My Ns2 Tutorial Final-Color

8/20/2019 My Ns2 Tutorial Final-Color

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Meivazhi Salai Andavargal

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The ns2 Tutorial

Prepared by

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Assistant Professor & HOD

Department of Electronics & Communication EngineeringSriram Engineering College, Perumalpattu – 602 024


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Procedure (default) to open x-desktop for ns2 simulation

Select ‘Startà

Cygwinà

Cygwin bash shell’

Type at cygwin bash shell ‘startx’ and press to open x-desktop

Type at x bash shell ‘CD/usr/local/ns*’ and

Press to move to ns2 installation folder

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Procedure (default) to create and save your TCL simulation scripts

Open ‘notepad’

Write your TCL simulation scripts

Select ‘Save as…’ from ‘File’ menu

Select ‘All Files’ for ‘Save as type’ from pop-up dialog

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Select ‘ANSI’ for ‘Encoding’

Type a name for the script file with ‘.tcl’ extension

Select ‘Save’


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Command to run a simulation scripts

#Command to run a simulation script

ns .tcl

scriptfilename Name of the simulation script file

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Steps to write a simulation script for ns2

@Create a simulator object

@ [Set nam or other tracing]

@Add nodes@ [Set node parameters]

@Add links

@ [Set link parameters]

@Add agents

@ [Set agent parameters]

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@ [Set connection parameters]

@Add traffics

@ [Set traffic parameters]

@ [Insert errors, network dynamics, routing]

@Set up event scheduling

@ [Create control loops or procedures]@Run simulation


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Steps to write a simulation script for ns2 (cont’d)

Please remember, in a TCL script,

´ Anything that follows the symbol ‘#’ in a line is a comment

´ Anything that is written in this color is a keyword

´ Anything that is written in this color is a user-defined pointer variable

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Create a simulator object

#Create a simulator object

set nsptr [new Simulator]

nsptr Pointer to simulator object

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Related commands

$nsptr version - Returns ns version

$nsptr now - Returns present time

$nsptr halt - Stop/pause simulation

$nsptr cancel - Cancels event event

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nsp r us - race – us es a race u ers n respec ve race es

$nsptr after – Schedule after a delay

$nsptr is-started - Returns true if simulator has started to run



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Set nam or other tracing

#Set nam tracing

#Open nam trace file

set ntfptr [open ntfname.nam ]#Set trace type

$nsptr $ntfptr

ntfptr Pointer to nam trace file ntfname created

ntfname Name of nam trace file

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r Read Only

w Read & Write

namtrace-all Trace all traffic

namtrace-queue $src $dst

Trace traffic between src & dst

nodes; hence declare only afterdeclaring link between src & dst


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Set nam or other tracing (cont’d)

#Set other tracing

#Open other trace file

set tfptr [open tfname.tr ]#Set trace type

$nsptr $tfptr

tfptr Pointer to trace file tfname created

tfname Name of trace file

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r Read Only

w Read & Write

trace-all Trace all traffic

trace-queue $src $dst

Trace traffic between src & dst nodes;

hence declare only after declaring linkbetween src & dst


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Add nodes

#Add nodes

set ndh [$nsptr node]

ndh Handle to node created


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Set node parameters

#Set node parameters

$ndh

color Color of node

shape Shape of node

“red”

“blue” And more for color

ndh Handle to node

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green

“circle”

“box”

“hexagon”

And more for shape


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Set node parameters (cont’d)

#Set node parameters

#Add label from specified time

$nsptr at “$ndh label \”\””

Schedule time in secs

Any text as label


ndh Handle to node

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Add links

#Add links

$nsptr $fnd $snd

simplex-link

duplex-link

Link type: simplex-link, unidirectional link;

duplex-link, bidirectional link

Link bandwidth in bps: add Mb for Mbps


fnd, snd Handles to pair of nodes to be linked

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Link delay in secs: add ms for milli secs

DropTail

FQ

SFQ

DRR

CBQ

RED

Queue type: Drop Tail, Fair Queue,

Stochastic Fair Queue, Deficit Round

Robin, CBQ, Random Early Discard


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Related commands

#Return instance variable head_ of link betweenfnd and snd

[$nsptr link $fnd $snd] head

#Return instance variable link_ of link between fnd and snd

[$nsptr link $fnd $snd] link

#Return instance variable queue_ of link between fnd and snd

[$nsptr link $fnd $snd] queue

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fnd, snd Handles to link nodes


