[ns] FW: 2 SCTP agents in the same node to a sink node through a middle node

Tue Nov 30 03:41:39 PST 2004

  _____  

From: ELSHEIKH, Mr Amr HIT/ISM 
Sent: Tuesday, November 30, 2004 1:40 PM
To: 'ns-users at isi.edu'
Subject: 2 SCTP agents in the same node to a sink node through a middle
node

Dear All:

* I'm making a simulation of 3 nodes

SCTP2                          SINK

|                                   |

N1----------N2---------------N3

|

SCTP1

*         Source of data linked to agents is a trace file

*         In the trace file always the first agents gives right results
while the second gives trash

Any one knows the reason?

I've attached dump for tracing SCTP

Script

Source data

SCTP2 data

 time

size

40

1033

80

289

120

829

160

409

200

111

240

1115

SCTP 1 data

time

size

0

1200

480

2551

960

2913

1440

3275

1920

3193

2400

3184

Received_SCTP

op

time

frm

to

type

size

flag

Field8

src

dest

Field11

tsn

r

0.102298

1

2

sctp

1248

-------

1

0

2

-1

11

r

0.142701

1

2

sctp

1500

-------

2

0.1

2

-1

13

r

0.143901

1

2

sctp

1500

-------

2

0.1

2

-1

14

As you see 1248=1200 + 48 (header)

While 1500 should be = 1036 + 48=1084?????????????????

SCRIPT

set ns [new Simulator]

$ns color 1 Blue

$ns color 2 Red

set nf [open die_hard_small_sctp.nam w]

$ns namtrace-all $nf

# added by amr to genrate readable trace file

set allchan [open die_hard_small_trace_sctp.txt w]

$ns trace-all $allchan

# define the trace format:

#Agent/SCTP set nam_tracevar_ true

#Agent/SCTP set tracevar_ true

# generate the sending node:

set send_node [$ns node]

# generate the router:

set router [$ns node]

$router shape "box"

# generate the receiving node:

set recv_node [$ns node]

# define the links between the nodes:

$ns duplex-link $send_node $router 10Mb 10ms DropTail

$ns duplex-link $router $recv_node 10Mb 10ms DropTail

# define the source and the source model:

set sctp_I [new Agent/SCTP]

$sctp_I set fid_ 1

$sctp_I set numUnrelStreams_ 1

$sctp_I set unordered_ 1

$ns attach-agent $send_node $sctp_I

set sctp_BP [new Agent/SCTP]

$sctp_BP set fid_ 2

$sctp_BP set numUnrelStreams_ 1

$sctp_BP set unordered_ 1

$ns attach-agent $send_node $sctp_BP

# define the destination: 

set snk [new Agent/SCTP] 

$ns attach-agent $recv_node $snk

$ns connect $sctp_I $snk

$ns connect $sctp_BP $snk

# define the destination: 

#set snk_I [new Agent/SCTP] 

#$ns attach-agent $recv_node $snk_I

#set snk_BP [new Agent/SCTP] 

#$ns attach-agent $recv_node $snk_BP

#$ns connect $sctp_I $snk_I

#$ns connect $sctp_BP $snk_BP

# generate the video trace file ("Verbose_Jurassic_64.dat" is only an
example):

set original_file_name_I die_hard_small_I.txt

set trace_file_name_I video_I.dat

set original_file_id_I [open $original_file_name_I r]

set trace_file_id_I [open $trace_file_name_I w]

set last_time_I 0

while {[eof $original_file_id_I] == 0} {

  gets $original_file_id_I current_line

  if {[string length $current_line] == 0 ||

      [string compare [string index $current_line 0] "#"] == 0} {

    continue  

  }

  scan $current_line "%d%s%d" next_time type length

  set time [expr ($next_time-$last_time_I)*1000]

  set last_time_I $next_time

  puts -nonewline $trace_file_id_I [binary format "II" $time $length]

}

close $original_file_id_I

close $trace_file_id_I

set original_file_name_BP die_hard_small_BP.txt

set trace_file_name_BP video_BP.dat

set original_file_id_BP [open $original_file_name_BP r]

set trace_file_id_BP [open $trace_file_name_BP w]

set last_time_BP 0

while {[eof $original_file_id_BP] == 0} {

  gets $original_file_id_BP current_line

  if {[string length $current_line] == 0 ||

      [string compare [string index $current_line 0] "#"] == 0} {

    continue  

  }

  scan $current_line "%d%s%d" next_time type length

  set time [expr ($next_time-$last_time_BP)*1000]

  set last_time_BP $next_time

  puts -nonewline $trace_file_id_BP [binary format "II" $time $length]

}

close $original_file_id_BP

close $trace_file_id_BP

# set the simulation end time:

set end_sim_time [expr 1.0*$last_time_BP/1000+0.100]

if { $last_time_I > $last_time_BP} {

   set end_sim_time [expr 1.0*$last_time_I/1000+0.100] 

  }

# read the video trace file:

set trace_file_I [new Tracefile]

$trace_file_I filename $trace_file_name_I

set video_I [new Application/Traffic/Trace]

$video_I attach-agent $sctp_I

$video_I attach-tracefile $trace_file_I

set trace_file_BP [new Tracefile]

$trace_file_BP filename $trace_file_name_BP

set video_BP [new Application/Traffic/Trace]

$video_BP attach-agent $sctp_BP

$video_BP attach-tracefile $trace_file_BP

# add error model by amr

#set err [new ErrorModel]

#$err set rate_ 0.01

#$err unit pkt

#$err ranvar [new RandomVariable/Uniform]

#$err drop-target [new Agent/Null]

#$ns link-lossmodel $err $router $recv_node

# start the simulation:

$ns at 0.0 {

  $send_node label "VIDEO-SERVER"

  $router label "IP-ROUTER"

  $recv_node label "VIDEO-CLIENT"

  $video_I start

  $video_BP start

}

# stop the simulation:

$ns at $end_sim_time {

  finish

}

proc finish {} {

  global ns nf allchan

  $ns flush-trace

  close $nf

  close $allchan

  exec nam die_hard_small_sctp.nam &

  exit 0

}

$ns run

Anyone can help???

Thanks.