Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” !...
Transcript of Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” !...
![Page 1: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/1.jpg)
George F. Riley Georgia Institute of Technology
Network Simulation in the Classroom for Teaching Networking Fundamentals
1
![Page 2: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/2.jpg)
History � ECE6110
� “CAD For Computer Networks” � First taught circa 1999
� 1999 – 2001 � Opnet Network Modeler
� 2001-2004 � NS-2
� 2005-2009 � GTNetS
� 2010 – Present � NS-3
2
![Page 3: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/3.jpg)
Purpose (intended) � How to design and create a network simulator � Discrete Event Processing and Event Handlers � Models for various Network Components
� Channels � Network Interfaces � Lots of others
� Construct Topologies � Nodes � Links � Queues
� Data demands (Applications) � Metrics
� Goodput, link utilization, packet loss, overhead, etc.
3
![Page 4: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/4.jpg)
Purpose (actual)
4
� Understand Behavior of Packet-Based Networks Under a variety of conditions
� Use Simulation as a tool, but moreover use it to measure some network behavior as independent variables are adjust, and anticipate and explain measured resuts.
� For example, � What is the performance of a TCP flow as a function of kernel
buffer size (receiver window), segment size, and queue limit? � How does performance vary if queue limit is in units of packets
versus units of bytes? � Under what conditions will the RED queuing method perform
better than the standard “FIFO” (Drop Tail) approach?
![Page 5: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/5.jpg)
Assignment 1
5
� Measure performance (goodput) of a single TCP flow through a single bottleneck link
� Vary the following parameters: � Segment size 128, 256, 512 � Queue Limit 2000, 8000, 32000, 64000 bytes � Window Size 2000, 8000, 32000, 64000 bytes
� Part 2 – 10 Simultaneous flows � Random start times for a short interval (0 to 100ms) � Observe and report on fairness
![Page 6: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/6.jpg)
Lab 1 – Sample Results
6
![Page 7: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/7.jpg)
Lab 1 – Sample Results
7
![Page 8: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/8.jpg)
Kevin Jeffay’s “Tuning Red” Paper
8
� Laboratory Experiment to compare RED vs. DropTail � Realistic? Web browsing models � “Simulated” performance of up to 4000 simultaneous web
browsing sessions � 100Mb to 10Mb bottleneck link � Varying queue size (DropTail) � Varying RED parameters (minTh,maxTh,maxP, Wq) � Compare Response Time
![Page 9: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/9.jpg)
Jeffay’s Topology
9
![Page 10: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/10.jpg)
Sample “Tuning Red” Result
10
![Page 11: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/11.jpg)
Sample “Tuning Red” Result
11
![Page 12: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/12.jpg)
Lab 2 – Compare RED to DropTail
12
� Construct arbitrary topology � At least two bottleneck links for every flow � Compare “Goodput” as a function of Red (various parameters)
and Drop Tail
� Form a Conclusion! � Which is better, RED or DropTail � Provide metrics to support the claim
![Page 13: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/13.jpg)
Lab 2 Sample Results
13
![Page 14: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/14.jpg)
Lab 2 Sample Results
14
![Page 15: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/15.jpg)
Wireless Measurements - RoofNet
15
� Aguayo, SigComm 2004 � Reports on a measurement study of Cambridge “RoofNet” � “Active measurement” approch
� Generate UDP traffic and random sources, measure packet delivery ratio at all others.
� Results highly variable and inconclusive � Performance of actual physical medium difficult to model
![Page 16: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/16.jpg)
The RoofNet Network
16
![Page 17: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/17.jpg)
RoofNet Sample Results
17
![Page 18: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/18.jpg)
RoofNet Sample Results 2
18
![Page 19: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/19.jpg)
Lab 3 – Wireless Efficiency Measurements
19
� Construct Mobile Wireless Network � 1km x 1km; 2km, 2km regions � Varying node count 20 to 1000 � Varying Transmitter power (1mW to 500mW) � Varying traffic intensity (0.1 to 0.9) � Varying routing protocol, OLSR, AODV
� Measure and report on “efficiency”
![Page 20: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/20.jpg)
Final Projects
20
� Worm Model Propagation � Recreate results from Sharif/Riley, 2005
� Compare network simulators 802.11 model � NS2, GTNetS,NS3 � Similar to Reddy/Riley 2006
� Tuning Red � Recreate the results from Jeffay 2004
� Compare ns-3 wireless models
![Page 21: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/21.jpg)
Jeffay Final Project, Sample Results
21
![Page 22: Network Simulation in the Classroom for Teaching ... ! ECE6110 ! “CAD For Computer Networks” ! First taught circa 1999 ! 1999 – 2001 ! Opnet Network Modeler ! 2001-2004](https://reader033.fdocuments.us/reader033/viewer/2022051308/5af141707f8b9ac57a8fa711/html5/thumbnails/22.jpg)
22
Questions?