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Set link parameters

#Set link parameters

$nsptr -op $fnd $snd

simplex-link

duplex-link

Link type: simplex-link, unidirectional link;

duplex-link, bidirectional link

color Color of link



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label Label for link

queuePos Queue position

“red”

“blue”

“green”

And more for color

“anytext” Any text as label

Number for queuePos


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Set link parameters (cont’d)

orient Setting node position for animation

right

Left

up

down

right-up

right-down

Orient second node to right of first node

Orient second node to left of first node

Orient second node straight up first node

Orient second node straight down first node

Orient second node to right of first node and up

Orient second node to right of first node and down

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left-upleft-down

up-right

down-right

up-left

down-left

Orient second node to left of first node and upOrient second node to left of first node and down

Orient second node up first node and right

Orient second node down first node and right

Orient second node up first node and left

Orient second node down first node and left

Orient second node at deg_double to left of first node


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#Set queue size of link

$nsptr queue-limit $fnd $snd

Queue size in packets



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#Set queue parameters of link

set qptr [[$nsptr link $fnd $snd] queue]

$qptr set



qptr Pointer to queue of link between fnd & snd

For all queue types

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limit_

blocked_

unblock_on_resume_

Queue size in packets

Enabling/disabling queue block

Enabling/disabling automatic queue unblock

true, false

true, false

Number of packets

If true, queue is blocked; unable to sent packet to link

If true, queue is unblocked after last pkt is txed.


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secsPerByte_ Seconds per byte

For Fair Queue (FQ)

maxqueue_

buckets_

Maximum queue in packets

Number of buckets used for hashing of flow

For Stochastic Fair Queue (SFQ)

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_

buckets_

blimit_

quantum_

mask_

Number of buckets used for hashing of flow

Shared buffer size in bytes

Flow rate in bytes

If true, flow consists of packets with same node id

true, false

For Deficit Round Robin (DRR)


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bytes_

queue-in-bytes_thresh_

maxthresh_

mean_pktsize_

q_weight_

wait_

linterm_

If true, byte-mode RED is enabled

If true, average queue size is measured in bytesMinimum threshold for average queue size in packets

Maximum threshold for average queue size in packets

Rough estimate of average packet size in bytes

Queue weight, used for calculating average queue size

If true, interval between dropped pkts is maintained

Packet dropping probability varies bet 0 and (1/linterm)

For Random Early Discard (RED)

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_drop-tail_

,If true, drop-tail is used when queue overflows

true, false

true, false

true, false

true, false

true, false


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Add agents

#Add agents

#Create desired agent

set agptr [new Agent/]#Attach agent to desired node

$nsptr attach-agent $ndh $agptr

agptr Pointer to agent created


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TCP

TCP/Reno

TCP/Newreno

TCP/Sack1

TCP/Fack

TCP senders

n Han e to no e to e attac e wit agent


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Add agents (cont’d)

TCP/FullTcp

TCP/Vegas

TCP/Vegas/RBPTCP/Reno/RBP

TCP/Asym

TCP/Reno/Asym

TCP/Newreno/Asym

TCP senders

TCPSink

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TCPSink/Asym

TCPSink/Sack1

TCPSink/Sack1/DelAck

TCP receivers

UDP UDP sender

Null Null receiver that simply discards received packets

RTP RTP sender/receiver


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LossMonitor Packet sink which checks for losses

IVS/Source IVS senderIVS/Receiver IVS receiver

CrtMcast/Encap Centralized multicast encapsulator

CrtMcast/Decap Centralized multicast de-encapsulator

Message Protocol to carry text messages

Message/Prune Processes multicast prune messages

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SRM SRM agent with non-adaptive timers

SRM/Adaptive SRM agent with adaptive timers

Tap Agent to interface simulator to live network

rtProto/DV Distance vector routing protocol agent


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Set agent parameters

#Set agent parameters

#For configurable parameters

$agptr set #For read only parameters

set pptr $agptr

agptr Pointer to agent created

pptr Pointer to parameter read

< arameter> Confi uration arameters common for all a ents

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fid_

prio_

agent_addr_

agent_port_

dst_addr_

dst_port_

An integer as flow ID

An integer as priority

An integer as address of this agent

Port no of this agent in integer

Destination address of this agent in integer

Destination port of this agent in integer

packetSize_ Packet size in bytes

Configuration parameters common for all source agents


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Set agent parameters (cont’d)

window_

maxcwnd_windowInit_

windowOption_

maxburst_

MSW

Upper bound on advertised window for TCP connection in packets

Upper bound on congestion window in packets-Set to 0 to ignoreInitial congestion window size in packets

