int main (int argc, char **argv)
{
   Arg("AWsize", AWsize, 2);
   Arg("queuelimit", queuelimit, 30); 
   
//[color="Red"]   
Arg::ProcessArgs(argc,argv);
   if (Arg::Specified("trace"))
   {
     std::cout<< "trace is specified" << std::endl;
   }
   std::cout << "Advertised window size specified is " << AWsize << " packets" << std::endl;
   std::cout << "Queue limit specified is " << queuelimit << " packets" << std::endl;
    
   AWsize = AWsize * 8; //window size converted from packets to bytes

   Validation::Init(argc,argv);
   Simulator s;

//[/color]   

Trace* tr = Trace::Instance();
   Queue* qu;
   tr->IPDotted(true);
   tr->Open("assign1.txt");
   TCP::LogFlagsText(true);
   IPV4::Instance()->SetTrace(Trace::ENABLED);

   TCP* a;

   Node* c1 = new Node();
   Node* s1 = new Node();
   Node* r1 = new Node();
   Node* r2 = new Node();

   c1->SetLocation(0,0);
   s1->SetLocation(4,0);
   r1->SetLocation(1,0);
   r2->SetLocation(3,0);

#ifdef HAVE_QT
  c1->Color(Qt::blue);
  s1->Color(Qt::blue);
  r1->Color(Qt::red);
  r2->Color(Qt::red);
#endif
   Linkp2p l(Rate("10Mb"), Time("10ms"));

   c1->AddDuplexLink(r1, l, IPAddr("192.168.0.1"));
   s1->AddDuplexLink(r2, l, IPAddr("192.168.0.2"));

   Linkp2p r(Rate("1Mb"), Time("10ms"));

   r2->AddDuplexLink(r1, r);

//segmentation error occurs while executing the code shown below.
//[color="Red"]
   a->SetAdvertisedWindow(16);
   qu->DefaultLimitPkts(30);
   qu->Animate(true);
//[/color]
 }

   Queue* qu;
   TCP* a;

a->SetAdvertisedWindow(16);
qu->DefaultLimitPkts(30);
qu->Animate(true);