Hi Daniweb,

I've have an assignment which is to modified the cpp script for ns2 simulation. I need to modify it so that the size is multiply by 2 over 10 interval and change back to the original size after 10 interval. I've changed the code in the modified field, but seems there are some compilation error which i don't know how to solve. I think mainly due to the <size_pointer> variable.
It's kinda urgent. Any help is appreciate.
Thanks.

/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) Xerox Corporation 1997. All rights reserved.
 *  
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linking this file statically or dynamically with other modules is making
 * a combined work based on this file.  Thus, the terms and conditions of
 * the GNU General Public License cover the whole combination.
 *
 * In addition, as a special exception, the copyright holders of this file
 * give you permission to combine this file with free software programs or
 * libraries that are released under the GNU LGPL and with code included in
 * the standard release of ns-2 under the Apache 2.0 license or under
 * otherwise-compatible licenses with advertising requirements (or modified
 * versions of such code, with unchanged license).  You may copy and
 * distribute such a system following the terms of the GNU GPL for this
 * file and the licenses of the other code concerned, provided that you
 * include the source code of that other code when and as the GNU GPL
 * requires distribution of source code.
 *
 * Note that people who make modified versions of this file are not
 * obligated to grant this special exception for their modified versions;
 * it is their choice whether to do so.  The GNU General Public License
 * gives permission to release a modified version without this exception;
 * this exception also makes it possible to release a modified version
 * which carries forward this exception.
 */

#include <stdlib.h>

#include "random.h"
#include "trafgen.h"
#include "ranvar.h"


/* 
 * Constant bit rate traffic source.   Parameterized by interval, (optional)
 * random noise in the interval, and packet size.  
 */

class CBR_Traffic : public TrafficGenerator {
 public:
    CBR_Traffic();
    virtual double next_interval(int&,int&);
    //HACK so that udp agent knows interpacket arrival time within a burst
    inline double interval() { return (interval_); }
 protected:
    virtual void start();
    void init();
    double rate_;     /* send rate during on time (bps) */
    double interval_; /* packet inter-arrival time during burst (sec) */
    double random_;
    int seqno_;
    int maxpkts_;
};


static class CBRTrafficClass : public TclClass {
 public:
    CBRTrafficClass() : TclClass("Application/Traffic/CBR") {}
    TclObject* create(int, const char*const*) {
        return (new CBR_Traffic());
    }
} class_cbr_traffic;

CBR_Traffic::CBR_Traffic() : seqno_(0)
{
    bind_bw("rate_", &rate_);
    bind("random_", &random_);
    bind("packetSize_", &size_);
    bind("maxpkts_", &maxpkts_);
}

void CBR_Traffic::init()
{
        // compute inter-packet interval 
    interval_ = (double)(size_ << 3)/(double)rate_;
    if (agent_)
        if (agent_->get_pkttype() != PT_TCP &&
            agent_->get_pkttype() != PT_TFRC)
            agent_->set_pkttype(PT_CBR);
}

void CBR_Traffic::start()
{
        init();
        running_ = 1;
        timeout();
}


double CBR_Traffic::next_interval(int& size, int& size_pointer)
{
    // Recompute interval in case rate_ or size_ has changes
    interval_ = (double)(size_ << 3)/(double)rate_;
    double t = interval_;
    if (random_)
        t += interval_ * Random::uniform(-0.5, 0.5);    

//modified field #####################################################  
    size_pointer = size_;
    size = size_;

    if (seqno_ % 10 == 0){
    if (size_pointer == size)
    size = size_*2;
    else
    size = size_/2;
    }
    else
    size = size_;

//modified field #####################################################  

    if (++seqno_ < maxpkts_)
        return(t);
    else
        return(-1); 
}

Edited 4 Years Ago by caven.chunyen_1

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