Algorithm to handle congestion window (0 to 8)

Maximum no of packets to send in response to single ACK

Maximum window size in packets for TCP-window_


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Set agent parameters (cont’d)

nlost_

npkts_bytes_

lastPktTime_

expected_

Number of packets lost

Number of packets receivedNumber of bytes received

Time at which last packet was received

Expected sequence number of the next packet

State variables (read only) for only LossMonitor agent

#Set flow color for agents

$nsptr color

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Flow ID of agent considered

red

blue

green

And more as flow color



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Create connection

#Create connection

$nsptr connect $srcag $dstag


srcag Pointer to desired source agent

dstag Pointer to desired destination agent

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Add agents & Create connection-alternate

#Create desired agent, attach it to desired src node, connect it to desired dst

#node and returns ptr to src node createdset agptr [$nsptr create-connection $srcndh $dstndh

]

nsptr Pointer to simulator object created

Source agent

Destination a ent

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srcndh Pointer to source node

dstndh Pointer to destination node

agptr Pointer to source agent created


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Add agents & Create connection-alternate (cont’d)

#Create desired agent, attach it to desired src node, connect it to desired dst

#node and returns list of ptrs to src & dst nodes created

set agptrl [$nsptr create-connection-list $srcndh $dstndh

]

set sagptr [lindex $agptrl 0]

set dagptr [lindex $agptrl 1]


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Source agent

Destination agent

srcndh Pointer to source node

dstndh Pointer to destination node

agptrl List of pointers to source and destination agents created

sagptr Pointer to source agent created

dagptr Pointer to destination agent created


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Add traffics

#Add traffic

#Create traffic

set trptr [new Application/]#Attach it to desired agent

$trptr attach-agent $agptr

trptr Pointer to traffic created

agptr Pointer to desired agent

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FTP

Telnet

FTP traffic for TCP agent

Telnet traffic for TCP agent

Traffic/CBR

Traffic/Exponential

Traffic/Pareto

CBR traffic for UDP agent

Exponential traffic for UDP agent

Pareto traffic for UDP agent


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Set traffic parameters

#Set traffic parameters

$trptr set

packetSize_

rate_

Packet size in bytes

Traffic rate in bps

trptr Pointer to traffic created

For all traffic

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random_

maxpkts_

If true, random noise is introduced in traffic

Maximum number of packets

true, false

For CBR traffic


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Set traffic parameters (cont’d)

burst_time_

idle_time_

Length of burst (on-time) in secs

Length of off-time in secs

For Exponential traffic

burst_time_ Length of burst (on-time) in secs

For Pareto traffic

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_ _shape_

-Pareto shape parameter


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Set up event scheduling

#Set up event scheduling

$nsptr at “”



Any valid TCL command

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Set up event scheduling (cont’d)

#Selecting event scheduler before any event schedule

$nsptr use-scheduler

List

Heap

Calendar

ReatTime

Scheduler using a simple linked-list structure

Scheduler using a heap structure

Scheduler using a data structure analogous to year desk calendar

Scheduler using real time


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#Some important event schedules

#Start traffic trptr at time

$nsptr at “$trptr start”#Stop traffic trptr at time

$nsptr at “$trptr stop”


trptr Pointer to desired traffic

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#Annotating

$nsptr at “$nsptr trace-annotate \”\””

#Set nam animation rate$nsptr at “$nsptr set-animation-rate ”

#Finishing simulation

$nsptr at “finish”


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inis User- e ine inis proce ure; Re er to inis proce ure


Any text as annotation

Animation rate in secs


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Run simulation

#Run simulation

$nsptr run


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Creating procedures

#Creating procedures

proc pname {parg1 parg2 …} {pbody}

pname Procedure name by which it is called

parg1, parg2 Procedure arguments

pbody Procedure body i.e., list of TCL commands to be executed

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Creating procedures (cont’d)

#’finish’ procedure-a custom way to finish your simulation

proc finish {} {

#declaring nsptr, ntfptr as global variablesglobal nsptr ntfptr

#flush trace buffers to respective files

$nsptr flush-trace

#close all files

close $ntfptr

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open an ma on or s s mu a onexec nam .nam &

