network simulator 2 report file

7/24/2019 Network Simulator 2 Report File

1/13

M.S.RAMAIAH INSTITUTE OF TECHNOLOGY

DEPARTMENT OF INFORMATION SCIENCE AND ENGINEERING

(Autonomous Institute Affiliated to TU!

I"YA SOU"HA# M. S. R Na$a%# M. S. R. I. T. &ost# 'an$alo%e )*++),

CERTIFICATE

This is to certify that the following stuents! who were wor"ing uner #y guiance! ha$e

co#%lete their wor" as %er #y satisfaction with the to%ic Network Simulation 2-

OTcl script in wired network&

Anu%oo- R MS/IS+0

A1inas2 R MS/IS+3*

44444444444444444444

Signature of the GuieM%. Mani Se52a% S RAssistant Professor!

De%t& of ISE! MSRIT!'angalore()*


2/13


3/13

Network Simulator 2 - OTcl script in wired network

Introduction

NS (network simulator) is a discrete eventnetwork simulators, specifcally ns-

1, ns-2and ns-3. All o them are discrete-event network simulator, primarily used

in research and teaching. ns- is ree sotware, pu!licly availa!le under the "N#

"$%v& license or research, development, and use. 'he goal o the ns- proect is to

create an open simulation environment or networking research that will !e

preerred inside the research community.

t should !e aligned with the simulation needs o modern networking

research.

t should encourage community contri!ution, peer review, and validation o

the sotware.

Since the process o creation o a network simulator that contains a su*cient

num!er o high-+uality validated, tested and actively maintained models re+uires a

lot o work, ns- proect spreads this workload over a large community o users and

developers. 'his is the popular simulator in scientifc environment and other popular

network simulators are

"lomosim #%A, /#0 $arse, /o!ile Simulation mostly

1$N2' commercial sotware, graphical interace, not ree0

Two Languages: C++, OTcl

1'cl short or /' 1!ect 'cl, an e3tension to 'cl4'k or o!ect-oriented

programming.

5 #sed to !uild the network structure and topology which is ust the surace o your

simulatoion0

5 2asily to confgure your network parameters0
http://en.wikipedia.org/wiki/Discrete_event_simulationhttp://en.wikipedia.org/wiki/Network_simulationhttp://en.wikipedia.org/wiki/Free_softwarehttp://en.wikipedia.org/wiki/Discrete_event_simulationhttp://en.wikipedia.org/wiki/Network_simulationhttp://en.wikipedia.org/wiki/Free_software


4/13

5 Not enough or research schemes and protocol architecture adaption.

C++: ost im!ortant and kernel !art o" t#e NS2

5 'o implement the kernel o the architecture o the protocol designs0

5 6rom the packet 7ow view, the processes run on a single node0

5 'o change or 8comment out9 the e3isting protocols running in NS&0

5 :etails o your research scheme.

$rotocols%odels su!!orted &' NS2

5 ;ired Networking


5/13

) sim!le NS simulation scri!t: and e*!lains w#at eac# line does:

Breate a simulator o!ect

set ns Cnew SimulatorD

B:efne di?erent colors or data 7ows (or NA/)

Ens color F @lue

Ens color &


6/13

B:efne a GfnishG procedure

proc fnish HI H

glo!al ns n

Ens 7ush-trace

Blose the NA/ trace fle

close En

B23ecute NA/ on the trace fle

e3ec nam out.nam J

e3it K

I

Breate our nodes

set nK CEns nodeD

set nF CEns nodeD

set n& CEns nodeD

set n CEns nodeD

Breate links !etween the nodes

Ens duple3-link EnK En& &/! FKms :rop'ail

Ens duple3-link EnF En& &/! FKms :rop'ail

Ens duple3-link En& En F.L/! &Kms :rop'ail

BSet >ueue SiMe o link (n&-n) to FK

Ens +ueue-limit En& En FK

B"ive node position (or NA/)

Ens duple3-link-op EnK En& orient right-down

Ens duple3-link-op EnF En& orient right-up

Ens duple3-link-op En& En orient right

B/onitor the +ueue or link (n&-n). (or NA/)


7/13

Ens duple3-link-op En& En +ueue$os K.

