[ns] why not response!!!!
Mohammed Abu Hajar
mcsist at yahoo.com
Wed Nov 14 06:35:41 PST 2007
Creating random traffic-pattern for wireless scenarios
Random traffic connections of TCP and CBR (Constant Bit Rate) can be setup between mobile nodes using a traffic scenario generator script. This traffic generator script is available under ~/ns-2.28/indep-utils/cmu-scen-gen and is called cbrgen.tcl. The command line looks like the following:
ns cbrgen.tcl [-type cbr|tcp] [-nn nodes] [-seed seed] [-mc connections] [-rate rate]
Type of the generated traffic, TCP or CBR
Total number of nodes being simulated
Random number seed used to initialize part of the seed of various randomly generated numbers in the simulation. This can be used to vary the seed of the simulation to see the consistency of the results of the simulation
Number of flow connections
Number of packets per second.
cbr gensub-command explanation
The start times for the TCP/CBR connections are randomly generated with a maximum value set at 180.0s, thus the simulation time is at least 180 seconds, and the number of nodes has no relationship to the maximum number of connections.
A typical generated CBR traffic file looks like:
set udp_(1) [new Agent/UDP]
$ns_ attach-agent $node_(4) $udp_(1)
set null_(1) [new Agent/Null]
$ns_ attach-agent $node_(5) $null_(1)
set cbr_(1) [new Application/Traffic/CBR]
$udp_(1) set fid_ 1
$cbr_(1) set packetSize_ 512
$cbr_(1) set interval_ 0.25
$cbr_(1) set random_ 1
$cbr_(1) set maxpkts_ 10000
$cbr_(1) attach-agent $udp_(1)
$ns_ connect $udp_(1) $null_(1)
$ns_ at 56.333118917575632 "$cbr_(1) start"
A typical generated TCP (FTP) traffic file looks like:
set tcp_(0) [ new Agent/TCP ]
set sink_(0) [ new Agent/TCPSink ]
set ftp_(0) [ new Application/FTP ]
$tcp_(0) set class_ 1
$tcp_(0) set packetSize_ 512
$ns_ attach-agent $node_(1) $tcp_(0)
$ns_ attach-agent $node_(2) $sink_(0)
$ftp_(0) attach-agent $tcp_(0)
$ns_ connect $tcp_(0) $sink_(0)
$ns_ at 2.5568388786897245 "$ftp_(0) start"
$ns_ at $val(stop) "$ftp_(0) stop"
If you want to change the values you can use awk script to do that.
MSc of Computer Science
leticia bela <letissia07 at yahoo.fr> wrote:
Please can any one say me how can i change cbr rate during simulation for a given resource from my c++ file. or there are not solution for this ???????????????
thanks a lot!!!
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