#exit procedure normally

exit 0

}


ntfptr Pointer to nam trace file ntfname



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Insert error model

#Create error model

set errmod [new ]

#Set errmodel parameters$errmod set

#Set target for droped packets

$errmod drop-target [new Agent/Null]

errmod Pointer to error model created

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ErrorModelErrorModel/Periodic

ErrorModel/Uniform

SelectErrorModel

ErrorModel/List

Simple error modelModeling periodic packet drop

Uniform error model

For selective packet drop

Dropping specified list of packets


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Insert error model (cont’d)

enable_

rate_

True if this error module is turned on

Uniform error rate in pkt or byte

For ErrorModel

unit_ Error unit in pkts, bytes or time

pkts,

bytes,

time

For all error models

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delay_bandwidth_

markecn_

delay_pkt_

Time to delay packetBandwidth of the link

If true, ecn is marked instead of dropping on corruption

If true, packet is delayed instead of dropping

true or false

true or false

true or false


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period_

offset_

burstlen_

default_drop_

Drop period in secs

Drop offset in secs

Drop length in secs

All pkts are dropped except last in period_ if true (1)

For ErrorModel/Periodic

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rue or a se


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enable_

rate_delay_

bandwidth_

markecn_

delay_pkt_

pkt_type_

drop_cycle_

True if this error module is turned on

Uniform error rate in pkt or byteTime to delay packet

Bandwidth of the link

Mark ecn instead of dropping on corruption?

Delay packet instead of dropping?

0,1 or 2 (TCP, UDP or CBR packet)

Drop pkts after every drop_cycle_

For SelectErrorModel

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drop_offset_ No of pkts to be dropped

true, false

true, false

true, false

0, 1 or 2


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cnt_

droplist_

dropcnt_

cur_

Count of pkts/bytes we've seen

Array of pkt/byte numbers to affect

Number of entries in droplist_ total

Current index into droplist_

For ErrorModel/List

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#Optional: Set random variable before setting drop-target

$errmod ranvar [new RandomVariable/]


ranvar Pointer to random variable created

Uniform, Exponential, Pareto,

ParetoII, Constant,

HyperExponential, Empirical,

Random variable type for random

generator

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orma , og orma , e u


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#Place error model on simple link just before the queue

$nsptr lossmodel $errmod $srcndh $dstndh

or#Place error model on simple link just after the queue

$nsptr link-lossmodel $errmod $srcndh $dstndh


nsptr Pointer to simulator object created

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srcn , s n o e an es o es re no e pa r


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#Generate random variable using desired distribution with desired parameters

set rng [new RNG]

$rng seed set ranvar [new RandomVariable/]

$ranvar set

$ranvar use-rng $rng

rng Pointer to random generator created

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ranvar Pointer to random variable created

Seed value for random generator

Uniform, Exponential, Pareto,

ParetoII, Constant,

HyperExponential, Empirical,

Normal, LogNormal, Weibull

Random variable type for random

generator


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min_

max_

Start value for distribution

End value for distribution

& Configurable parameters & their values for Uniform

avg_ Average value for distribution

& Configurable parameters & their values for Exponential

av Avera e value for distribution

& Configurable parameters & their values for Pareto & ParetoII

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_

shape_

_

Shape value for distribution

val_ Value for distribution

& Configurable parameters & their values for Constant

avg_

cov_

Average value for distribution

Covariance value for distribution

& Configurable parameters & their values for HyperExponential


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avg_

std_

Average value for distribution

Standard deviation value for distribution

& Configurable parameters & their values for Normal &

LogNormal

minCDF_

maxCDF_

interpolation_

maxEntr

0, 1 or 2

Min CDF value

Max CDF value

Interpolation method;

Size of CDF table

& Configurable parameters & their values for Empirical

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_ _

shape_

scale_

Shape for distribution

Scale for distribution

& Configurable parameters & their values for Weibull


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Insert network dynamics

#Set network dynamics

$nsptr rtmodel $src $dst

or$nsptr rtmodel-at $src $dst

Trace Up/down the link as per a trace file tracefile


src, dst Handles to src & dst nodes of link

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ExponentialDeterministic

Manual

Up/down the link exponentially as per Up/down the link deterministically as per

Up/down the link manually

$tracefile

{ }

{ }

Trace file already opened

Time schedule, all in secs

Time schedule, all in secs

Schedule time in secs and link status


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Insert network dynamics (cont’d)