BSetup a '$ connection

set tcp Cnew Agent4'$D

Etcp set classO &

Ens attach-agent EnK Etcp

set sink Cnew Agent4'$SinkD

Ens attach-agent En Esink

Ens connect Etcp Esink

Etcp set fdO F

BSetup a 6'$ over '$ connection

set tp Cnew Application46'$D

Etp attach-agent Etcp

Etp set typeO 6'$

BSetup a #:$ connection

set udp Cnew Agent4#:$D

Ens attach-agent EnF Eudp

set null Cnew Agent4NullD

Ens attach-agent En Enull

Ens connect Eudp Enull

Eudp set fdO &

BSetup a @< over #:$ connection

set c!r Cnew Application4'ra*c4@


8/13

Ec!r set randomO alse

BSchedule events or the @< and 6'$ agents

Ens at K.F PEc!r startP

Ens at F.K PEtp startP

Ens at Q.K PEtp stopP

Ens at Q. PEc!r stopP

B:etach tcp and sink agents (not really necessary)

Ens at Q. PEns detach-agent EnK Etcp 0 Ens detach-agent En EsinkP

Ball the fnish procedure ater seconds o simulation time

Ens at .K PfnishP

B$rint @< packet siMe and interval

puts P@< packet siMe R CEc!r set packetOsiMeODP

puts P@< interval R CEc!r set intervalODP

B


9/13


10/13


11/13


12/13

In general, an NS scri!t starts wit# making a Simulator o&ect instance

set nsCnew SimulatorD generates an NS simulator o!ect instance, and

assigns it to varia!le ns.

nitialiMe the packet ormat (ignore this or now)

reate a scheduler (deault is calendar scheduler)

Select the deault address ormat (ignore this or now)

'he PSimulatorP o!ect has mem!er unctions that do the ollowing

reate compound o!ects such as nodes and links (descri!ed later) onnect network component o!ects created (e3. attach-agent)

Set network component parameters (mostly or compound o!ects)

reate connections !etween agents (e3. make connection !etween a PtcpPand PsinkP)

Speciy NA/ display options

2tc.

$nscolor fd color is to set color o the packets or a 7ow specifed !y the7ow id (fd). 'his mem!er unction o PSimulatorP o!ect is or the NA/display, and has no e?ect on the actual simulation.

$nsnamtrace-all fle-descriptor 'his mem!er unction tells the simulator torecord simulation traces in NA/ input ormat. t also gives the fle name thatthe trace will !e written to later !y the command $ns7ush-trace. Similarly,the mem!er unction trace-allis or recording the simulation trace in ageneral ormat.

proc fnishHI is called ater this simulation is over !y the command $nsat.K PfnishP. n this unction, post-simulation processes are specifed.

set n0C$nsnodeD 'he mem!er unction nodecreates a node.

$nsduple3-link node1 node2 bandwidth delay queue-type creates two

simple3 links o specifed !andwidth and delay, and connects the twospecifed nodes.

$ns+ueue-limit node1 node2 number 'his line sets the +ueue limit o thetwo simple3 links that connect nodeF and node& to the num!er specifed.

$nsduple3-link-op node1 node2 ... 'he ne3t couple o lines are used or theNA/ display. 'o see the e?ects o these lines, users can comment these linesout and try the simulation.


13/13

Now t#at t#e &asic network setu! is done, t#e ne*t t#ing to do is tosetu! trac agents suc# as TC$ and ./$, trac sources suc# as 0T$and C

set tcpCnewAgent/T!D 'his line shows how to create a '$ agent. @ut ingeneral, users can create any agent or tra*c sources in this way. Agents and

tra*c sources are in act !asic o!ects (not compound o!ects), mostlyimplemented in and linked to 1'cl. 'hereore, there are no specifcSimulator o!ect mem!er unctions that create these o!ect instances. 'ocreate agents or tra*c sources, a user should know the class names theseo!ects (Agent4'$, Agnet4'$Sink, Application46'$ and so on).

$nsattach-agent node agent 'he attach-agentmem!er unction attaches anagent o!ect created to a node o!ect. Actually, what this unction does is callthe attachmem!er unction o specifed node, which attaches the givenagent to itsel. 'hereore, a user can do the same thing !y, or e3ample, EnKattach Etcp

$nsconnect agent1 agent2 Ater two agents that will communicate witheach other are created, the ne3t thing is to esta!lish a logical networkconnection !etween them. 'his line esta!lishes a network connection !ysetting the destination address to each othersG network and port address pair.

Assuming that all the network confguration is done, the ne3t thing to do is write asimulation scenario (i.e. simulation scheduling). 'he Simulator o!ect has manyscheduling mem!er unctions. =owever, the one that is mostly used is the ollowing

$nsat time "string" 'his mem!er unction o a Simulator o!ect makes thescheduler (schedulerO is the varia!le that points the scheduler o!ect created

!y Cnew SchedulerD command at the !eginning o the script) to schedule thee3ecution o the specifed string at given simulation time. 6ore3ample, $nsat 0.1 "$cbr start"will make the scheduler call a startmem!erunction o the @< tra*c source o!ect, which starts the @< to transmitdata.

Ater all network confguration, scheduling and post-simulation procedurespecifcations are done, the only thing let is to run the simulation. 'his isdone !y $nsrun.

THANK YOU.

network simulator 2 report file

Documents