#!d:\perli\bin\perl -w
#
#	UDP example
#
#	Traffic generator that sends DDP to 127.0.0.1 ports 2346 and 2347
#	using a catch up calculation
#

#
#	A  call generator starts a timer with a delay of $interArrivalTime 
#	$interArrivalTime  is calculated to have a negative exp distribution.
#
#	Alternatively, if you have a constant time tick and a probability 
#	of a call in this interval, you can work out if this time tick is 
#	to make a call.
#	
#	Alternatively, if you have a constant time tick You can catch up real 
#	time by adding the interarrival times to $nowTime and sending calls.
#	You can then start a timer and knock back $nowTime by the duration of the 
#	timer.  This is how this script works.
#	
#	
#

    #!/usr/bin/perl -w

    use strict;
    use Socket;
    use Sys::Hostname;
    my ( $count, $hisiaddr, $hispaddr, $histime,
         $host, $iaddr, $paddr, $port, $proto,
         $rin, $rout, $rtime, $SECS_of_70_YEARS);

    $SECS_of_70_YEARS      = 2208988800;

    # $iaddr = gethostbyname(hostname());


    $proto = getprotobyname('udp');
    $paddr = sockaddr_in(2345,inet_aton("127.0.0.1"));

    socket(SOCKET, PF_INET, SOCK_DGRAM, $proto)   || die "socket: $!";
    bind(SOCKET, $paddr)                          || die "bind: $!";
    $| = 1;
    printf "%-12s %8s %s\n",  "localhost", 0, scalar localtime time;

   

    my $message = "Message";


    for( $count = 0; $count < 100 ; $count++ ){
        $hispaddr = sockaddr_in(2345, inet_aton("127.0.0.1") );
        send(SOCKET, "$message $count \r\n", 0, $hispaddr) ;
        print $count." " ;
    }

    # Call Generator simulator code.

    my $ip;
    my $now; 
    my $CallsPerSecond = 4;
    my $timerTickTime  = 1;
    my $sum=0;
    my $interArrivalTime = -log( 1 - rand() ) / $CallsPerSecond;
   

    for( $count = 0; $count<1000 ; $count++ ){

       $interArrivalTime = -log( 1 - rand() ) / $CallsPerSecond;

       $sum = $sum + $interArrivalTime;
       print "$sum  $interArrivalTime \r\n"
    }
    my $sum = 0;
    my $StartedAt = time; 
    my $running = 0;
    my $callType;
    my $destination;

    # Catch Up calculation method. 
    # A fixed timer is used, and on each tick, 
    # calls are sent to catch up simulated time.

    my $nowTime = -5.0;
 
    while( 1 ) {

	if ( $nowTime > 0.0 ) { 

           # start timer for a fixed period 
           $count = select( undef, undef, undef, $timerTickTime ) ;
           $nowTime = $nowTime - $timerTickTime;

	} else {        
        # Catch up with calls
        # generate a time interval modulated by Neg Exp distribution
        $interArrivalTime = -log( 1 - rand() ) / $CallsPerSecond;
        $sum         = $sum + $interArrivalTime;
        $running     = time - $StartedAt;

	# Now pick a call type
	$callType    = int( rand()*10 );

	# Now pick a destination
	$destination = int( rand()*10 );


        #print "Call Generator: $running,$sum,$callType,$destination,$interArrivalTime \r\n";
 
        #$ip = <STDIN>;

	# Prepare Message
	# TS,Protocol,OrigID,DestID,Operation,P1,,,CRLF

        $message =  "$sum,0,0,$destination,MAKECAll,,,END\r\n";

        if ( rand() < 0.5 ) { 
          $hispaddr = sockaddr_in(2346, inet_aton("127.0.0.1") );
        } else {
          $hispaddr = sockaddr_in(2347, inet_aton("127.0.0.1") );
        }
        send(SOCKET, "CLG:,$message", 0, $hispaddr) ;


        print "Call Generator: $running,$sum,  $message";

	$nowTime = $nowTime + $interArrivalTime;
	}
    }