, ,

,

stt-start time; upp-link-up interval; dnp-link-

down interval; fin-stop time


up or down Up or down the link

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Insert network dynamics (cont’d)

#Simply upping and downing a link e.g., link srcà dst

#Getting link_ for link of interest

set lin [$nsptr link $src $dst]#Setting link srcà dst as dynamic

$lin dynamic

#Scheduling link dynamics for link srcà dst

$nsptr at “$lin ”

lin

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src, dst Handles to nodes on link srcà dst

up or down Up or down the link



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Insert routing

#Select routing protocol

$nsptr rtproto

Static

Session

DV

LS

Static or Shortest Path routing algorithm

Session routing algorithm

Distance Vector routing algorithm

Link State routing algorithm


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Manualhierarchical

ManualHierarchical routing algorithm

$n0 $n1 ...

Selected routing algorithm applied to selected list

of nodes; if not specified, selected algorithm

applies to all nodes


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Insert routing (cont’d)

#Steps for manual routing

#Enable manual routing with rtproto

$nsptr rtproto Manual #Set default routes for all pairs of src and dst that are linked in given

#topology, if srcà dst is simplex-link, as

[$src get-module “Manual”] add-route-to-adj-node -default $dst

#or if srcà dst is duplex-link, add default route for reverse link also as

[$dst get-module “Manual”] add-route-to-adj-node -default $src

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src, dst Pair of nodes that are linked in given topology

$n0 $n1 ...

Selected routing algorithm applied to selected list

of nodes; if not specified, selected algorithm

applies to all nodes


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Insert routing (cont’d)

#Set actual route for a pair of src and dst if desired path between them is

#e.g., srcà imn1 and imn1à dst, if srcà imn1 & imn1à dst are simplex-link, as

[$src get-module “Manual”] add-route-to-adj-node $imn1[$imn1 get-module “Manual”] add-route-to-adj-node $dst

#or if srcà imn1 & imn1à dst are duplex-link, set reverse path

#dstà imn1 & imn1à src also as

[$dst get-module “Manual”] add-route-to-adj-node $imn1

[$imn1 get-module “Manual”] add-route-to-adj-node $src

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src, dst, imn1 Nodes that are linked in given topology


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Creating LAN

#Steps to create a LAN

#Step 1: Create new simulator object

#Step 2: Set NAM tracing

#Step 3: Add nodes

#Step 4: Add links if required

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#Step 5: Create LAN including all or some nodes created

#Step 6: Add agents & Add traffics

#Step 7: Set event scheduling

#Step 8: Run simulation


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Creating LAN (cont’d)

#Step 5: Creating LAN and adding all or some nodes created

$nsptr make-lan

orset lanptr [$nsptr newLan

]

“ ”


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…

Bandwidth in bps

Delay in secs

LL (Data) Link Layer

Queue/DropTail Interface queue type

Mac/Csma/Cd

Mac/Csma/Ca

CSMA/CD LAN protocol

CSMA/CA LAN protocol


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Creating LAN (cont’d)

Mac/802_3

Mac/802_11

10Mbps LAN connectivity

Wireless LAN protocol

Channel

WirelessChannel

Channel type for wired LAN

Channel type for wireless LAN

Phy/WiredPhy

Phy/WirelessPhy

Network interface for wired LAN

Network interface for wireless LAN

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Creating mobile network

#Steps to create a mobile network

#Step 1: Set mobile net options

#Step 2: Set parameters for selected mobile net options#Step 3: Create new simulator object

#Step 4: Set nam and other tracings

#Step 5: Create topography and GOD for mobile net

#Step 6: Set mobile node configurations

#Step 7: Create nodes as many as nmn

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ep : e n a pos ons an s zes or mo e no es#Step 9: Set scheduled or random movements for mobile nodes

#Step 10: Add agents, Connect them and Add traffics

#Step 11: Set event scheduling for traffics

#Step 12: Reset nodes when simulation ends

#Step 13: Stop nam when simulation ends

#Step 14: Call ‘finish’ to finish


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Creating mobile network (cont’d)

#Step 1: Define mobile net options

set opt(chan)

set opt(prop) set opt(phy)

set opt(mac)

set opt(ifq)

set opt(ll)

set opt(ant)

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se op q en < q en>set opt(nmn)

set opt(rtp)

set opt(x)

set opt(y)

set opt(seed)

set opt(stp)


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Channel/WirelessChannel Channel type Propagation/TwoRayGround Radio-propagation model

