing Protocols on Network Simulators > General module information: - part of EuQoS E-Learning Portal - EuQoS Didactics and Design Guide (Version 0.9) > Theory - general introduction to network simulation - comparison of different network simulators available - ns-2 - wireless network simulation & protocol implementation > Practical Exercises: - Hands-on Session: (1) first part will be a short introducing example and a more complex TCL script (2) implementing a protocol in C++ and TCL
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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Packet & Fluid Simulation Model
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Packet Model: - used for protocol design and evaluation - each packet is tracked individually - packet losses are computed deterministically - Problem: great need of computation time and memory - Examples: ns-2, Qualnet, Omnet++

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Fluid Model: - used for performance analysis and bottle necks - packet flows are modelled as fluid flowing through pipes - simulator keeps track of the fluid rate changes - Problem: reduced accuracy in the output data with lot of estimated variables and average behavior - Examples: Mathlab code export into Qualnet

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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Hybrid Network Simulation
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Leverage strong points of fluid and packet modeling methods results in computational efficient simulation

Fluid model to represent aggregations of flows for which less detail is required – background flows > Packet model to represent individual flows with more detail – foreground flows
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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Hybrid Network Simulation – Foreground and Background Flows [1]
>HDCF-NS fluid model simulator

for background flows >pdns for packet level simulation
>Exchanging information at

run-time >Time management and message exchange with RTIKIT >Same network topology, same queue limits and link capacities >pdns simulator enhanced with a FluidQueue with fluid level and rate change indicator

June 15, 2005

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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Hybrid Network Simulation – Hybrid Buffer [2]
>Adding a new type of output

buffer to network links >IP-TN simulator with fluid modeling
>Hybrid buffer models a FIFO

operating queue in three modes: packet, fluid or hybrid mode

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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Hybrid Network Simulation – Buffer

αp(t) αf(t) βf(t) Xc X(t) λ l(t)

input rate packet flows input rate fluid flows output rate fluid flows buffer capacity buffer usage buffer service rate loss rate

> Both flows are handled in one buffer > αp(t) is estimated when packet arrives at the buffer: sum of last X packet size divided by the time interval of arrival > αp(t) and αf(t) added get the overall aggregate input rate α(t)

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EuQoS E-Learning module: Implementing Protocols on Network Simulators

VAT4Net (1) – Project Overview
Visualization and Animation Tool for Network Simulations SOURCEFORGE.net (vat4net.sourceforge.net) Team Jana Kr?henbühl, Thomas Bernoulli, Thomas Staub License GPL Technology Java 1.4.2 (Java Swing, Java Reflection API) Application Stand-alone or applet version Formats NAM trace format (other formats in planning) USE > Main scope: - providing a tool for model analysis in the simulation process > Use in EuQoS Module: - the E-Learning module should provide all required tools online Topic
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EuQoS E-Learning module: Implementing Protocols on Network Simulators

VAT4Net (2) – Demo

Demo
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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Outlook & Planned Work
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Finishing module until next deadline from EuQoS in September 2005 Further development for VAT4Net: - add support for various trace file formats - extend statistical analyse possibilities - improve animation interface - enhance the applet mode with ssh-support

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EuQoS E-Learning module: Implementing Protocols on Network Simulators

Questions

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EuQoS E-Learning module: Implementing Protocols on Network Simulators

References
[1] George F. Riley and Talal M. Jaafar and Richard Fujimoto, “Integrated Fluid and Packet Network Simulations.”, MASCOTS, 2002, pp. 511-518 [2] Cameron Kiddle, Rob Simmonds, Carey Williamson, Brian Unger, University of Calgary, “Hybrid Packet/Fluid Flow Network Simulation”, Seventeenth Workshop on Parallel and Distributed Simulation, 2003, pp. 143 [3] Sandeep Bajaj and Lee Breslau et al., University of Southern California, ?Improving Simulation for Network Research “, 1999, 99-702b [4] Tak Kin Yung, Jay Martin, Mineo Takai and Rajive Bagrodia, ?Integration of fluidbased analytical model with Packet-Level Simulation for Analysis of Computer Networks“

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