NS2 Research Issues NS2 Research Issues
What is simulation? *
system under study(has deterministic rules governing its behavior)
Real time inputsto system
(the environment)
system boundary
observer
“real” life
computer programsimulates deterministic rules governing behavior
psuedo random inputsto system
(models environment)
program boundary
observer
“simulated” life
Next: Why Simulation?
Why Simulation? *
• real-system not available, is complex/costly• quickly evaluate design alternatives (eg: different system
configurations)• evaluate complex functions for which closed form formula
or numerical techniques not available
Next: Wireless Network Simulation Areas
• WLAN• Ad-hoc Network• MANET• Sensor Network• Mesh Network• WiMax• MobileIP
Wireless Network Simulation Areas
Next: Research Focus in Wireless Network
5
Research focus in Wireless Network
• Routing protocols– Reactive, proactive, hybrid
• Cluster management– To reduce overhead, to facilitate network management, to
enable QoS, etc.• Quality of service (QoS)– Differentiating among different types of applications
• Medium access– Closing the link, recognizing neighbors, scheduling
transmission, etc.• Other– TCP performance in MANETs, etc.
Next: Methods for Network Research
advantage disadvantageExperiment • realistic • expensive
• sometimes not possible
Mathematical model
• insight •assumptions
Simulation • easy (cheap)• verification
• not much insight• assumptions
Methods for network research
Next: Types of Simulators
• NS/2NS/2 OpenSourceOpenSource• OPNETOPNET CommercialCommercial• OMNET++OMNET++ OpenSource, CommercialOpenSource, Commercial• QualNetQualNet CommercialCommercial• GlomosimGlomosim OpenSourceOpenSource• SSFNETSSFNET OpenSourceOpenSource• JsimJsim OpenSourceOpenSource• PDNSPDNS OpenSourceOpenSource• OpenWNSOpenWNS OpenSourceOpenSource
Type of Simulators
Next: Description about Simulators
NS/2:
Type: Event Based SimulatorSupport: Wired, WLAN, Ad-hoc, MANET, Sensor, Parallel,
Distributed, Optical, P2P, Bluetooth NetworksDevelopment: Up-to-date, Ver. 2.35
Opnet
Type: Fast discrete Event Based SimulatorSupport: Wired, WLAN, Ad-hoc, MANET, VoIP, IPv6,
Distributed, Optical, Grid, Cloud NetworksDevelopment: Up-to-date, GUI, Ver.9.1
Descriptions about Simulators
Next: Description about Simulators
OMNET++:
Type: Component Based SimulatorSupport: Wired, WLAN, Ad-hoc, MANET, Internet,
Optical, ATM, IP Multicast Networks.Development: Up-to-date, GUI, Ver.4.1
Qualnet
Type: Modeling Event Based SimulatorSupport: Wired, WLAN, Ad-hoc, MANET, Sensor, Parallel,
Distributed, Optical NetworksDevelopment: Up-to-date, GUI, Ver.4.5.1
Descriptions about Simulators
Next: Description about Simulators
Glomosim:
Type: Discrete-event Based SimulatorSupport: Wired, WLAN, Ad-hoc, MANET.Development: Final Release 2004, Ver.2.0
SSFNET - Scalable Simulation Framework
Type: Scalable Based SimulatorSupport: Wired, WLAN, Ad-hocDevelopment: Final Release 2004, Ver.2.0.0
Descriptions about Simulators
Next: Discrete Event Based Simulators
• ns-2 is an discrete event driven simulation– Physical activities are translated to events– Events are queued and processed in the order of their scheduled
occurrences– Time progresses as the events are processed
1 2
Time: 1.5 sec Time: 1.7 sec
Time: 1.8 secTime: 2.0 sec
Discrete Event Based Simulator
Next: What is NS-2
What is NS-2
• NEST (Network Simulation Testbed) REAL (Realistic and Large) NS-1 NS-2
• NS-2 is a common network simulator• NS-2 is Open Source Simulator (Gnu Licensed)• NS2 is publicly available at http://www.isi.edu/nsnam/ns/ns-
build.html
Next: NS-2 Versions
NS2 Versions
NS1 Version:NS1 Version:
NS2 Version:NS2 Version:
Wireless external support - CMU MonarchVersion: 2.1b3,2.1b4,2.1b5…9Efficient Version:2.1b7,2.1b92.1b7,2.1b9
Wireless Internal supportVersion: 2.26,2.27……..2.35Efficient Version:2.27,2.29,2.31,2.342.27,2.29,2.31,2.34
Next: NS-2 Download
Ns-all-in-one Package
NS2 Package Linux Supporting Package
TCL/Tk – Tool Command language/Tool Kit
NS – Network Simulator
Nam – Network Animator
Xgraph – Graph Visualizer
Otcl – Object Tcl
GCC – Gnu C++ Compiler
Awk – Analysis Script
Perl – Analysis Language
Gnuplot – Graph Plot
Next: NS Component Model Design
NS Component Model Design
Simulator
Animator
Pre-Processing
Post-Processing
Analysis
Core Design
NS Simulator
Network Animator
Traffic & TopologyGenerator
Trace Analysis
Protocol & Algorithm
Graph Visualization
1
2
3
4
5
6
Next: NS-2 Development Structure
NS2 Development Structure
Core ModelCore Model Architecture ModelArchitecture Model Analysis ModelAnalysis Model
Language: C++C++Compiler: GCCGCC
Language: TCL/TKTCL/TKCompiler: NSNS
Language: PerlPerlScript: AwkAwkCompiler: PerlPerl
Aodv.ccTcp.ccUdp.ccMac.cczzz.cc
Compiler-GCC
Aodv.oTcp.oUdp.oMac.ozzz.o
Stage 1: Stage 2: Stage 3:
1
4
2
3
S
DMAC
AODV
TCP
oTcl
C++
TCL/Tk Compiler-NS
Nam
Trace
Analysis-Perl,Awk
Data
Gnuplot Xgraph
11
22
33
44
55
66Next: Types of Installation
Types of Installation
1. Direct Installation : Linux1. Disadvantage: Separate Partition2. Complex Windows Integration
2. Using CygWin :
1. Disadvantage: Poor Update Performance2. Complex Add-ons Integration
3. Using Vmware :1. Advantage: Restorable2. Easy Integration
Next: Requirements