Phy/WirelessPhy Network interface type

Mac/802_11 Mac type

Queue/DropTail/PriQueue Interface queue type for dsdv

opt() Array to options

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LL Link layer type

Antenna/OmniAntenna Antenna type

Maximum queue length in packets

Number of mobile nodes


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DSDV

DSR

TORAAODV

Destination Sequence Distance Vector

Dynamic Source Routing

Temporally ordered Routing AlgorithmAdhoc On-demand Distance Vector

X dimension of topography

Y dimension of topography

Seed for random num generation

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mu a on en me n secs


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#Step 2: Set Phy/WirelessPhy parameters

Phy/WirelessPhy set

CPThresh_

CSThresh_

RXThresh_

Pt_

freq_

L_

Capture threshold in dB

Carrier sense threshold in watts

Receive power threshold in watts

Transmitted signal power in watts

Frequency in Hz

System loss factor

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#Step 2: Set LL parameters

LL set

mindelay_

delay_

bandwith_

Minimum delay in secs

Delay in secs

Bandwith in bps

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_


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#Step 2: Set Antenna/OmniAntenna parameters

Antenna/OmniAntenna set

X_

Y_

Z_

Gt_

Gr_

X position of antenna

Y position of antenna

Z position of antenna

Transmitting gain of antenna in dB

Receiving gain of antenna in dB

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_


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#Step 4: Set nam & other tracings

set ntfptr [open ntfname.tr ]

$nsptr namtrace-all-wireless $ntfptr $opt(x) $opt(y)

ntfptr Pointer to nam trace file ntfname



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r

w

Read only

Read/write or create


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#Step 5: Create topography & GOD for mobile net

set topo [new Topography]

$topo load-flatgrid $opt(x) $opt(y)

create-god $opt(nmn)

topo Pointer to new topography created

opt(val) Respective opt array element

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#Step 6: Set mobile node configurations

$nsptr node-config $

-addressingType

-adhocRouting

-llType

-macType

-propType

-if T e

usually flat or hierarchical used for wireless topologies

Adhoc rotuing protocol like DSDV, DSR, TORA, AODV etc

LinkLayer

MAC type like Mac/802_11

Propagation model like Propagation/TwoRayGround

Interface ueue t e like ueue Dro Tail Pri ueue

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-ifqLen-phyType

-antType

-channelType

-topoInstance

-wiredRouting

-mobileIP

-energyModel

Interface queue length like 50Network inteface type like Phy/WirelessPhy

Antenna type like Antenna/OmniAntenna

Channel type like Channel/WirelessChannel

Topography instance

Turning wired routing ON or OFF

Setting the flag for mobileIP ON or OFF

EnergyModel type

opt(val) Respective opt array element already defined


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initialEnergy

rxPower

txPower

agentTrace

routerTrace

macTrace

movementTrace

Specified in Joules

Specified in W

Specified in W

Tracing at agent level turned ON or OFF

Tracing at router level turned ON or OFF

Tracing at mac level turned ON or OFF

Mobilenode movement logging turned ON or OFF

opt(val) Respective opt array element already defined

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#Step 8: Set initial positions and sizes for mobile nodes

$ndh set

$nsptr initial_node_pos $ndh

ndh Handle to node


X_ X coordinate

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_

Z_

Z coordinate


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#Step 9: Set scheduled or random movements for mobile nodes

#For scheduled movements

#Set random-motion false for scheduled motions to take place

$ndh random-motion 0

$nsptr at “$ndh setdest ”


< > X and Y coordinates for new osition

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_

Speed of movement in m/s

#For random movements

$ndh random-motion

$nsptr at “$ndh start”


true or false

0 or 1Random motion of node ndh is enabled if true or 1


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#Step 12: Reset nodes when simulation ends

$nsptr at $opt(stp) “$ndh reset”nsptr Pointer to simulator object

ndh Handle to node


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#Step 13: Stop nam when simulation ends

$nsptr at $opt(stp) “$ndh nam-end-wireless $opt(stp)”


ndh Handle to node


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# Step 14: Call ‘finish’ to finish

$nsptr at “finish”

proc finish {} {

#declaring nsptr, ntfptr as global variables

global nsptr ntfptr

#flush trace buffers to respective files

$nsptr flush-trace

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close $ntfptr

#stop simulation-not necessary if step 13 is used

$nsptr halt

#open animation for this simulation

exec nam .nam &

exit 0

}

Documents

My Ns2 Tutorial Final-Color