$count ++;
if ($count == 500) {
   $MAXLEN = 1024;
   $PORTNO = 5151;
   $sock = IO:SOCKET::INET->new(LocalPort => $PORTNO, Proto => 'udp')
       or die "socket:  $@";
   if ($sock->recv($request, $MAXLEN))  {
        ...
        close($sock);
        }
        $count = 0;
      }